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freebsd-dev/sys/netinet/tcp_log_buf.c
Randall Stewart 8021928623 Fix a small bug in the tcp_log_id where the bucket 
was unlocked and yet the bucket-unlock flag was not
changed to false. This can cause a panic if INVARIANTS
is on and we go through the right path (though rare).
This fixes the correct bug :)

Reported by:	syzbot+179a1ad49f3c4c215fa2@syzkaller.appspotmail.com
Reviewed by:	tuexen@
2019-04-10 18:58:11 +00:00

2436 lines
71 KiB
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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/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.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/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;
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, 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_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
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];
RB_ENTRY(tcp_log_id_bucket) tlb_rb;
struct tcp_log_id_head tlb_head;
struct mtx tlb_mtx;
volatile u_int tlb_refcnt;
};
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 &&
(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);
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 NETFLIX
if (V_tcp_perconn_stats_enable == 2 && tp->t_stats == NULL)
(void)tcp_stats_sample_rollthedice(tp, tlb_id, strlen(tlb_id));
#endif
}
/*
* 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)) {
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;
}
/*
* 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);
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); \
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);
}
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;
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 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
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.
*/
if (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);
/*
* 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;
}
/*
* 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);
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 < tcp_log_session_limit) {
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(sack_newdata);
COPY_STAT(rcv_wnd);
COPY_STAT_T(dupacks);
COPY_STAT_T(segqlen);
COPY_STAT(snd_numholes);
COPY_STAT(snd_scale);
COPY_STAT(rcv_scale);
#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);
}
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_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);
else
strlcpy(entry->tldl_id, "UNKNOWN", TCP_LOG_ID_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);
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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