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freebsd-nq/sys/netinet/tcp_log_buf.c
Randall Stewart e854dd38ac An important statistic in determining if a server process (or client) is being delayed 
is to know the time to first byte in and time to first byte out. Currently we
have no way to know these all we have is t_starttime. That (t_starttime) tells us
what time the 3 way handshake completed. We don't know when the first
request came in or how quickly we responded. Nor from a client perspective
do we know how long from when we sent out the first byte before the
server responded.

This small change adds the ability to track the TTFB's. This will show up in
BB logging which then can be pulled for later analysis. Note that currently
the tracking is via the ticks variable of all three variables. This provides
a very rough estimate (hz=1000 its 1ms). A follow-on set of work will be
to change all three of these values into something with a much finer resolution
(either microseconds or nanoseconds), though we may want to make the resolution
configurable so that on lower powered machines we could still use the much
cheaper ticks variable.

Sponsored by:	Netflix Inc.
Differential Revision:	https://reviews.freebsd.org/D24902
2020-06-08 11:48:07 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2016-2018 Netflix, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/arb.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/qmath.h>
#include <sys/queue.h>
#include <sys/refcount.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/tree.h>
#include <sys/stats.h> /* Must come after qmath.h and tree.h */
#include <sys/counter.h>
#include <dev/tcp_log/tcp_log_dev.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_log_buf.h>
/* Default expiry time */
#define TCP_LOG_EXPIRE_TIME ((sbintime_t)60 * SBT_1S)
/* Max interval at which to run the expiry timer */
#define TCP_LOG_EXPIRE_INTVL ((sbintime_t)5 * SBT_1S)
bool tcp_log_verbose;
static uma_zone_t tcp_log_bucket_zone, tcp_log_node_zone, tcp_log_zone;
static int tcp_log_session_limit = TCP_LOG_BUF_DEFAULT_SESSION_LIMIT;
static uint32_t tcp_log_version = TCP_LOG_BUF_VER;
RB_HEAD(tcp_log_id_tree, tcp_log_id_bucket);
static struct tcp_log_id_tree tcp_log_id_head;
static STAILQ_HEAD(, tcp_log_id_node) tcp_log_expireq_head =
STAILQ_HEAD_INITIALIZER(tcp_log_expireq_head);
static struct mtx tcp_log_expireq_mtx;
static struct callout tcp_log_expireq_callout;
static u_long tcp_log_auto_ratio = 0;
static volatile u_long tcp_log_auto_ratio_cur = 0;
static uint32_t tcp_log_auto_mode = TCP_LOG_STATE_TAIL;
static bool tcp_log_auto_all = false;
static uint32_t tcp_disable_all_bb_logs = 0;
RB_PROTOTYPE_STATIC(tcp_log_id_tree, tcp_log_id_bucket, tlb_rb, tcp_log_id_cmp)
SYSCTL_NODE(_net_inet_tcp, OID_AUTO, bb, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
"TCP Black Box controls");
SYSCTL_BOOL(_net_inet_tcp_bb, OID_AUTO, log_verbose, CTLFLAG_RW, &tcp_log_verbose,
0, "Force verbose logging for TCP traces");
SYSCTL_INT(_net_inet_tcp_bb, OID_AUTO, log_session_limit,
CTLFLAG_RW, &tcp_log_session_limit, 0,
"Maximum number of events maintained for each TCP session");
SYSCTL_UMA_MAX(_net_inet_tcp_bb, OID_AUTO, log_global_limit, CTLFLAG_RW,
&tcp_log_zone, "Maximum number of events maintained for all TCP sessions");
SYSCTL_UMA_CUR(_net_inet_tcp_bb, OID_AUTO, log_global_entries, CTLFLAG_RD,
&tcp_log_zone, "Current number of events maintained for all TCP sessions");
SYSCTL_UMA_MAX(_net_inet_tcp_bb, OID_AUTO, log_id_limit, CTLFLAG_RW,
&tcp_log_bucket_zone, "Maximum number of log IDs");
SYSCTL_UMA_CUR(_net_inet_tcp_bb, OID_AUTO, log_id_entries, CTLFLAG_RD,
&tcp_log_bucket_zone, "Current number of log IDs");
SYSCTL_UMA_MAX(_net_inet_tcp_bb, OID_AUTO, log_id_tcpcb_limit, CTLFLAG_RW,
&tcp_log_node_zone, "Maximum number of tcpcbs with log IDs");
SYSCTL_UMA_CUR(_net_inet_tcp_bb, OID_AUTO, log_id_tcpcb_entries, CTLFLAG_RD,
&tcp_log_node_zone, "Current number of tcpcbs with log IDs");
SYSCTL_U32(_net_inet_tcp_bb, OID_AUTO, log_version, CTLFLAG_RD, &tcp_log_version,
0, "Version of log formats exported");
SYSCTL_U32(_net_inet_tcp_bb, OID_AUTO, disable_all, CTLFLAG_RW,
&tcp_disable_all_bb_logs, TCP_LOG_STATE_HEAD_AUTO,
"Disable all BB logging for all connections");
SYSCTL_ULONG(_net_inet_tcp_bb, OID_AUTO, log_auto_ratio, CTLFLAG_RW,
&tcp_log_auto_ratio, 0, "Do auto capturing for 1 out of N sessions");
SYSCTL_U32(_net_inet_tcp_bb, OID_AUTO, log_auto_mode, CTLFLAG_RW,
&tcp_log_auto_mode, TCP_LOG_STATE_HEAD_AUTO,
"Logging mode for auto-selected sessions (default is TCP_LOG_STATE_HEAD_AUTO)");
SYSCTL_BOOL(_net_inet_tcp_bb, OID_AUTO, log_auto_all, CTLFLAG_RW,
&tcp_log_auto_all, false,
"Auto-select from all sessions (rather than just those with IDs)");
#ifdef TCPLOG_DEBUG_COUNTERS
counter_u64_t tcp_log_queued;
counter_u64_t tcp_log_que_fail1;
counter_u64_t tcp_log_que_fail2;
counter_u64_t tcp_log_que_fail3;
counter_u64_t tcp_log_que_fail4;
counter_u64_t tcp_log_que_fail5;
counter_u64_t tcp_log_que_copyout;
counter_u64_t tcp_log_que_read;
counter_u64_t tcp_log_que_freed;
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, queued, CTLFLAG_RD,
&tcp_log_queued, "Number of entries queued");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, fail1, CTLFLAG_RD,
&tcp_log_que_fail1, "Number of entries queued but fail 1");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, fail2, CTLFLAG_RD,
&tcp_log_que_fail2, "Number of entries queued but fail 2");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, fail3, CTLFLAG_RD,
&tcp_log_que_fail3, "Number of entries queued but fail 3");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, fail4, CTLFLAG_RD,
&tcp_log_que_fail4, "Number of entries queued but fail 4");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, fail5, CTLFLAG_RD,
&tcp_log_que_fail5, "Number of entries queued but fail 4");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, copyout, CTLFLAG_RD,
&tcp_log_que_copyout, "Number of entries copied out");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, read, CTLFLAG_RD,
&tcp_log_que_read, "Number of entries read from the queue");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, freed, CTLFLAG_RD,
&tcp_log_que_freed, "Number of entries freed after reading");
#endif
#ifdef INVARIANTS
#define TCPLOG_DEBUG_RINGBUF
#endif
/* Number of requests to consider a PBCID "active". */
#define ACTIVE_REQUEST_COUNT 10
/* Statistic tracking for "active" PBCIDs. */
static counter_u64_t tcp_log_pcb_ids_cur;
static counter_u64_t tcp_log_pcb_ids_tot;
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, pcb_ids_cur, CTLFLAG_RD,
&tcp_log_pcb_ids_cur, "Number of pcb IDs allocated in the system");
SYSCTL_COUNTER_U64(_net_inet_tcp_bb, OID_AUTO, pcb_ids_tot, CTLFLAG_RD,
&tcp_log_pcb_ids_tot, "Total number of pcb IDs that have been allocated");
struct tcp_log_mem
{
STAILQ_ENTRY(tcp_log_mem) tlm_queue;
struct tcp_log_buffer tlm_buf;
struct tcp_log_verbose tlm_v;
#ifdef TCPLOG_DEBUG_RINGBUF
volatile int tlm_refcnt;
#endif
};
/* 60 bytes for the header, + 16 bytes for padding */
static uint8_t zerobuf[76];
/*
* Lock order:
* 1. TCPID_TREE
* 2. TCPID_BUCKET
* 3. INP
*
* Rules:
* A. You need a lock on the Tree to add/remove buckets.
* B. You need a lock on the bucket to add/remove nodes from the bucket.
* C. To change information in a node, you need the INP lock if the tln_closed
* field is false. Otherwise, you need the bucket lock. (Note that the
* tln_closed field can change at any point, so you need to recheck the
* entry after acquiring the INP lock.)
* D. To remove a node from the bucket, you must have that entry locked,
* according to the criteria of Rule C. Also, the node must not be on
* the expiry queue.
* E. The exception to C is the expiry queue fields, which are locked by
* the TCPLOG_EXPIREQ lock.
*
* Buckets have a reference count. Each node is a reference. Further,
* other callers may add reference counts to keep a bucket from disappearing.
* You can add a reference as long as you own a lock sufficient to keep the
* bucket from disappearing. For example, a common use is:
* a. Have a locked INP, but need to lock the TCPID_BUCKET.
* b. Add a refcount on the bucket. (Safe because the INP lock prevents
* the TCPID_BUCKET from going away.)
* c. Drop the INP lock.
* d. Acquire a lock on the TCPID_BUCKET.
* e. Acquire a lock on the INP.
* f. Drop the refcount on the bucket.
* (At this point, the bucket may disappear.)
*
* Expire queue lock:
* You can acquire this with either the bucket or INP lock. Don't reverse it.
* When the expire code has committed to freeing a node, it resets the expiry
* time to SBT_MAX. That is the signal to everyone else that they should
* leave that node alone.
*/
static struct rwlock tcp_id_tree_lock;
#define TCPID_TREE_WLOCK() rw_wlock(&tcp_id_tree_lock)
#define TCPID_TREE_RLOCK() rw_rlock(&tcp_id_tree_lock)
#define TCPID_TREE_UPGRADE() rw_try_upgrade(&tcp_id_tree_lock)
#define TCPID_TREE_WUNLOCK() rw_wunlock(&tcp_id_tree_lock)
#define TCPID_TREE_RUNLOCK() rw_runlock(&tcp_id_tree_lock)
#define TCPID_TREE_WLOCK_ASSERT() rw_assert(&tcp_id_tree_lock, RA_WLOCKED)
#define TCPID_TREE_RLOCK_ASSERT() rw_assert(&tcp_id_tree_lock, RA_RLOCKED)
#define TCPID_TREE_UNLOCK_ASSERT() rw_assert(&tcp_id_tree_lock, RA_UNLOCKED)
#define TCPID_BUCKET_LOCK_INIT(tlb) mtx_init(&((tlb)->tlb_mtx), "tcp log id bucket", NULL, MTX_DEF)
#define TCPID_BUCKET_LOCK_DESTROY(tlb) mtx_destroy(&((tlb)->tlb_mtx))
#define TCPID_BUCKET_LOCK(tlb) mtx_lock(&((tlb)->tlb_mtx))
#define TCPID_BUCKET_UNLOCK(tlb) mtx_unlock(&((tlb)->tlb_mtx))
#define TCPID_BUCKET_LOCK_ASSERT(tlb) mtx_assert(&((tlb)->tlb_mtx), MA_OWNED)
#define TCPID_BUCKET_UNLOCK_ASSERT(tlb) mtx_assert(&((tlb)->tlb_mtx), MA_NOTOWNED)
#define TCPID_BUCKET_REF(tlb) refcount_acquire(&((tlb)->tlb_refcnt))
#define TCPID_BUCKET_UNREF(tlb) refcount_release(&((tlb)->tlb_refcnt))
#define TCPLOG_EXPIREQ_LOCK() mtx_lock(&tcp_log_expireq_mtx)
#define TCPLOG_EXPIREQ_UNLOCK() mtx_unlock(&tcp_log_expireq_mtx)
SLIST_HEAD(tcp_log_id_head, tcp_log_id_node);
struct tcp_log_id_bucket
{
/*
* tlb_id must be first. This lets us use strcmp on
* (struct tcp_log_id_bucket *) and (char *) interchangeably.
*/
char tlb_id[TCP_LOG_ID_LEN];
char tlb_tag[TCP_LOG_TAG_LEN];
RB_ENTRY(tcp_log_id_bucket) tlb_rb;
struct tcp_log_id_head tlb_head;
struct mtx tlb_mtx;
volatile u_int tlb_refcnt;
volatile u_int tlb_reqcnt;
uint32_t tlb_loglimit;
uint8_t tlb_logstate;
};
struct tcp_log_id_node
{
SLIST_ENTRY(tcp_log_id_node) tln_list;
STAILQ_ENTRY(tcp_log_id_node) tln_expireq; /* Locked by the expireq lock */
sbintime_t tln_expiretime; /* Locked by the expireq lock */
/*
* If INP is NULL, that means the connection has closed. We've
* saved the connection endpoint information and the log entries
* in the tln_ie and tln_entries members. We've also saved a pointer
* to the enclosing bucket here. If INP is not NULL, the information is
* in the PCB and not here.
*/
struct inpcb *tln_inp;
struct tcpcb *tln_tp;
struct tcp_log_id_bucket *tln_bucket;
struct in_endpoints tln_ie;
struct tcp_log_stailq tln_entries;
int tln_count;
volatile int tln_closed;
uint8_t tln_af;
};
enum tree_lock_state {
TREE_UNLOCKED = 0,
TREE_RLOCKED,
TREE_WLOCKED,
};
/* Do we want to select this session for auto-logging? */
static __inline bool
tcp_log_selectauto(void)
{
/*
* If we are doing auto-capturing, figure out whether we will capture
* this session.
*/
if (tcp_log_auto_ratio &&
(tcp_disable_all_bb_logs == 0) &&
(atomic_fetchadd_long(&tcp_log_auto_ratio_cur, 1) %
tcp_log_auto_ratio) == 0)
return (true);
return (false);
}
static __inline int
tcp_log_id_cmp(struct tcp_log_id_bucket *a, struct tcp_log_id_bucket *b)
{
KASSERT(a != NULL, ("tcp_log_id_cmp: argument a is unexpectedly NULL"));
KASSERT(b != NULL, ("tcp_log_id_cmp: argument b is unexpectedly NULL"));
return strncmp(a->tlb_id, b->tlb_id, TCP_LOG_ID_LEN);
}
RB_GENERATE_STATIC(tcp_log_id_tree, tcp_log_id_bucket, tlb_rb, tcp_log_id_cmp)
static __inline void
tcp_log_id_validate_tree_lock(int tree_locked)
{
#ifdef INVARIANTS
switch (tree_locked) {
case TREE_WLOCKED:
TCPID_TREE_WLOCK_ASSERT();
break;
case TREE_RLOCKED:
TCPID_TREE_RLOCK_ASSERT();
break;
case TREE_UNLOCKED:
TCPID_TREE_UNLOCK_ASSERT();
break;
default:
kassert_panic("%s:%d: unknown tree lock state", __func__,
__LINE__);
}
#endif
}
static __inline void
tcp_log_remove_bucket(struct tcp_log_id_bucket *tlb)
{
TCPID_TREE_WLOCK_ASSERT();
KASSERT(SLIST_EMPTY(&tlb->tlb_head),
("%s: Attempt to remove non-empty bucket", __func__));
if (RB_REMOVE(tcp_log_id_tree, &tcp_log_id_head, tlb) == NULL) {
#ifdef INVARIANTS
kassert_panic("%s:%d: error removing element from tree",
__func__, __LINE__);
#endif
}
TCPID_BUCKET_LOCK_DESTROY(tlb);
counter_u64_add(tcp_log_pcb_ids_cur, (int64_t)-1);
uma_zfree(tcp_log_bucket_zone, tlb);
}
/*
* Call with a referenced and locked bucket.
* Will return true if the bucket was freed; otherwise, false.
* tlb: The bucket to unreference.
* tree_locked: A pointer to the state of the tree lock. If the tree lock
* state changes, the function will update it.
* inp: If not NULL and the function needs to drop the inp lock to relock the
* tree, it will do so. (The caller must ensure inp will not become invalid,
* probably by holding a reference to it.)
*/
static bool
tcp_log_unref_bucket(struct tcp_log_id_bucket *tlb, int *tree_locked,
struct inpcb *inp)
{
KASSERT(tlb != NULL, ("%s: called with NULL tlb", __func__));
KASSERT(tree_locked != NULL, ("%s: called with NULL tree_locked",
__func__));
tcp_log_id_validate_tree_lock(*tree_locked);
/*
* Did we hold the last reference on the tlb? If so, we may need
* to free it. (Note that we can realistically only execute the
* loop twice: once without a write lock and once with a write
* lock.)
*/
while (TCPID_BUCKET_UNREF(tlb)) {
/*
* We need a write lock on the tree to free this.
* If we can upgrade the tree lock, this is "easy". If we
* can't upgrade the tree lock, we need to do this the
* "hard" way: unwind all our locks and relock everything.
* In the meantime, anything could have changed. We even
* need to validate that we still need to free the bucket.
*/
if (*tree_locked == TREE_RLOCKED && TCPID_TREE_UPGRADE())
*tree_locked = TREE_WLOCKED;
else if (*tree_locked != TREE_WLOCKED) {
TCPID_BUCKET_REF(tlb);
if (inp != NULL)
INP_WUNLOCK(inp);
TCPID_BUCKET_UNLOCK(tlb);
if (*tree_locked == TREE_RLOCKED)
TCPID_TREE_RUNLOCK();
TCPID_TREE_WLOCK();
*tree_locked = TREE_WLOCKED;
TCPID_BUCKET_LOCK(tlb);
if (inp != NULL)
INP_WLOCK(inp);
continue;
}
/*
* We have an empty bucket and a write lock on the tree.
* Remove the empty bucket.
*/
tcp_log_remove_bucket(tlb);
return (true);
}
return (false);
}
/*
* Call with a locked bucket. This function will release the lock on the
* bucket before returning.
*
* The caller is responsible for freeing the tp->t_lin/tln node!
*
* Note: one of tp or both tlb and tln must be supplied.
*
* inp: A pointer to the inp. If the function needs to drop the inp lock to
* acquire the tree write lock, it will do so. (The caller must ensure inp
* will not become invalid, probably by holding a reference to it.)
* tp: A pointer to the tcpcb. (optional; if specified, tlb and tln are ignored)
* tlb: A pointer to the bucket. (optional; ignored if tp is specified)
* tln: A pointer to the node. (optional; ignored if tp is specified)
* tree_locked: A pointer to the state of the tree lock. If the tree lock
* state changes, the function will update it.
*
* Will return true if the INP lock was reacquired; otherwise, false.
*/
static bool
tcp_log_remove_id_node(struct inpcb *inp, struct tcpcb *tp,
struct tcp_log_id_bucket *tlb, struct tcp_log_id_node *tln,
int *tree_locked)
{
int orig_tree_locked;
KASSERT(tp != NULL || (tlb != NULL && tln != NULL),
("%s: called with tp=%p, tlb=%p, tln=%p", __func__,
tp, tlb, tln));
KASSERT(tree_locked != NULL, ("%s: called with NULL tree_locked",
__func__));
if (tp != NULL) {
tlb = tp->t_lib;
tln = tp->t_lin;
KASSERT(tlb != NULL, ("%s: unexpectedly NULL tlb", __func__));
KASSERT(tln != NULL, ("%s: unexpectedly NULL tln", __func__));
}
tcp_log_id_validate_tree_lock(*tree_locked);
TCPID_BUCKET_LOCK_ASSERT(tlb);
/*
* Remove the node, clear the log bucket and node from the TCPCB, and
* decrement the bucket refcount. In the process, if this is the
* last reference, the bucket will be freed.
*/
SLIST_REMOVE(&tlb->tlb_head, tln, tcp_log_id_node, tln_list);
if (tp != NULL) {
tp->t_lib = NULL;
tp->t_lin = NULL;
}
orig_tree_locked = *tree_locked;
if (!tcp_log_unref_bucket(tlb, tree_locked, inp))
TCPID_BUCKET_UNLOCK(tlb);
return (*tree_locked != orig_tree_locked);
}
#define RECHECK_INP_CLEAN(cleanup) do { \
if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) { \
rv = ECONNRESET; \
cleanup; \
goto done; \
} \
tp = intotcpcb(inp); \
} while (0)
#define RECHECK_INP() RECHECK_INP_CLEAN(/* noop */)
static void
tcp_log_grow_tlb(char *tlb_id, struct tcpcb *tp)
{
INP_WLOCK_ASSERT(tp->t_inpcb);
#ifdef STATS
if (V_tcp_perconn_stats_enable == 2 && tp->t_stats == NULL)
(void)tcp_stats_sample_rollthedice(tp, tlb_id, strlen(tlb_id));
#endif
}
static void
tcp_log_increment_reqcnt(struct tcp_log_id_bucket *tlb)
{
atomic_fetchadd_int(&tlb->tlb_reqcnt, 1);
}
/*
* Associate the specified tag with a particular TCP log ID.
* Called with INPCB locked. Returns with it unlocked.
* Returns 0 on success or EOPNOTSUPP if the connection has no TCP log ID.
*/
int
tcp_log_set_tag(struct tcpcb *tp, char *tag)
{
struct tcp_log_id_bucket *tlb;
int tree_locked;
INP_WLOCK_ASSERT(tp->t_inpcb);
tree_locked = TREE_UNLOCKED;
tlb = tp->t_lib;
if (tlb == NULL) {
INP_WUNLOCK(tp->t_inpcb);
return (EOPNOTSUPP);
}
TCPID_BUCKET_REF(tlb);
INP_WUNLOCK(tp->t_inpcb);
TCPID_BUCKET_LOCK(tlb);
strlcpy(tlb->tlb_tag, tag, TCP_LOG_TAG_LEN);
if (!tcp_log_unref_bucket(tlb, &tree_locked, NULL))
TCPID_BUCKET_UNLOCK(tlb);
if (tree_locked == TREE_WLOCKED) {
TCPID_TREE_WLOCK_ASSERT();
TCPID_TREE_WUNLOCK();
} else if (tree_locked == TREE_RLOCKED) {
TCPID_TREE_RLOCK_ASSERT();
TCPID_TREE_RUNLOCK();
} else
TCPID_TREE_UNLOCK_ASSERT();
return (0);
}
/*
* Set the TCP log ID for a TCPCB.
* Called with INPCB locked. Returns with it unlocked.
*/
int
tcp_log_set_id(struct tcpcb *tp, char *id)
{
struct tcp_log_id_bucket *tlb, *tmp_tlb;
struct tcp_log_id_node *tln;
struct inpcb *inp;
int tree_locked, rv;
bool bucket_locked;
tlb = NULL;
tln = NULL;
inp = tp->t_inpcb;
tree_locked = TREE_UNLOCKED;
bucket_locked = false;
restart:
INP_WLOCK_ASSERT(inp);
/* See if the ID is unchanged. */
if ((tp->t_lib != NULL && !strcmp(tp->t_lib->tlb_id, id)) ||
(tp->t_lib == NULL && *id == 0)) {
if (tp->t_lib != NULL) {
tcp_log_increment_reqcnt(tp->t_lib);
if ((tp->t_lib->tlb_logstate) &&
(tp->t_log_state_set == 0)) {
/* Clone in any logging */
tp->t_logstate = tp->t_lib->tlb_logstate;
}
if ((tp->t_lib->tlb_loglimit) &&
(tp->t_log_state_set == 0)) {
/* We also have a limit set */
tp->t_loglimit = tp->t_lib->tlb_loglimit;
}
}
rv = 0;
goto done;
}
/*
* If the TCPCB had a previous ID, we need to extricate it from
* the previous list.
*
* Drop the TCPCB lock and lock the tree and the bucket.
* Because this is called in the socket context, we (theoretically)
* don't need to worry about the INPCB completely going away
* while we are gone.
*/
if (tp->t_lib != NULL) {
tlb = tp->t_lib;
TCPID_BUCKET_REF(tlb);
INP_WUNLOCK(inp);
if (tree_locked == TREE_UNLOCKED) {
TCPID_TREE_RLOCK();
tree_locked = TREE_RLOCKED;
}
TCPID_BUCKET_LOCK(tlb);
bucket_locked = true;
INP_WLOCK(inp);
/*
* Unreference the bucket. If our bucket went away, it is no
* longer locked or valid.
*/
if (tcp_log_unref_bucket(tlb, &tree_locked, inp)) {
bucket_locked = false;
tlb = NULL;
}
/* Validate the INP. */
RECHECK_INP();
/*
* Evaluate whether the bucket changed while we were unlocked.
*
* Possible scenarios here:
* 1. Bucket is unchanged and the same one we started with.
* 2. The TCPCB no longer has a bucket and our bucket was
* freed.
* 3. The TCPCB has a new bucket, whether ours was freed.
* 4. The TCPCB no longer has a bucket and our bucket was
* not freed.
*
* In cases 2-4, we will start over. In case 1, we will
* proceed here to remove the bucket.
*/
if (tlb == NULL || tp->t_lib != tlb) {
KASSERT(bucket_locked || tlb == NULL,
("%s: bucket_locked (%d) and tlb (%p) are "
"inconsistent", __func__, bucket_locked, tlb));
if (bucket_locked) {
TCPID_BUCKET_UNLOCK(tlb);
bucket_locked = false;
tlb = NULL;
}
goto restart;
}
/*
* Store the (struct tcp_log_id_node) for reuse. Then, remove
* it from the bucket. In the process, we may end up relocking.
* If so, we need to validate that the INP is still valid, and
* the TCPCB entries match we expect.
*
* We will clear tlb and change the bucket_locked state just
* before calling tcp_log_remove_id_node(), since that function
* will unlock the bucket.
*/
if (tln != NULL)
uma_zfree(tcp_log_node_zone, tln);
tln = tp->t_lin;
tlb = NULL;
bucket_locked = false;
if (tcp_log_remove_id_node(inp, tp, NULL, NULL, &tree_locked)) {
RECHECK_INP();
/*
* If the TCPCB moved to a new bucket while we had
* dropped the lock, restart.
*/
if (tp->t_lib != NULL || tp->t_lin != NULL)
goto restart;
}
/*
* Yay! We successfully removed the TCPCB from its old
* bucket. Phew!
*
* On to bigger and better things...
*/
}
/* At this point, the TCPCB should not be in any bucket. */
KASSERT(tp->t_lib == NULL, ("%s: tp->t_lib is not NULL", __func__));
/*
* If the new ID is not empty, we need to now assign this TCPCB to a
* new bucket.
*/
if (*id) {
/* Get a new tln, if we don't already have one to reuse. */
if (tln == NULL) {
tln = uma_zalloc(tcp_log_node_zone, M_NOWAIT | M_ZERO);
if (tln == NULL) {
rv = ENOBUFS;
goto done;
}
tln->tln_inp = inp;
tln->tln_tp = tp;
}
/*
* Drop the INP lock for a bit. We don't need it, and dropping
* it prevents lock order reversals.
*/
INP_WUNLOCK(inp);
/* Make sure we have at least a read lock on the tree. */
tcp_log_id_validate_tree_lock(tree_locked);
if (tree_locked == TREE_UNLOCKED) {
TCPID_TREE_RLOCK();
tree_locked = TREE_RLOCKED;
}
refind:
/*
* Remember that we constructed (struct tcp_log_id_node) so
* we can safely cast the id to it for the purposes of finding.
*/
KASSERT(tlb == NULL, ("%s:%d tlb unexpectedly non-NULL",
__func__, __LINE__));
tmp_tlb = RB_FIND(tcp_log_id_tree, &tcp_log_id_head,
(struct tcp_log_id_bucket *) id);
/*
* If we didn't find a matching bucket, we need to add a new
* one. This requires a write lock. But, of course, we will
* need to recheck some things when we re-acquire the lock.
*/
if (tmp_tlb == NULL && tree_locked != TREE_WLOCKED) {
tree_locked = TREE_WLOCKED;
if (!TCPID_TREE_UPGRADE()) {
TCPID_TREE_RUNLOCK();
TCPID_TREE_WLOCK();
/*
* The tree may have changed while we were
* unlocked.
*/
goto refind;
}
}
/* If we need to add a new bucket, do it now. */
if (tmp_tlb == NULL) {
/* Allocate new bucket. */
tlb = uma_zalloc(tcp_log_bucket_zone, M_NOWAIT);
if (tlb == NULL) {
rv = ENOBUFS;
goto done_noinp;
}
counter_u64_add(tcp_log_pcb_ids_cur, 1);
counter_u64_add(tcp_log_pcb_ids_tot, 1);
if ((tcp_log_auto_all == false) &&
tcp_log_auto_mode &&
tcp_log_selectauto()) {
/* Save off the log state */
tlb->tlb_logstate = tcp_log_auto_mode;
} else
tlb->tlb_logstate = TCP_LOG_STATE_OFF;
tlb->tlb_loglimit = 0;
tlb->tlb_tag[0] = '\0'; /* Default to an empty tag. */
/*
* Copy the ID to the bucket.
* NB: Don't use strlcpy() unless you are sure
* we've always validated NULL termination.
*
* TODO: When I'm done writing this, see if we
* we have correctly validated NULL termination and
* can use strlcpy(). :-)
*/
strncpy(tlb->tlb_id, id, TCP_LOG_ID_LEN - 1);
tlb->tlb_id[TCP_LOG_ID_LEN - 1] = '\0';
/*
* Take the refcount for the first node and go ahead
* and lock this. Note that we zero the tlb_mtx
* structure, since 0xdeadc0de flips the right bits
* for the code to think that this mutex has already
* been initialized. :-(
*/
SLIST_INIT(&tlb->tlb_head);
refcount_init(&tlb->tlb_refcnt, 1);
tlb->tlb_reqcnt = 1;
memset(&tlb->tlb_mtx, 0, sizeof(struct mtx));
TCPID_BUCKET_LOCK_INIT(tlb);
TCPID_BUCKET_LOCK(tlb);
bucket_locked = true;
#define FREE_NEW_TLB() do { \
TCPID_BUCKET_LOCK_DESTROY(tlb); \
uma_zfree(tcp_log_bucket_zone, tlb); \
counter_u64_add(tcp_log_pcb_ids_cur, (int64_t)-1); \
counter_u64_add(tcp_log_pcb_ids_tot, (int64_t)-1); \
bucket_locked = false; \
tlb = NULL; \
} while (0)
/*
* Relock the INP and make sure we are still
* unassigned.
*/
INP_WLOCK(inp);
RECHECK_INP_CLEAN(FREE_NEW_TLB());
if (tp->t_lib != NULL) {
FREE_NEW_TLB();
goto restart;
}
/* Add the new bucket to the tree. */
tmp_tlb = RB_INSERT(tcp_log_id_tree, &tcp_log_id_head,
tlb);
KASSERT(tmp_tlb == NULL,
("%s: Unexpected conflicting bucket (%p) while "
"adding new bucket (%p)", __func__, tmp_tlb, tlb));
/*
* If we found a conflicting bucket, free the new
* one we made and fall through to use the existing
* bucket.
*/
if (tmp_tlb != NULL) {
FREE_NEW_TLB();
INP_WUNLOCK(inp);
}
#undef FREE_NEW_TLB
}
/* If we found an existing bucket, use it. */
if (tmp_tlb != NULL) {
tlb = tmp_tlb;
TCPID_BUCKET_LOCK(tlb);
bucket_locked = true;
/*
* Relock the INP and make sure we are still
* unassigned.
*/
INP_UNLOCK_ASSERT(inp);
INP_WLOCK(inp);
RECHECK_INP();
if (tp->t_lib != NULL) {
TCPID_BUCKET_UNLOCK(tlb);
bucket_locked = false;
tlb = NULL;
goto restart;
}
/* Take a reference on the bucket. */
TCPID_BUCKET_REF(tlb);
/* Record the request. */
tcp_log_increment_reqcnt(tlb);
}
tcp_log_grow_tlb(tlb->tlb_id, tp);
/* Add the new node to the list. */
SLIST_INSERT_HEAD(&tlb->tlb_head, tln, tln_list);
tp->t_lib = tlb;
tp->t_lin = tln;
if (tp->t_lib->tlb_logstate) {
/* Clone in any logging */
tp->t_logstate = tp->t_lib->tlb_logstate;
}
if (tp->t_lib->tlb_loglimit) {
/* The loglimit too */
tp->t_loglimit = tp->t_lib->tlb_loglimit;
}
tln = NULL;
}
rv = 0;
done:
/* Unlock things, as needed, and return. */
INP_WUNLOCK(inp);
done_noinp:
INP_UNLOCK_ASSERT(inp);
if (bucket_locked) {
TCPID_BUCKET_LOCK_ASSERT(tlb);
TCPID_BUCKET_UNLOCK(tlb);
} else if (tlb != NULL)
TCPID_BUCKET_UNLOCK_ASSERT(tlb);
if (tree_locked == TREE_WLOCKED) {
TCPID_TREE_WLOCK_ASSERT();
TCPID_TREE_WUNLOCK();
} else if (tree_locked == TREE_RLOCKED) {
TCPID_TREE_RLOCK_ASSERT();
TCPID_TREE_RUNLOCK();
} else
TCPID_TREE_UNLOCK_ASSERT();
if (tln != NULL)
uma_zfree(tcp_log_node_zone, tln);
return (rv);
}
/*
* Get the TCP log ID for a TCPCB.
* Called with INPCB locked.
* 'buf' must point to a buffer that is at least TCP_LOG_ID_LEN bytes long.
* Returns number of bytes copied.
*/
size_t
tcp_log_get_id(struct tcpcb *tp, char *buf)
{
size_t len;
INP_LOCK_ASSERT(tp->t_inpcb);
if (tp->t_lib != NULL) {
len = strlcpy(buf, tp->t_lib->tlb_id, TCP_LOG_ID_LEN);
KASSERT(len < TCP_LOG_ID_LEN,
("%s:%d: tp->t_lib->tlb_id too long (%zu)",
__func__, __LINE__, len));
} else {
*buf = '\0';
len = 0;
}
return (len);
}
/*
* Get the tag associated with the TCPCB's log ID.
* Called with INPCB locked. Returns with it unlocked.
* 'buf' must point to a buffer that is at least TCP_LOG_TAG_LEN bytes long.
* Returns number of bytes copied.
*/
size_t
tcp_log_get_tag(struct tcpcb *tp, char *buf)
{
struct tcp_log_id_bucket *tlb;
size_t len;
int tree_locked;
INP_WLOCK_ASSERT(tp->t_inpcb);
tree_locked = TREE_UNLOCKED;
tlb = tp->t_lib;
if (tlb != NULL) {
TCPID_BUCKET_REF(tlb);
INP_WUNLOCK(tp->t_inpcb);
TCPID_BUCKET_LOCK(tlb);
len = strlcpy(buf, tlb->tlb_tag, TCP_LOG_TAG_LEN);
KASSERT(len < TCP_LOG_TAG_LEN,
("%s:%d: tp->t_lib->tlb_tag too long (%zu)",
__func__, __LINE__, len));
if (!tcp_log_unref_bucket(tlb, &tree_locked, NULL))
TCPID_BUCKET_UNLOCK(tlb);
if (tree_locked == TREE_WLOCKED) {
TCPID_TREE_WLOCK_ASSERT();
TCPID_TREE_WUNLOCK();
} else if (tree_locked == TREE_RLOCKED) {
TCPID_TREE_RLOCK_ASSERT();
TCPID_TREE_RUNLOCK();
} else
TCPID_TREE_UNLOCK_ASSERT();
} else {
INP_WUNLOCK(tp->t_inpcb);
*buf = '\0';
len = 0;
}
return (len);
}
/*
* Get number of connections with the same log ID.
* Log ID is taken from given TCPCB.
* Called with INPCB locked.
*/
u_int
tcp_log_get_id_cnt(struct tcpcb *tp)
{
INP_WLOCK_ASSERT(tp->t_inpcb);
return ((tp->t_lib == NULL) ? 0 : tp->t_lib->tlb_refcnt);
}
#ifdef TCPLOG_DEBUG_RINGBUF
/*
* Functions/macros to increment/decrement reference count for a log
* entry. This should catch when we do a double-free/double-remove or
* a double-add.
*/
static inline void
_tcp_log_entry_refcnt_add(struct tcp_log_mem *log_entry, const char *func,
int line)
{
int refcnt;
refcnt = atomic_fetchadd_int(&log_entry->tlm_refcnt, 1);
if (refcnt != 0)
panic("%s:%d: log_entry(%p)->tlm_refcnt is %d (expected 0)",
func, line, log_entry, refcnt);
}
#define tcp_log_entry_refcnt_add(l) \
_tcp_log_entry_refcnt_add((l), __func__, __LINE__)
static inline void
_tcp_log_entry_refcnt_rem(struct tcp_log_mem *log_entry, const char *func,
int line)
{
int refcnt;
refcnt = atomic_fetchadd_int(&log_entry->tlm_refcnt, -1);
if (refcnt != 1)
panic("%s:%d: log_entry(%p)->tlm_refcnt is %d (expected 1)",
func, line, log_entry, refcnt);
}
#define tcp_log_entry_refcnt_rem(l) \
_tcp_log_entry_refcnt_rem((l), __func__, __LINE__)
#else /* !TCPLOG_DEBUG_RINGBUF */
#define tcp_log_entry_refcnt_add(l)
#define tcp_log_entry_refcnt_rem(l)
#endif
/*
* Cleanup after removing a log entry, but only decrement the count if we
* are running INVARIANTS.
*/
static inline void
tcp_log_free_log_common(struct tcp_log_mem *log_entry, int *count __unused)
{
uma_zfree(tcp_log_zone, log_entry);
#ifdef INVARIANTS
(*count)--;
KASSERT(*count >= 0,
("%s: count unexpectedly negative", __func__));
#endif
}
static void
tcp_log_free_entries(struct tcp_log_stailq *head, int *count)
{
struct tcp_log_mem *log_entry;
/* Free the entries. */
while ((log_entry = STAILQ_FIRST(head)) != NULL) {
STAILQ_REMOVE_HEAD(head, tlm_queue);
tcp_log_entry_refcnt_rem(log_entry);
tcp_log_free_log_common(log_entry, count);
}
}
/* Cleanup after removing a log entry. */
static inline void
tcp_log_remove_log_cleanup(struct tcpcb *tp, struct tcp_log_mem *log_entry)
{
uma_zfree(tcp_log_zone, log_entry);
tp->t_lognum--;
KASSERT(tp->t_lognum >= 0,
("%s: tp->t_lognum unexpectedly negative", __func__));
}
/* Remove a log entry from the head of a list. */
static inline void
tcp_log_remove_log_head(struct tcpcb *tp, struct tcp_log_mem *log_entry)
{
KASSERT(log_entry == STAILQ_FIRST(&tp->t_logs),
("%s: attempt to remove non-HEAD log entry", __func__));
STAILQ_REMOVE_HEAD(&tp->t_logs, tlm_queue);
tcp_log_entry_refcnt_rem(log_entry);
tcp_log_remove_log_cleanup(tp, log_entry);
}
#ifdef TCPLOG_DEBUG_RINGBUF
/*
* Initialize the log entry's reference count, which we want to
* survive allocations.
*/
static int
tcp_log_zone_init(void *mem, int size, int flags __unused)
{
struct tcp_log_mem *tlm;
KASSERT(size >= sizeof(struct tcp_log_mem),
("%s: unexpectedly short (%d) allocation", __func__, size));
tlm = (struct tcp_log_mem *)mem;
tlm->tlm_refcnt = 0;
return (0);
}
/*
* Double check that the refcnt is zero on allocation and return.
*/
static int
tcp_log_zone_ctor(void *mem, int size, void *args __unused, int flags __unused)
{
struct tcp_log_mem *tlm;
KASSERT(size >= sizeof(struct tcp_log_mem),
("%s: unexpectedly short (%d) allocation", __func__, size));
tlm = (struct tcp_log_mem *)mem;
if (tlm->tlm_refcnt != 0)
panic("%s:%d: tlm(%p)->tlm_refcnt is %d (expected 0)",
__func__, __LINE__, tlm, tlm->tlm_refcnt);
return (0);
}
static void
tcp_log_zone_dtor(void *mem, int size, void *args __unused)
{
struct tcp_log_mem *tlm;
KASSERT(size >= sizeof(struct tcp_log_mem),
("%s: unexpectedly short (%d) allocation", __func__, size));
tlm = (struct tcp_log_mem *)mem;
if (tlm->tlm_refcnt != 0)
panic("%s:%d: tlm(%p)->tlm_refcnt is %d (expected 0)",
__func__, __LINE__, tlm, tlm->tlm_refcnt);
}
#endif /* TCPLOG_DEBUG_RINGBUF */
/* Do global initialization. */
void
tcp_log_init(void)
{
tcp_log_zone = uma_zcreate("tcp_log", sizeof(struct tcp_log_mem),
#ifdef TCPLOG_DEBUG_RINGBUF
tcp_log_zone_ctor, tcp_log_zone_dtor, tcp_log_zone_init,
#else
NULL, NULL, NULL,
#endif
NULL, UMA_ALIGN_PTR, 0);
(void)uma_zone_set_max(tcp_log_zone, TCP_LOG_BUF_DEFAULT_GLOBAL_LIMIT);
tcp_log_bucket_zone = uma_zcreate("tcp_log_bucket",
sizeof(struct tcp_log_id_bucket), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
tcp_log_node_zone = uma_zcreate("tcp_log_node",
sizeof(struct tcp_log_id_node), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
#ifdef TCPLOG_DEBUG_COUNTERS
tcp_log_queued = counter_u64_alloc(M_WAITOK);
tcp_log_que_fail1 = counter_u64_alloc(M_WAITOK);
tcp_log_que_fail2 = counter_u64_alloc(M_WAITOK);
tcp_log_que_fail3 = counter_u64_alloc(M_WAITOK);
tcp_log_que_fail4 = counter_u64_alloc(M_WAITOK);
tcp_log_que_fail5 = counter_u64_alloc(M_WAITOK);
tcp_log_que_copyout = counter_u64_alloc(M_WAITOK);
tcp_log_que_read = counter_u64_alloc(M_WAITOK);
tcp_log_que_freed = counter_u64_alloc(M_WAITOK);
#endif
tcp_log_pcb_ids_cur = counter_u64_alloc(M_WAITOK);
tcp_log_pcb_ids_tot = counter_u64_alloc(M_WAITOK);
rw_init_flags(&tcp_id_tree_lock, "TCP ID tree", RW_NEW);
mtx_init(&tcp_log_expireq_mtx, "TCP log expireq", NULL, MTX_DEF);
callout_init(&tcp_log_expireq_callout, 1);
}
/* Do per-TCPCB initialization. */
void
tcp_log_tcpcbinit(struct tcpcb *tp)
{
/* A new TCPCB should start out zero-initialized. */
STAILQ_INIT(&tp->t_logs);
/*
* If we are doing auto-capturing, figure out whether we will capture
* this session.
*/
tp->t_loglimit = tcp_log_session_limit;
if ((tcp_log_auto_all == true) &&
tcp_log_auto_mode &&
tcp_log_selectauto()) {
tp->t_logstate = tcp_log_auto_mode;
tp->t_flags2 |= TF2_LOG_AUTO;
}
}
/* Remove entries */
static void
tcp_log_expire(void *unused __unused)
{
struct tcp_log_id_bucket *tlb;
struct tcp_log_id_node *tln;
sbintime_t expiry_limit;
int tree_locked;
TCPLOG_EXPIREQ_LOCK();
if (callout_pending(&tcp_log_expireq_callout)) {
/* Callout was reset. */
TCPLOG_EXPIREQ_UNLOCK();
return;
}
/*
* Process entries until we reach one that expires too far in the
* future. Look one second in the future.
*/
expiry_limit = getsbinuptime() + SBT_1S;
tree_locked = TREE_UNLOCKED;
while ((tln = STAILQ_FIRST(&tcp_log_expireq_head)) != NULL &&
tln->tln_expiretime <= expiry_limit) {
if (!callout_active(&tcp_log_expireq_callout)) {
/*
* Callout was stopped. I guess we should
* just quit at this point.
*/
TCPLOG_EXPIREQ_UNLOCK();
return;
}
/*
* Remove the node from the head of the list and unlock
* the list. Change the expiry time to SBT_MAX as a signal
* to other threads that we now own this.
*/
STAILQ_REMOVE_HEAD(&tcp_log_expireq_head, tln_expireq);
tln->tln_expiretime = SBT_MAX;
TCPLOG_EXPIREQ_UNLOCK();
/*
* Remove the node from the bucket.
*/
tlb = tln->tln_bucket;
TCPID_BUCKET_LOCK(tlb);
if (tcp_log_remove_id_node(NULL, NULL, tlb, tln, &tree_locked)) {
tcp_log_id_validate_tree_lock(tree_locked);
if (tree_locked == TREE_WLOCKED)
TCPID_TREE_WUNLOCK();
else
TCPID_TREE_RUNLOCK();
tree_locked = TREE_UNLOCKED;
}
/* Drop the INP reference. */
INP_WLOCK(tln->tln_inp);
if (!in_pcbrele_wlocked(tln->tln_inp))
INP_WUNLOCK(tln->tln_inp);
/* Free the log records. */
tcp_log_free_entries(&tln->tln_entries, &tln->tln_count);
/* Free the node. */
uma_zfree(tcp_log_node_zone, tln);
/* Relock the expiry queue. */
TCPLOG_EXPIREQ_LOCK();
}
/*
* We've expired all the entries we can. Do we need to reschedule
* ourselves?
*/
callout_deactivate(&tcp_log_expireq_callout);
if (tln != NULL) {
/*
* Get max(now + TCP_LOG_EXPIRE_INTVL, tln->tln_expiretime) and
* set the next callout to that. (This helps ensure we generally
* run the callout no more often than desired.)
*/
expiry_limit = getsbinuptime() + TCP_LOG_EXPIRE_INTVL;
if (expiry_limit < tln->tln_expiretime)
expiry_limit = tln->tln_expiretime;
callout_reset_sbt(&tcp_log_expireq_callout, expiry_limit,
SBT_1S, tcp_log_expire, NULL, C_ABSOLUTE);
}
/* We're done. */
TCPLOG_EXPIREQ_UNLOCK();
return;
}
/*
* Move log data from the TCPCB to a new node. This will reset the TCPCB log
* entries and log count; however, it will not touch other things from the
* TCPCB (e.g. t_lin, t_lib).
*
* NOTE: Must hold a lock on the INP.
*/
static void
tcp_log_move_tp_to_node(struct tcpcb *tp, struct tcp_log_id_node *tln)
{
INP_WLOCK_ASSERT(tp->t_inpcb);
tln->tln_ie = tp->t_inpcb->inp_inc.inc_ie;
if (tp->t_inpcb->inp_inc.inc_flags & INC_ISIPV6)
tln->tln_af = AF_INET6;
else
tln->tln_af = AF_INET;
tln->tln_entries = tp->t_logs;
tln->tln_count = tp->t_lognum;
tln->tln_bucket = tp->t_lib;
/* Clear information from the PCB. */
STAILQ_INIT(&tp->t_logs);
tp->t_lognum = 0;
}
/* Do per-TCPCB cleanup */
void
tcp_log_tcpcbfini(struct tcpcb *tp)
{
struct tcp_log_id_node *tln, *tln_first;
struct tcp_log_mem *log_entry;
sbintime_t callouttime;
INP_WLOCK_ASSERT(tp->t_inpcb);
TCP_LOG_EVENT(tp, NULL, NULL, NULL, TCP_LOG_CONNEND, 0, 0, NULL, false);
/*
* If we were gathering packets to be automatically dumped, try to do
* it now. If this succeeds, the log information in the TCPCB will be
* cleared. Otherwise, we'll handle the log information as we do
* for other states.
*/
switch(tp->t_logstate) {
case TCP_LOG_STATE_HEAD_AUTO:
(void)tcp_log_dump_tp_logbuf(tp, "auto-dumped from head",
M_NOWAIT, false);
break;
case TCP_LOG_STATE_TAIL_AUTO:
(void)tcp_log_dump_tp_logbuf(tp, "auto-dumped from tail",
M_NOWAIT, false);
break;
case TCP_LOG_STATE_CONTINUAL:
(void)tcp_log_dump_tp_logbuf(tp, "auto-dumped from continual",
M_NOWAIT, false);
break;
}
/*
* There are two ways we could keep logs: per-socket or per-ID. If
* we are tracking logs with an ID, then the logs survive the
* destruction of the TCPCB.
*
* If the TCPCB is associated with an ID node, move the logs from the
* TCPCB to the ID node. In theory, this is safe, for reasons which I
* will now explain for my own benefit when I next need to figure out
* this code. :-)
*
* We own the INP lock. Therefore, no one else can change the contents
* of this node (Rule C). Further, no one can remove this node from
* the bucket while we hold the lock (Rule D). Basically, no one can
* mess with this node. That leaves two states in which we could be:
*
* 1. Another thread is currently waiting to acquire the INP lock, with
* plans to do something with this node. When we drop the INP lock,
* they will have a chance to do that. They will recheck the
* tln_closed field (see note to Rule C) and then acquire the
* bucket lock before proceeding further.
*
* 2. Another thread will try to acquire a lock at some point in the
* future. If they try to acquire a lock before we set the
* tln_closed field, they will follow state #1. If they try to
* acquire a lock after we set the tln_closed field, they will be
* able to make changes to the node, at will, following Rule C.
*
* Therefore, we currently own this node and can make any changes
* we want. But, as soon as we set the tln_closed field to true, we
* have effectively dropped our lock on the node. (For this reason, we
* also need to make sure our writes are ordered correctly. An atomic
* operation with "release" semantics should be sufficient.)
*/
if (tp->t_lin != NULL) {
/* Copy the relevant information to the log entry. */
tln = tp->t_lin;
KASSERT(tln->tln_inp == tp->t_inpcb,
("%s: Mismatched inp (tln->tln_inp=%p, tp->t_inpcb=%p)",
__func__, tln->tln_inp, tp->t_inpcb));
tcp_log_move_tp_to_node(tp, tln);
/* Clear information from the PCB. */
tp->t_lin = NULL;
tp->t_lib = NULL;
/*
* Take a reference on the INP. This ensures that the INP
* remains valid while the node is on the expiry queue. This
* ensures the INP is valid for other threads that may be
* racing to lock this node when we move it to the expire
* queue.
*/
in_pcbref(tp->t_inpcb);
/*
* Store the entry on the expiry list. The exact behavior
* depends on whether we have entries to keep. If so, we
* put the entry at the tail of the list and expire in
* TCP_LOG_EXPIRE_TIME. Otherwise, we expire "now" and put
* the entry at the head of the list. (Handling the cleanup
* via the expiry timer lets us avoid locking messy-ness here.)
*/
tln->tln_expiretime = getsbinuptime();
TCPLOG_EXPIREQ_LOCK();
if (tln->tln_count) {
tln->tln_expiretime += TCP_LOG_EXPIRE_TIME;
if (STAILQ_EMPTY(&tcp_log_expireq_head) &&
!callout_active(&tcp_log_expireq_callout)) {
/*
* We are adding the first entry and a callout
* is not currently scheduled; therefore, we
* need to schedule one.
*/
callout_reset_sbt(&tcp_log_expireq_callout,
tln->tln_expiretime, SBT_1S, tcp_log_expire,
NULL, C_ABSOLUTE);
}
STAILQ_INSERT_TAIL(&tcp_log_expireq_head, tln,
tln_expireq);
} else {
callouttime = tln->tln_expiretime +
TCP_LOG_EXPIRE_INTVL;
tln_first = STAILQ_FIRST(&tcp_log_expireq_head);
if ((tln_first == NULL ||
callouttime < tln_first->tln_expiretime) &&
(callout_pending(&tcp_log_expireq_callout) ||
!callout_active(&tcp_log_expireq_callout))) {
/*
* The list is empty, or we want to run the
* expire code before the first entry's timer
* fires. Also, we are in a case where a callout
* is not actively running. We want to reset
* the callout to occur sooner.
*/
callout_reset_sbt(&tcp_log_expireq_callout,
callouttime, SBT_1S, tcp_log_expire, NULL,
C_ABSOLUTE);
}
/*
* Insert to the head, or just after the head, as
* appropriate. (This might result in small
* mis-orderings as a bunch of "expire now" entries
* gather at the start of the list, but that should
* not produce big problems, since the expire timer
* will walk through all of them.)
*/
if (tln_first == NULL ||
tln->tln_expiretime < tln_first->tln_expiretime)
STAILQ_INSERT_HEAD(&tcp_log_expireq_head, tln,
tln_expireq);
else
STAILQ_INSERT_AFTER(&tcp_log_expireq_head,
tln_first, tln, tln_expireq);
}
TCPLOG_EXPIREQ_UNLOCK();
/*
* We are done messing with the tln. After this point, we
* can't touch it. (Note that the "release" semantics should
* be included with the TCPLOG_EXPIREQ_UNLOCK() call above.
* Therefore, they should be unnecessary here. However, it
* seems like a good idea to include them anyway, since we
* really are releasing a lock here.)
*/
atomic_store_rel_int(&tln->tln_closed, 1);
} else {
/* Remove log entries. */
while ((log_entry = STAILQ_FIRST(&tp->t_logs)) != NULL)
tcp_log_remove_log_head(tp, log_entry);
KASSERT(tp->t_lognum == 0,
("%s: After freeing entries, tp->t_lognum=%d (expected 0)",
__func__, tp->t_lognum));
}
/*
* Change the log state to off (just in case anything tries to sneak
* in a last-minute log).
*/
tp->t_logstate = TCP_LOG_STATE_OFF;
}
static void
tcp_log_purge_tp_logbuf(struct tcpcb *tp)
{
struct tcp_log_mem *log_entry;
struct inpcb *inp;
inp = tp->t_inpcb;
INP_WLOCK_ASSERT(inp);
if (tp->t_lognum == 0)
return;
while ((log_entry = STAILQ_FIRST(&tp->t_logs)) != NULL)
tcp_log_remove_log_head(tp, log_entry);
KASSERT(tp->t_lognum == 0,
("%s: After freeing entries, tp->t_lognum=%d (expected 0)",
__func__, tp->t_lognum));
tp->t_logstate = TCP_LOG_STATE_OFF;
}
/*
* This logs an event for a TCP socket. Normally, this is called via
* TCP_LOG_EVENT or TCP_LOG_EVENT_VERBOSE. See the documentation for
* TCP_LOG_EVENT().
*/
struct tcp_log_buffer *
tcp_log_event_(struct tcpcb *tp, struct tcphdr *th, struct sockbuf *rxbuf,
struct sockbuf *txbuf, uint8_t eventid, int errornum, uint32_t len,
union tcp_log_stackspecific *stackinfo, int th_hostorder,
const char *output_caller, const char *func, int line, const struct timeval *itv)
{
struct tcp_log_mem *log_entry;
struct tcp_log_buffer *log_buf;
int attempt_count = 0;
struct tcp_log_verbose *log_verbose;
uint32_t logsn;
KASSERT((func == NULL && line == 0) || (func != NULL && line > 0),
("%s called with inconsistent func (%p) and line (%d) arguments",
__func__, func, line));
INP_WLOCK_ASSERT(tp->t_inpcb);
if (tcp_disable_all_bb_logs) {
/*
* The global shutdown logging
* switch has been thrown. Call
* the purge function that frees
* purges out the logs and
* turns off logging.
*/
tcp_log_purge_tp_logbuf(tp);
return (NULL);
}
KASSERT(tp->t_logstate == TCP_LOG_STATE_HEAD ||
tp->t_logstate == TCP_LOG_STATE_TAIL ||
tp->t_logstate == TCP_LOG_STATE_CONTINUAL ||
tp->t_logstate == TCP_LOG_STATE_HEAD_AUTO ||
tp->t_logstate == TCP_LOG_STATE_TAIL_AUTO,
("%s called with unexpected tp->t_logstate (%d)", __func__,
tp->t_logstate));
/*
* Get the serial number. We do this early so it will
* increment even if we end up skipping the log entry for some
* reason.
*/
logsn = tp->t_logsn++;
/*
* Can we get a new log entry? If so, increment the lognum counter
* here.
*/
retry:
if (tp->t_lognum < tp->t_loglimit) {
if ((log_entry = uma_zalloc(tcp_log_zone, M_NOWAIT)) != NULL)
tp->t_lognum++;
} else
log_entry = NULL;
/* Do we need to try to reuse? */
if (log_entry == NULL) {
/*
* Sacrifice auto-logged sessions without a log ID if
* tcp_log_auto_all is false. (If they don't have a log
* ID by now, it is probable that either they won't get one
* or we are resource-constrained.)
*/
if (tp->t_lib == NULL && (tp->t_flags2 & TF2_LOG_AUTO) &&
!tcp_log_auto_all) {
if (tcp_log_state_change(tp, TCP_LOG_STATE_CLEAR)) {
#ifdef INVARIANTS
panic("%s:%d: tcp_log_state_change() failed "
"to set tp %p to TCP_LOG_STATE_CLEAR",
__func__, __LINE__, tp);
#endif
tp->t_logstate = TCP_LOG_STATE_OFF;
}
return (NULL);
}
/*
* If we are in TCP_LOG_STATE_HEAD_AUTO state, try to dump
* the buffers. If successful, deactivate tracing. Otherwise,
* leave it active so we will retry.
*/
if (tp->t_logstate == TCP_LOG_STATE_HEAD_AUTO &&
!tcp_log_dump_tp_logbuf(tp, "auto-dumped from head",
M_NOWAIT, false)) {
tp->t_logstate = TCP_LOG_STATE_OFF;
return(NULL);
} else if ((tp->t_logstate == TCP_LOG_STATE_CONTINUAL) &&
!tcp_log_dump_tp_logbuf(tp, "auto-dumped from continual",
M_NOWAIT, false)) {
if (attempt_count == 0) {
attempt_count++;
goto retry;
}
#ifdef TCPLOG_DEBUG_COUNTERS
counter_u64_add(tcp_log_que_fail4, 1);
#endif
return(NULL);
} else if (tp->t_logstate == TCP_LOG_STATE_HEAD_AUTO)
return(NULL);
/* If in HEAD state, just deactivate the tracing and return. */
if (tp->t_logstate == TCP_LOG_STATE_HEAD) {
tp->t_logstate = TCP_LOG_STATE_OFF;
return(NULL);
}
/*
* Get a buffer to reuse. If that fails, just give up.
* (We can't log anything without a buffer in which to
* put it.)
*
* Note that we don't change the t_lognum counter
* here. Because we are re-using the buffer, the total
* number won't change.
*/
if ((log_entry = STAILQ_FIRST(&tp->t_logs)) == NULL)
return(NULL);
STAILQ_REMOVE_HEAD(&tp->t_logs, tlm_queue);
tcp_log_entry_refcnt_rem(log_entry);
}
KASSERT(log_entry != NULL,
("%s: log_entry unexpectedly NULL", __func__));
/* Extract the log buffer and verbose buffer pointers. */
log_buf = &log_entry->tlm_buf;
log_verbose = &log_entry->tlm_v;
/* Basic entries. */
if (itv == NULL)
getmicrouptime(&log_buf->tlb_tv);
else
memcpy(&log_buf->tlb_tv, itv, sizeof(struct timeval));
log_buf->tlb_ticks = ticks;
log_buf->tlb_sn = logsn;
log_buf->tlb_stackid = tp->t_fb->tfb_id;
log_buf->tlb_eventid = eventid;
log_buf->tlb_eventflags = 0;
log_buf->tlb_errno = errornum;
/* Socket buffers */
if (rxbuf != NULL) {
log_buf->tlb_eventflags |= TLB_FLAG_RXBUF;
log_buf->tlb_rxbuf.tls_sb_acc = rxbuf->sb_acc;
log_buf->tlb_rxbuf.tls_sb_ccc = rxbuf->sb_ccc;
log_buf->tlb_rxbuf.tls_sb_spare = 0;
}
if (txbuf != NULL) {
log_buf->tlb_eventflags |= TLB_FLAG_TXBUF;
log_buf->tlb_txbuf.tls_sb_acc = txbuf->sb_acc;
log_buf->tlb_txbuf.tls_sb_ccc = txbuf->sb_ccc;
log_buf->tlb_txbuf.tls_sb_spare = 0;
}
/* Copy values from tp to the log entry. */
#define COPY_STAT(f) log_buf->tlb_ ## f = tp->f
#define COPY_STAT_T(f) log_buf->tlb_ ## f = tp->t_ ## f
COPY_STAT_T(state);
COPY_STAT_T(starttime);
COPY_STAT(iss);
COPY_STAT_T(flags);
COPY_STAT(snd_una);
COPY_STAT(snd_max);
COPY_STAT(snd_cwnd);
COPY_STAT(snd_nxt);
COPY_STAT(snd_recover);
COPY_STAT(snd_wnd);
COPY_STAT(snd_ssthresh);
COPY_STAT_T(srtt);
COPY_STAT_T(rttvar);
COPY_STAT(rcv_up);
COPY_STAT(rcv_adv);
COPY_STAT(rcv_nxt);
COPY_STAT(rcv_wnd);
COPY_STAT_T(dupacks);
COPY_STAT_T(segqlen);
COPY_STAT(snd_numholes);
COPY_STAT(snd_scale);
COPY_STAT(rcv_scale);
COPY_STAT_T(flags2);
COPY_STAT_T(fbyte_in);
COPY_STAT_T(fbyte_out);
#undef COPY_STAT
#undef COPY_STAT_T
log_buf->tlb_flex1 = 0;
log_buf->tlb_flex2 = 0;
/* Copy stack-specific info. */
if (stackinfo != NULL) {
memcpy(&log_buf->tlb_stackinfo, stackinfo,
sizeof(log_buf->tlb_stackinfo));
log_buf->tlb_eventflags |= TLB_FLAG_STACKINFO;
}
/* The packet */
log_buf->tlb_len = len;
if (th) {
int optlen;
log_buf->tlb_eventflags |= TLB_FLAG_HDR;
log_buf->tlb_th = *th;
if (th_hostorder)
tcp_fields_to_net(&log_buf->tlb_th);
optlen = (th->th_off << 2) - sizeof (struct tcphdr);
if (optlen > 0)
memcpy(log_buf->tlb_opts, th + 1, optlen);
}
/* Verbose information */
if (func != NULL) {
log_buf->tlb_eventflags |= TLB_FLAG_VERBOSE;
if (output_caller != NULL)
strlcpy(log_verbose->tlv_snd_frm, output_caller,
TCP_FUNC_LEN);
else
*log_verbose->tlv_snd_frm = 0;
strlcpy(log_verbose->tlv_trace_func, func, TCP_FUNC_LEN);
log_verbose->tlv_trace_line = line;
}
/* Insert the new log at the tail. */
STAILQ_INSERT_TAIL(&tp->t_logs, log_entry, tlm_queue);
tcp_log_entry_refcnt_add(log_entry);
return (log_buf);
}
/*
* Change the logging state for a TCPCB. Returns 0 on success or an
* error code on failure.
*/
int
tcp_log_state_change(struct tcpcb *tp, int state)
{
struct tcp_log_mem *log_entry;
INP_WLOCK_ASSERT(tp->t_inpcb);
switch(state) {
case TCP_LOG_STATE_CLEAR:
while ((log_entry = STAILQ_FIRST(&tp->t_logs)) != NULL)
tcp_log_remove_log_head(tp, log_entry);
/* Fall through */
case TCP_LOG_STATE_OFF:
tp->t_logstate = TCP_LOG_STATE_OFF;
break;
case TCP_LOG_STATE_TAIL:
case TCP_LOG_STATE_HEAD:
case TCP_LOG_STATE_CONTINUAL:
case TCP_LOG_STATE_HEAD_AUTO:
case TCP_LOG_STATE_TAIL_AUTO:
tp->t_logstate = state;
break;
default:
return (EINVAL);
}
if (tcp_disable_all_bb_logs) {
/* We are prohibited from doing any logs */
tp->t_logstate = TCP_LOG_STATE_OFF;
}
tp->t_flags2 &= ~(TF2_LOG_AUTO);
return (0);
}
/* If tcp_drain() is called, flush half the log entries. */
void
tcp_log_drain(struct tcpcb *tp)
{
struct tcp_log_mem *log_entry, *next;
int target, skip;
INP_WLOCK_ASSERT(tp->t_inpcb);
if ((target = tp->t_lognum / 2) == 0)
return;
/*
* If we are logging the "head" packets, we want to discard
* from the tail of the queue. Otherwise, we want to discard
* from the head.
*/
if (tp->t_logstate == TCP_LOG_STATE_HEAD ||
tp->t_logstate == TCP_LOG_STATE_HEAD_AUTO) {
skip = tp->t_lognum - target;
STAILQ_FOREACH(log_entry, &tp->t_logs, tlm_queue)
if (!--skip)
break;
KASSERT(log_entry != NULL,
("%s: skipped through all entries!", __func__));
if (log_entry == NULL)
return;
while ((next = STAILQ_NEXT(log_entry, tlm_queue)) != NULL) {
STAILQ_REMOVE_AFTER(&tp->t_logs, log_entry, tlm_queue);
tcp_log_entry_refcnt_rem(next);
tcp_log_remove_log_cleanup(tp, next);
#ifdef INVARIANTS
target--;
#endif
}
KASSERT(target == 0,
("%s: After removing from tail, target was %d", __func__,
target));
} else if (tp->t_logstate == TCP_LOG_STATE_CONTINUAL) {
(void)tcp_log_dump_tp_logbuf(tp, "auto-dumped from continual",
M_NOWAIT, false);
} else {
while ((log_entry = STAILQ_FIRST(&tp->t_logs)) != NULL &&
target--)
tcp_log_remove_log_head(tp, log_entry);
KASSERT(target <= 0,
("%s: After removing from head, target was %d", __func__,
target));
KASSERT(tp->t_lognum > 0,
("%s: After removing from head, tp->t_lognum was %d",
__func__, target));
KASSERT(log_entry != NULL,
("%s: After removing from head, the tailq was empty",
__func__));
}
}
static inline int
tcp_log_copyout(struct sockopt *sopt, void *src, void *dst, size_t len)
{
if (sopt->sopt_td != NULL)
return (copyout(src, dst, len));
bcopy(src, dst, len);
return (0);
}
static int
tcp_log_logs_to_buf(struct sockopt *sopt, struct tcp_log_stailq *log_tailqp,
struct tcp_log_buffer **end, int count)
{
struct tcp_log_buffer *out_entry;
struct tcp_log_mem *log_entry;
size_t entrysize;
int error;
#ifdef INVARIANTS
int orig_count = count;
#endif
/* Copy the data out. */
error = 0;
out_entry = (struct tcp_log_buffer *) sopt->sopt_val;
STAILQ_FOREACH(log_entry, log_tailqp, tlm_queue) {
count--;
KASSERT(count >= 0,
("%s:%d: Exceeded expected count (%d) processing list %p",
__func__, __LINE__, orig_count, log_tailqp));
#ifdef TCPLOG_DEBUG_COUNTERS
counter_u64_add(tcp_log_que_copyout, 1);
#endif
/*
* Skip copying out the header if it isn't present.
* Instead, copy out zeros (to ensure we don't leak info).
* TODO: Make sure we truly do zero everything we don't
* explicitly set.
*/
if (log_entry->tlm_buf.tlb_eventflags & TLB_FLAG_HDR)
entrysize = sizeof(struct tcp_log_buffer);
else
entrysize = offsetof(struct tcp_log_buffer, tlb_th);
error = tcp_log_copyout(sopt, &log_entry->tlm_buf, out_entry,
entrysize);
if (error)
break;
if (!(log_entry->tlm_buf.tlb_eventflags & TLB_FLAG_HDR)) {
error = tcp_log_copyout(sopt, zerobuf,
((uint8_t *)out_entry) + entrysize,
sizeof(struct tcp_log_buffer) - entrysize);
}
/*
* Copy out the verbose bit, if needed. Either way,
* increment the output pointer the correct amount.
*/
if (log_entry->tlm_buf.tlb_eventflags & TLB_FLAG_VERBOSE) {
error = tcp_log_copyout(sopt, &log_entry->tlm_v,
out_entry->tlb_verbose,
sizeof(struct tcp_log_verbose));
if (error)
break;
out_entry = (struct tcp_log_buffer *)
(((uint8_t *) (out_entry + 1)) +
sizeof(struct tcp_log_verbose));
} else
out_entry++;
}
*end = out_entry;
KASSERT(error || count == 0,
("%s:%d: Less than expected count (%d) processing list %p"
" (%d remain)", __func__, __LINE__, orig_count,
log_tailqp, count));
return (error);
}
/*
* Copy out the buffer. Note that we do incremental copying, so
* sooptcopyout() won't work. However, the goal is to produce the same
* end result as if we copied in the entire user buffer, updated it,
* and then used sooptcopyout() to copy it out.
*
* NOTE: This should be called with a write lock on the PCB; however,
* the function will drop it after it extracts the data from the TCPCB.
*/
int
tcp_log_getlogbuf(struct sockopt *sopt, struct tcpcb *tp)
{
struct tcp_log_stailq log_tailq;
struct tcp_log_mem *log_entry, *log_next;
struct tcp_log_buffer *out_entry;
struct inpcb *inp;
size_t outsize, entrysize;
int error, outnum;
INP_WLOCK_ASSERT(tp->t_inpcb);
inp = tp->t_inpcb;
/*
* Determine which log entries will fit in the buffer. As an
* optimization, skip this if all the entries will clearly fit
* in the buffer. (However, get an exact size if we are using
* INVARIANTS.)
*/
#ifndef INVARIANTS
if (sopt->sopt_valsize / (sizeof(struct tcp_log_buffer) +
sizeof(struct tcp_log_verbose)) >= tp->t_lognum) {
log_entry = STAILQ_LAST(&tp->t_logs, tcp_log_mem, tlm_queue);
log_next = NULL;
outsize = 0;
outnum = tp->t_lognum;
} else {
#endif
outsize = outnum = 0;
log_entry = NULL;
STAILQ_FOREACH(log_next, &tp->t_logs, tlm_queue) {
entrysize = sizeof(struct tcp_log_buffer);
if (log_next->tlm_buf.tlb_eventflags &
TLB_FLAG_VERBOSE)
entrysize += sizeof(struct tcp_log_verbose);
if ((sopt->sopt_valsize - outsize) < entrysize)
break;
outsize += entrysize;
outnum++;
log_entry = log_next;
}
KASSERT(outsize <= sopt->sopt_valsize,
("%s: calculated output size (%zu) greater than available"
"space (%zu)", __func__, outsize, sopt->sopt_valsize));
#ifndef INVARIANTS
}
#endif
/*
* Copy traditional sooptcopyout() behavior: if sopt->sopt_val
* is NULL, silently skip the copy. However, in this case, we
* will leave the list alone and return. Functionally, this
* gives userspace a way to poll for an approximate buffer
* size they will need to get the log entries.
*/
if (sopt->sopt_val == NULL) {
INP_WUNLOCK(inp);
if (outsize == 0) {
outsize = outnum * (sizeof(struct tcp_log_buffer) +
sizeof(struct tcp_log_verbose));
}
if (sopt->sopt_valsize > outsize)
sopt->sopt_valsize = outsize;
return (0);
}
/*
* Break apart the list. We'll save the ones we want to copy
* out locally and remove them from the TCPCB list. We can
* then drop the INPCB lock while we do the copyout.
*
* There are roughly three cases:
* 1. There was nothing to copy out. That's easy: drop the
* lock and return.
* 2. We are copying out the entire list. Again, that's easy:
* move the whole list.
* 3. We are copying out a partial list. That's harder. We
* need to update the list book-keeping entries.
*/
if (log_entry != NULL && log_next == NULL) {
/* Move entire list. */
KASSERT(outnum == tp->t_lognum,
("%s:%d: outnum (%d) should match tp->t_lognum (%d)",
__func__, __LINE__, outnum, tp->t_lognum));
log_tailq = tp->t_logs;
tp->t_lognum = 0;
STAILQ_INIT(&tp->t_logs);
} else if (log_entry != NULL) {
/* Move partial list. */
KASSERT(outnum < tp->t_lognum,
("%s:%d: outnum (%d) not less than tp->t_lognum (%d)",
__func__, __LINE__, outnum, tp->t_lognum));
STAILQ_FIRST(&log_tailq) = STAILQ_FIRST(&tp->t_logs);
STAILQ_FIRST(&tp->t_logs) = STAILQ_NEXT(log_entry, tlm_queue);
KASSERT(STAILQ_NEXT(log_entry, tlm_queue) != NULL,
("%s:%d: tp->t_logs is unexpectedly shorter than expected"
"(tp: %p, log_tailq: %p, outnum: %d, tp->t_lognum: %d)",
__func__, __LINE__, tp, &log_tailq, outnum, tp->t_lognum));
STAILQ_NEXT(log_entry, tlm_queue) = NULL;
log_tailq.stqh_last = &STAILQ_NEXT(log_entry, tlm_queue);
tp->t_lognum -= outnum;
} else
STAILQ_INIT(&log_tailq);
/* Drop the PCB lock. */
INP_WUNLOCK(inp);
/* Copy the data out. */
error = tcp_log_logs_to_buf(sopt, &log_tailq, &out_entry, outnum);
if (error) {
/* Restore list */
INP_WLOCK(inp);
if ((inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) == 0) {
tp = intotcpcb(inp);
/* Merge the two lists. */
STAILQ_CONCAT(&log_tailq, &tp->t_logs);
tp->t_logs = log_tailq;
tp->t_lognum += outnum;
}
INP_WUNLOCK(inp);
} else {
/* Sanity check entries */
KASSERT(((caddr_t)out_entry - (caddr_t)sopt->sopt_val) ==
outsize, ("%s: Actual output size (%zu) != "
"calculated output size (%zu)", __func__,
(size_t)((caddr_t)out_entry - (caddr_t)sopt->sopt_val),
outsize));
/* Free the entries we just copied out. */
STAILQ_FOREACH_SAFE(log_entry, &log_tailq, tlm_queue, log_next) {
tcp_log_entry_refcnt_rem(log_entry);
uma_zfree(tcp_log_zone, log_entry);
}
}
sopt->sopt_valsize = (size_t)((caddr_t)out_entry -
(caddr_t)sopt->sopt_val);
return (error);
}
static void
tcp_log_free_queue(struct tcp_log_dev_queue *param)
{
struct tcp_log_dev_log_queue *entry;
KASSERT(param != NULL, ("%s: called with NULL param", __func__));
if (param == NULL)
return;
entry = (struct tcp_log_dev_log_queue *)param;
/* Free the entries. */
tcp_log_free_entries(&entry->tldl_entries, &entry->tldl_count);
/* Free the buffer, if it is allocated. */
if (entry->tldl_common.tldq_buf != NULL)
free(entry->tldl_common.tldq_buf, M_TCPLOGDEV);
/* Free the queue entry. */
free(entry, M_TCPLOGDEV);
}
static struct tcp_log_common_header *
tcp_log_expandlogbuf(struct tcp_log_dev_queue *param)
{
struct tcp_log_dev_log_queue *entry;
struct tcp_log_header *hdr;
uint8_t *end;
struct sockopt sopt;
int error;
entry = (struct tcp_log_dev_log_queue *)param;
/* Take a worst-case guess at space needs. */
sopt.sopt_valsize = sizeof(struct tcp_log_header) +
entry->tldl_count * (sizeof(struct tcp_log_buffer) +
sizeof(struct tcp_log_verbose));
hdr = malloc(sopt.sopt_valsize, M_TCPLOGDEV, M_NOWAIT);
if (hdr == NULL) {
#ifdef TCPLOG_DEBUG_COUNTERS
counter_u64_add(tcp_log_que_fail5, entry->tldl_count);
#endif
return (NULL);
}
sopt.sopt_val = hdr + 1;
sopt.sopt_valsize -= sizeof(struct tcp_log_header);
sopt.sopt_td = NULL;
error = tcp_log_logs_to_buf(&sopt, &entry->tldl_entries,
(struct tcp_log_buffer **)&end, entry->tldl_count);
if (error) {
free(hdr, M_TCPLOGDEV);
return (NULL);
}
/* Free the entries. */
tcp_log_free_entries(&entry->tldl_entries, &entry->tldl_count);
entry->tldl_count = 0;
memset(hdr, 0, sizeof(struct tcp_log_header));
hdr->tlh_version = TCP_LOG_BUF_VER;
hdr->tlh_type = TCP_LOG_DEV_TYPE_BBR;
hdr->tlh_length = end - (uint8_t *)hdr;
hdr->tlh_ie = entry->tldl_ie;
hdr->tlh_af = entry->tldl_af;
getboottime(&hdr->tlh_offset);
strlcpy(hdr->tlh_id, entry->tldl_id, TCP_LOG_ID_LEN);
strlcpy(hdr->tlh_tag, entry->tldl_tag, TCP_LOG_TAG_LEN);
strlcpy(hdr->tlh_reason, entry->tldl_reason, TCP_LOG_REASON_LEN);
return ((struct tcp_log_common_header *)hdr);
}
/*
* Queue the tcpcb's log buffer for transmission via the log buffer facility.
*
* NOTE: This should be called with a write lock on the PCB.
*
* how should be M_WAITOK or M_NOWAIT. If M_WAITOK, the function will drop
* and reacquire the INP lock if it needs to do so.
*
* If force is false, this will only dump auto-logged sessions if
* tcp_log_auto_all is true or if there is a log ID defined for the session.
*/
int
tcp_log_dump_tp_logbuf(struct tcpcb *tp, char *reason, int how, bool force)
{
struct tcp_log_dev_log_queue *entry;
struct inpcb *inp;
#ifdef TCPLOG_DEBUG_COUNTERS
int num_entries;
#endif
inp = tp->t_inpcb;
INP_WLOCK_ASSERT(inp);
/* If there are no log entries, there is nothing to do. */
if (tp->t_lognum == 0)
return (0);
/* Check for a log ID. */
if (tp->t_lib == NULL && (tp->t_flags2 & TF2_LOG_AUTO) &&
!tcp_log_auto_all && !force) {
struct tcp_log_mem *log_entry;
/*
* We needed a log ID and none was found. Free the log entries
* and return success. Also, cancel further logging. If the
* session doesn't have a log ID by now, we'll assume it isn't
* going to get one.
*/
while ((log_entry = STAILQ_FIRST(&tp->t_logs)) != NULL)
tcp_log_remove_log_head(tp, log_entry);
KASSERT(tp->t_lognum == 0,
("%s: After freeing entries, tp->t_lognum=%d (expected 0)",
__func__, tp->t_lognum));
tp->t_logstate = TCP_LOG_STATE_OFF;
return (0);
}
/*
* Allocate memory. If we must wait, we'll need to drop the locks
* and reacquire them (and do all the related business that goes
* along with that).
*/
entry = malloc(sizeof(struct tcp_log_dev_log_queue), M_TCPLOGDEV,
M_NOWAIT);
if (entry == NULL && (how & M_NOWAIT)) {
#ifdef TCPLOG_DEBUG_COUNTERS
counter_u64_add(tcp_log_que_fail3, 1);
#endif
return (ENOBUFS);
}
if (entry == NULL) {
INP_WUNLOCK(inp);
entry = malloc(sizeof(struct tcp_log_dev_log_queue),
M_TCPLOGDEV, M_WAITOK);
INP_WLOCK(inp);
/*
* Note that this check is slightly overly-restrictive in
* that the TCB can survive either of these events.
* However, there is currently not a good way to ensure
* that is the case. So, if we hit this M_WAIT path, we
* may end up dropping some entries. That seems like a
* small price to pay for safety.
*/
if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
free(entry, M_TCPLOGDEV);
#ifdef TCPLOG_DEBUG_COUNTERS
counter_u64_add(tcp_log_que_fail2, 1);
#endif
return (ECONNRESET);
}
tp = intotcpcb(inp);
if (tp->t_lognum == 0) {
free(entry, M_TCPLOGDEV);
return (0);
}
}
/* Fill in the unique parts of the queue entry. */
if (tp->t_lib != NULL) {
strlcpy(entry->tldl_id, tp->t_lib->tlb_id, TCP_LOG_ID_LEN);
strlcpy(entry->tldl_tag, tp->t_lib->tlb_tag, TCP_LOG_TAG_LEN);
} else {
strlcpy(entry->tldl_id, "UNKNOWN", TCP_LOG_ID_LEN);
strlcpy(entry->tldl_tag, "UNKNOWN", TCP_LOG_TAG_LEN);
}
if (reason != NULL)
strlcpy(entry->tldl_reason, reason, TCP_LOG_REASON_LEN);
else
strlcpy(entry->tldl_reason, "UNKNOWN", TCP_LOG_ID_LEN);
entry->tldl_ie = inp->inp_inc.inc_ie;
if (inp->inp_inc.inc_flags & INC_ISIPV6)
entry->tldl_af = AF_INET6;
else
entry->tldl_af = AF_INET;
entry->tldl_entries = tp->t_logs;
entry->tldl_count = tp->t_lognum;
/* Fill in the common parts of the queue entry. */
entry->tldl_common.tldq_buf = NULL;
entry->tldl_common.tldq_xform = tcp_log_expandlogbuf;
entry->tldl_common.tldq_dtor = tcp_log_free_queue;
/* Clear the log data from the TCPCB. */
#ifdef TCPLOG_DEBUG_COUNTERS
num_entries = tp->t_lognum;
#endif
tp->t_lognum = 0;
STAILQ_INIT(&tp->t_logs);
/* Add the entry. If no one is listening, free the entry. */
if (tcp_log_dev_add_log((struct tcp_log_dev_queue *)entry)) {
tcp_log_free_queue((struct tcp_log_dev_queue *)entry);
#ifdef TCPLOG_DEBUG_COUNTERS
counter_u64_add(tcp_log_que_fail1, num_entries);
} else {
counter_u64_add(tcp_log_queued, num_entries);
#endif
}
return (0);
}
/*
* Queue the log_id_node's log buffers for transmission via the log buffer
* facility.
*
* NOTE: This should be called with the bucket locked and referenced.
*
* how should be M_WAITOK or M_NOWAIT. If M_WAITOK, the function will drop
* and reacquire the bucket lock if it needs to do so. (The caller must
* ensure that the tln is no longer on any lists so no one else will mess
* with this while the lock is dropped!)
*/
static int
tcp_log_dump_node_logbuf(struct tcp_log_id_node *tln, char *reason, int how)
{
struct tcp_log_dev_log_queue *entry;
struct tcp_log_id_bucket *tlb;
tlb = tln->tln_bucket;
TCPID_BUCKET_LOCK_ASSERT(tlb);
KASSERT(tlb->tlb_refcnt > 0,
("%s:%d: Called with unreferenced bucket (tln=%p, tlb=%p)",
__func__, __LINE__, tln, tlb));
KASSERT(tln->tln_closed,
("%s:%d: Called for node with tln_closed==false (tln=%p)",
__func__, __LINE__, tln));
/* If there are no log entries, there is nothing to do. */
if (tln->tln_count == 0)
return (0);
/*
* Allocate memory. If we must wait, we'll need to drop the locks
* and reacquire them (and do all the related business that goes
* along with that).
*/
entry = malloc(sizeof(struct tcp_log_dev_log_queue), M_TCPLOGDEV,
M_NOWAIT);
if (entry == NULL && (how & M_NOWAIT))
return (ENOBUFS);
if (entry == NULL) {
TCPID_BUCKET_UNLOCK(tlb);
entry = malloc(sizeof(struct tcp_log_dev_log_queue),
M_TCPLOGDEV, M_WAITOK);
TCPID_BUCKET_LOCK(tlb);
}
/* Fill in the common parts of the queue entry.. */
entry->tldl_common.tldq_buf = NULL;
entry->tldl_common.tldq_xform = tcp_log_expandlogbuf;
entry->tldl_common.tldq_dtor = tcp_log_free_queue;
/* Fill in the unique parts of the queue entry. */
strlcpy(entry->tldl_id, tlb->tlb_id, TCP_LOG_ID_LEN);
strlcpy(entry->tldl_tag, tlb->tlb_tag, TCP_LOG_TAG_LEN);
if (reason != NULL)
strlcpy(entry->tldl_reason, reason, TCP_LOG_REASON_LEN);
else
strlcpy(entry->tldl_reason, "UNKNOWN", TCP_LOG_ID_LEN);
entry->tldl_ie = tln->tln_ie;
entry->tldl_entries = tln->tln_entries;
entry->tldl_count = tln->tln_count;
entry->tldl_af = tln->tln_af;
/* Add the entry. If no one is listening, free the entry. */
if (tcp_log_dev_add_log((struct tcp_log_dev_queue *)entry))
tcp_log_free_queue((struct tcp_log_dev_queue *)entry);
return (0);
}
/*
* Queue the log buffers for all sessions in a bucket for transmissions via
* the log buffer facility.
*
* NOTE: This should be called with a locked bucket; however, the function
* will drop the lock.
*/
#define LOCAL_SAVE 10
static void
tcp_log_dumpbucketlogs(struct tcp_log_id_bucket *tlb, char *reason)
{
struct tcp_log_id_node local_entries[LOCAL_SAVE];
struct inpcb *inp;
struct tcpcb *tp;
struct tcp_log_id_node *cur_tln, *prev_tln, *tmp_tln;
int i, num_local_entries, tree_locked;
bool expireq_locked;
TCPID_BUCKET_LOCK_ASSERT(tlb);
/*
* Take a reference on the bucket to keep it from disappearing until
* we are done.
*/
TCPID_BUCKET_REF(tlb);
/*
* We'll try to create these without dropping locks. However, we
* might very well need to drop locks to get memory. If that's the
* case, we'll save up to 10 on the stack, and sacrifice the rest.
* (Otherwise, we need to worry about finding our place again in a
* potentially changed list. It just doesn't seem worth the trouble
* to do that.
*/
expireq_locked = false;
num_local_entries = 0;
prev_tln = NULL;
tree_locked = TREE_UNLOCKED;
SLIST_FOREACH_SAFE(cur_tln, &tlb->tlb_head, tln_list, tmp_tln) {
/*
* If this isn't associated with a TCPCB, we can pull it off
* the list now. We need to be careful that the expire timer
* hasn't already taken ownership (tln_expiretime == SBT_MAX).
* If so, we let the expire timer code free the data.
*/
if (cur_tln->tln_closed) {
no_inp:
/*
* Get the expireq lock so we can get a consistent
* read of tln_expiretime and so we can remove this
* from the expireq.
*/
if (!expireq_locked) {
TCPLOG_EXPIREQ_LOCK();
expireq_locked = true;
}
/*
* We ignore entries with tln_expiretime == SBT_MAX.
* The expire timer code already owns those.
*/
KASSERT(cur_tln->tln_expiretime > (sbintime_t) 0,
("%s:%d: node on the expire queue without positive "
"expire time", __func__, __LINE__));
if (cur_tln->tln_expiretime == SBT_MAX) {
prev_tln = cur_tln;
continue;
}
/* Remove the entry from the expireq. */
STAILQ_REMOVE(&tcp_log_expireq_head, cur_tln,
tcp_log_id_node, tln_expireq);
/* Remove the entry from the bucket. */
if (prev_tln != NULL)
SLIST_REMOVE_AFTER(prev_tln, tln_list);
else
SLIST_REMOVE_HEAD(&tlb->tlb_head, tln_list);
/*
* Drop the INP and bucket reference counts. Due to
* lock-ordering rules, we need to drop the expire
* queue lock.
*/
TCPLOG_EXPIREQ_UNLOCK();
expireq_locked = false;
/* Drop the INP reference. */
INP_WLOCK(cur_tln->tln_inp);
if (!in_pcbrele_wlocked(cur_tln->tln_inp))
INP_WUNLOCK(cur_tln->tln_inp);
if (tcp_log_unref_bucket(tlb, &tree_locked, NULL)) {
#ifdef INVARIANTS
panic("%s: Bucket refcount unexpectedly 0.",
__func__);
#endif
/*
* Recover as best we can: free the entry we
* own.
*/
tcp_log_free_entries(&cur_tln->tln_entries,
&cur_tln->tln_count);
uma_zfree(tcp_log_node_zone, cur_tln);
goto done;
}
if (tcp_log_dump_node_logbuf(cur_tln, reason,
M_NOWAIT)) {
/*
* If we have sapce, save the entries locally.
* Otherwise, free them.
*/
if (num_local_entries < LOCAL_SAVE) {
local_entries[num_local_entries] =
*cur_tln;
num_local_entries++;
} else {
tcp_log_free_entries(
&cur_tln->tln_entries,
&cur_tln->tln_count);
}
}
/* No matter what, we are done with the node now. */
uma_zfree(tcp_log_node_zone, cur_tln);
/*
* Because we removed this entry from the list, prev_tln
* (which tracks the previous entry still on the tlb
* list) remains unchanged.
*/
continue;
}
/*
* If we get to this point, the session data is still held in
* the TCPCB. So, we need to pull the data out of that.
*
* We will need to drop the expireq lock so we can lock the INP.
* We can then try to extract the data the "easy" way. If that
* fails, we'll save the log entries for later.
*/
if (expireq_locked) {
TCPLOG_EXPIREQ_UNLOCK();
expireq_locked = false;
}
/* Lock the INP and then re-check the state. */
inp = cur_tln->tln_inp;
INP_WLOCK(inp);
/*
* If we caught this while it was transitioning, the data
* might have moved from the TCPCB to the tln (signified by
* setting tln_closed to true. If so, treat this like an
* inactive connection.
*/
if (cur_tln->tln_closed) {
/*
* It looks like we may have caught this connection
* while it was transitioning from active to inactive.
* Treat this like an inactive connection.
*/
INP_WUNLOCK(inp);
goto no_inp;
}
/*
* Try to dump the data from the tp without dropping the lock.
* If this fails, try to save off the data locally.
*/
tp = cur_tln->tln_tp;
if (tcp_log_dump_tp_logbuf(tp, reason, M_NOWAIT, true) &&
num_local_entries < LOCAL_SAVE) {
tcp_log_move_tp_to_node(tp,
&local_entries[num_local_entries]);
local_entries[num_local_entries].tln_closed = 1;
KASSERT(local_entries[num_local_entries].tln_bucket ==
tlb, ("%s: %d: bucket mismatch for node %p",
__func__, __LINE__, cur_tln));
num_local_entries++;
}
INP_WUNLOCK(inp);
/*
* We are goint to leave the current tln on the list. It will
* become the previous tln.
*/
prev_tln = cur_tln;
}
/* Drop our locks, if any. */
KASSERT(tree_locked == TREE_UNLOCKED,
("%s: %d: tree unexpectedly locked", __func__, __LINE__));
switch (tree_locked) {
case TREE_WLOCKED:
TCPID_TREE_WUNLOCK();
tree_locked = TREE_UNLOCKED;
break;
case TREE_RLOCKED:
TCPID_TREE_RUNLOCK();
tree_locked = TREE_UNLOCKED;
break;
}
if (expireq_locked) {
TCPLOG_EXPIREQ_UNLOCK();
expireq_locked = false;
}
/*
* Try again for any saved entries. tcp_log_dump_node_logbuf() is
* guaranteed to free the log entries within the node. And, since
* the node itself is on our stack, we don't need to free it.
*/
for (i = 0; i < num_local_entries; i++)
tcp_log_dump_node_logbuf(&local_entries[i], reason, M_WAITOK);
/* Drop our reference. */
if (!tcp_log_unref_bucket(tlb, &tree_locked, NULL))
TCPID_BUCKET_UNLOCK(tlb);
done:
/* Drop our locks, if any. */
switch (tree_locked) {
case TREE_WLOCKED:
TCPID_TREE_WUNLOCK();
break;
case TREE_RLOCKED:
TCPID_TREE_RUNLOCK();
break;
}
if (expireq_locked)
TCPLOG_EXPIREQ_UNLOCK();
}
#undef LOCAL_SAVE
/*
* Queue the log buffers for all sessions in a bucket for transmissions via
* the log buffer facility.
*
* NOTE: This should be called with a locked INP; however, the function
* will drop the lock.
*/
void
tcp_log_dump_tp_bucket_logbufs(struct tcpcb *tp, char *reason)
{
struct tcp_log_id_bucket *tlb;
int tree_locked;
/* Figure out our bucket and lock it. */
INP_WLOCK_ASSERT(tp->t_inpcb);
tlb = tp->t_lib;
if (tlb == NULL) {
/*
* No bucket; treat this like a request to dump a single
* session's traces.
*/
(void)tcp_log_dump_tp_logbuf(tp, reason, M_WAITOK, true);
INP_WUNLOCK(tp->t_inpcb);
return;
}
TCPID_BUCKET_REF(tlb);
INP_WUNLOCK(tp->t_inpcb);
TCPID_BUCKET_LOCK(tlb);
/* If we are the last reference, we have nothing more to do here. */
tree_locked = TREE_UNLOCKED;
if (tcp_log_unref_bucket(tlb, &tree_locked, NULL)) {
switch (tree_locked) {
case TREE_WLOCKED:
TCPID_TREE_WUNLOCK();
break;
case TREE_RLOCKED:
TCPID_TREE_RUNLOCK();
break;
}
return;
}
/* Turn this over to tcp_log_dumpbucketlogs() to finish the work. */
tcp_log_dumpbucketlogs(tlb, reason);
}
/*
* Mark the end of a flow with the current stack. A stack can add
* stack-specific info to this trace event by overriding this
* function (see bbr_log_flowend() for example).
*/
void
tcp_log_flowend(struct tcpcb *tp)
{
if (tp->t_logstate != TCP_LOG_STATE_OFF) {
struct socket *so = tp->t_inpcb->inp_socket;
TCP_LOG_EVENT(tp, NULL, &so->so_rcv, &so->so_snd,
TCP_LOG_FLOWEND, 0, 0, NULL, false);
}
}
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