freebsd-dev/sys/net/if_var.h

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/*-
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*
* From: @(#)if.h 8.1 (Berkeley) 6/10/93
1999-08-28 01:08:13 +00:00
* $FreeBSD$
*/
#ifndef _NET_IF_VAR_H_
#define _NET_IF_VAR_H_
/*
* Structures defining a network interface, providing a packet
* transport mechanism (ala level 0 of the PUP protocols).
*
* Each interface accepts output datagrams of a specified maximum
* length, and provides higher level routines with input datagrams
* received from its medium.
*
* Output occurs when the routine if_output is called, with three parameters:
* (*ifp->if_output)(ifp, m, dst, rt)
* Here m is the mbuf chain to be sent and dst is the destination address.
* The output routine encapsulates the supplied datagram if necessary,
* and then transmits it on its medium.
*
* On input, each interface unwraps the data received by it, and either
* places it on the input queue of an internetwork datagram routine
* and posts the associated software interrupt, or passes the datagram to a raw
* packet input routine.
*
* Routines exist for locating interfaces by their addresses
* or for locating an interface on a certain network, as well as more general
* routing and gateway routines maintaining information used to locate
* interfaces. These routines live in the files if.c and route.c
*/
struct rtentry; /* ifa_rtrequest */
struct rt_addrinfo; /* ifa_rtrequest */
struct socket;
struct carp_if;
struct carp_softc;
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struct ifvlantrunk;
struct route; /* if_output */
struct vnet;
#ifdef _KERNEL
#include <sys/mbuf.h> /* ifqueue only? */
#include <sys/buf_ring.h>
Build on Jeff Roberson's linker-set based dynamic per-CPU allocator (DPCPU), as suggested by Peter Wemm, and implement a new per-virtual network stack memory allocator. Modify vnet to use the allocator instead of monolithic global container structures (vinet, ...). This change solves many binary compatibility problems associated with VIMAGE, and restores ELF symbols for virtualized global variables. Each virtualized global variable exists as a "reference copy", and also once per virtual network stack. Virtualized global variables are tagged at compile-time, placing the in a special linker set, which is loaded into a contiguous region of kernel memory. Virtualized global variables in the base kernel are linked as normal, but those in modules are copied and relocated to a reserved portion of the kernel's vnet region with the help of a the kernel linker. Virtualized global variables exist in per-vnet memory set up when the network stack instance is created, and are initialized statically from the reference copy. Run-time access occurs via an accessor macro, which converts from the current vnet and requested symbol to a per-vnet address. When "options VIMAGE" is not compiled into the kernel, normal global ELF symbols will be used instead and indirection is avoided. This change restores static initialization for network stack global variables, restores support for non-global symbols and types, eliminates the need for many subsystem constructors, eliminates large per-subsystem structures that caused many binary compatibility issues both for monitoring applications (netstat) and kernel modules, removes the per-function INIT_VNET_*() macros throughout the stack, eliminates the need for vnet_symmap ksym(2) munging, and eliminates duplicate definitions of virtualized globals under VIMAGE_GLOBALS. Bump __FreeBSD_version and update UPDATING. Portions submitted by: bz Reviewed by: bz, zec Discussed with: gnn, jamie, jeff, jhb, julian, sam Suggested by: peter Approved by: re (kensmith)
2009-07-14 22:48:30 +00:00
#include <net/vnet.h>
#endif /* _KERNEL */
#include <sys/counter.h>
#include <sys/lock.h> /* XXX */
#include <sys/mutex.h> /* struct ifqueue */
#include <sys/rwlock.h> /* XXX */
#include <sys/sx.h> /* XXX */
#include <sys/_task.h> /* if_link_task */
#define IF_DUNIT_NONE -1
#include <altq/if_altq.h>
TAILQ_HEAD(ifnethead, ifnet); /* we use TAILQs so that the order of */
TAILQ_HEAD(ifaddrhead, ifaddr); /* instantiation is preserved in the list */
TAILQ_HEAD(ifmultihead, ifmultiaddr);
TAILQ_HEAD(ifgrouphead, ifg_group);
#ifdef _KERNEL
VNET_DECLARE(struct pfil_head, link_pfil_hook); /* packet filter hooks */
#define V_link_pfil_hook VNET(link_pfil_hook)
#endif /* _KERNEL */
/*
* Structure defining a network interface.
*
* Size ILP32: 592 (approx)
* LP64: 1048 (approx)
*/
struct ifnet {
/* General book keeping of interface lists. */
TAILQ_ENTRY(ifnet) if_link; /* all struct ifnets are chained */
LIST_ENTRY(ifnet) if_clones; /* interfaces of a cloner */
TAILQ_HEAD(, ifg_list) if_groups; /* linked list of groups per if */
/* protected by if_addr_lock */
u_char if_alloctype; /* if_type at time of allocation */
/* Driver and protocol specific information that remains stable. */
void *if_softc; /* pointer to driver state */
void *if_llsoftc; /* link layer softc */
void *if_l2com; /* pointer to protocol bits */
const char *if_dname; /* driver name */
int if_dunit; /* unit or IF_DUNIT_NONE */
u_short if_index; /* numeric abbreviation for this if */
short if_index_reserved; /* spare space to grow if_index */
char if_xname[IFNAMSIZ]; /* external name (name + unit) */
char *if_description; /* interface description */
/* Variable fields that are touched by the stack and drivers. */
int if_flags; /* up/down, broadcast, etc. */
int if_capabilities; /* interface features & capabilities */
int if_capenable; /* enabled features & capabilities */
void *if_linkmib; /* link-type-specific MIB data */
size_t if_linkmiblen; /* length of above data */
int if_drv_flags; /* driver-managed status flags */
Start to address a number of races relating to use of ifnet pointers after the corresponding interface has been destroyed: (1) Add an ifnet refcount, ifp->if_refcount. Initialize it to 1 in if_alloc(), and modify if_free_type() to decrement and check the refcount. (2) Add new if_ref() and if_rele() interfaces to allow kernel code walking global interface lists to release IFNET_[RW]LOCK() yet keep the ifnet stable. Currently, if_rele() is a no-op wrapper around if_free(), but this may change in the future. (3) Add new ifnet field, if_alloctype, which caches the type passed to if_alloc(), but unlike if_type, won't be changed by drivers. This allows asynchronous free's of the interface after the driver has released it to still use the right type. Use that instead of the type passed to if_free_type(), but assert that they are the same (might have to rethink this if that doesn't work out). (4) Add a new ifnet_byindex_ref(), which looks up an interface by index and returns a reference rather than a pointer to it. (5) Fix if_alloc() to fully initialize the if_addr_mtx before hooking up the ifnet to global lists. (6) Modify sysctls in if_mib.c to use ifnet_byindex_ref() and release the ifnet when done. When this change is MFC'd, it will need to replace if_ispare fields rather than adding new fields in order to avoid breaking the binary interface. Once this change is MFC'd, if_free_type() should be removed, as its 'type' argument is now optional. This refcount is not appropriate for counting mbuf pkthdr references, and also not for counting entry into the device driver via ifnet function pointers. An rmlock may be appropriate for the latter. Rather, this is about ensuring data structure stability when reaching an ifnet via global ifnet lists and tables followed by copy in or out of userspace. MFC after: 3 weeks Reported by: mdtancsa Reviewed by: brooks
2009-04-21 22:43:32 +00:00
u_int if_refcount; /* reference count */
struct ifaltq if_snd; /* output queue (includes altq) */
struct if_data if_data; /* type information and statistics */
struct task if_linktask; /* task for link change events */
/* Addresses of different protocol families assigned to this if. */
struct rwlock if_addr_lock; /* lock to protect address lists */
/*
* if_addrhead is the list of all addresses associated to
* an interface.
* Some code in the kernel assumes that first element
* of the list has type AF_LINK, and contains sockaddr_dl
* addresses which store the link-level address and the name
* of the interface.
* However, access to the AF_LINK address through this
* field is deprecated. Use if_addr or ifaddr_byindex() instead.
*/
struct ifaddrhead if_addrhead; /* linked list of addresses per if */
struct ifmultihead if_multiaddrs; /* multicast addresses configured */
int if_amcount; /* number of all-multicast requests */
struct ifaddr *if_addr; /* pointer to link-level address */
const u_int8_t *if_broadcastaddr; /* linklevel broadcast bytestring */
struct rwlock if_afdata_lock;
void *if_afdata[AF_MAX];
int if_afdata_initialized;
/* Additional features hung off the interface. */
u_int if_fib; /* interface FIB */
struct vnet *if_vnet; /* pointer to network stack instance */
struct vnet *if_home_vnet; /* where this ifnet originates from */
struct ifvlantrunk *if_vlantrunk; /* pointer to 802.1q data */
struct bpf_if *if_bpf; /* packet filter structure */
int if_pcount; /* number of promiscuous listeners */
void *if_bridge; /* bridge glue */
void *if_lagg; /* lagg glue */
void *if_pf_kif; /* pf glue */
struct carp_if *if_carp; /* carp interface structure */
struct label *if_label; /* interface MAC label */
/* Various procedures of the layer2 encapsulation and drivers. */
int (*if_output) /* output routine (enqueue) */
(struct ifnet *, struct mbuf *, const struct sockaddr *,
struct route *);
void (*if_input) /* input routine (from h/w driver) */
(struct ifnet *, struct mbuf *);
void (*if_start) /* initiate output routine */
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(struct ifnet *);
int (*if_ioctl) /* ioctl routine */
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(struct ifnet *, u_long, caddr_t);
void (*if_init) /* Init routine */
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(void *);
int (*if_resolvemulti) /* validate/resolve multicast */
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(struct ifnet *, struct sockaddr **, struct sockaddr *);
void (*if_qflush) /* flush any queues */
(struct ifnet *);
int (*if_transmit) /* initiate output routine */
(struct ifnet *, struct mbuf *);
void (*if_reassign) /* reassign to vnet routine */
(struct ifnet *, struct vnet *, char *);
/* Stuff that's only temporary and doesn't belong here. */
u_int if_hw_tsomax; /* tso burst length limit, the minimum
* is (IP_MAXPACKET / 8).
* XXXAO: Have to find a better place
* for it eventually. */
/*
* Spare fields are added so that we can modify sensitive data
* structures without changing the kernel binary interface, and must
* be used with care where binary compatibility is required.
*/
char if_cspare[3];
int if_ispare[4];
void *if_unused[2];
void *if_pspare[8]; /* 1 netmap, 7 TDB */
};
#include <net/ifq.h> /* XXXAO: temporary unconditional include */
/*
* XXX These aliases are terribly dangerous because they could apply
* to anything.
*/
#define if_mtu if_data.ifi_mtu
#define if_type if_data.ifi_type
#define if_physical if_data.ifi_physical
#define if_addrlen if_data.ifi_addrlen
#define if_hdrlen if_data.ifi_hdrlen
#define if_metric if_data.ifi_metric
#define if_link_state if_data.ifi_link_state
#define if_baudrate if_data.ifi_baudrate
#define if_baudrate_pf if_data.ifi_baudrate_pf
#define if_hwassist if_data.ifi_hwassist
#define if_ipackets if_data.ifi_ipackets
#define if_ierrors if_data.ifi_ierrors
#define if_opackets if_data.ifi_opackets
#define if_oerrors if_data.ifi_oerrors
#define if_collisions if_data.ifi_collisions
#define if_ibytes if_data.ifi_ibytes
#define if_obytes if_data.ifi_obytes
#define if_imcasts if_data.ifi_imcasts
#define if_omcasts if_data.ifi_omcasts
#define if_iqdrops if_data.ifi_iqdrops
#define if_noproto if_data.ifi_noproto
#define if_lastchange if_data.ifi_lastchange
/* for compatibility with other BSDs */
#define if_addrlist if_addrhead
#define if_list if_link
#define if_name(ifp) ((ifp)->if_xname)
/*
* Locks for address lists on the network interface.
*/
#define IF_ADDR_LOCK_INIT(if) rw_init(&(if)->if_addr_lock, "if_addr_lock")
#define IF_ADDR_LOCK_DESTROY(if) rw_destroy(&(if)->if_addr_lock)
#define IF_ADDR_WLOCK(if) rw_wlock(&(if)->if_addr_lock)
#define IF_ADDR_WUNLOCK(if) rw_wunlock(&(if)->if_addr_lock)
#define IF_ADDR_RLOCK(if) rw_rlock(&(if)->if_addr_lock)
#define IF_ADDR_RUNLOCK(if) rw_runlock(&(if)->if_addr_lock)
#define IF_ADDR_LOCK_ASSERT(if) rw_assert(&(if)->if_addr_lock, RA_LOCKED)
#define IF_ADDR_WLOCK_ASSERT(if) rw_assert(&(if)->if_addr_lock, RA_WLOCKED)
/*
* Function variations on locking macros intended to be used by loadable
* kernel modules in order to divorce them from the internals of address list
* locking.
*/
void if_addr_rlock(struct ifnet *ifp); /* if_addrhead */
void if_addr_runlock(struct ifnet *ifp); /* if_addrhead */
void if_maddr_rlock(struct ifnet *ifp); /* if_multiaddrs */
void if_maddr_runlock(struct ifnet *ifp); /* if_multiaddrs */
#ifdef _KERNEL
#ifdef _SYS_EVENTHANDLER_H_
/* interface link layer address change event */
typedef void (*iflladdr_event_handler_t)(void *, struct ifnet *);
EVENTHANDLER_DECLARE(iflladdr_event, iflladdr_event_handler_t);
/* interface address change event */
typedef void (*ifaddr_event_handler_t)(void *, struct ifnet *);
EVENTHANDLER_DECLARE(ifaddr_event, ifaddr_event_handler_t);
/* new interface arrival event */
typedef void (*ifnet_arrival_event_handler_t)(void *, struct ifnet *);
EVENTHANDLER_DECLARE(ifnet_arrival_event, ifnet_arrival_event_handler_t);
/* interface departure event */
typedef void (*ifnet_departure_event_handler_t)(void *, struct ifnet *);
EVENTHANDLER_DECLARE(ifnet_departure_event, ifnet_departure_event_handler_t);
/* Interface link state change event */
typedef void (*ifnet_link_event_handler_t)(void *, struct ifnet *, int);
EVENTHANDLER_DECLARE(ifnet_link_event, ifnet_link_event_handler_t);
#endif /* _SYS_EVENTHANDLER_H_ */
/*
* interface groups
*/
struct ifg_group {
char ifg_group[IFNAMSIZ];
u_int ifg_refcnt;
void *ifg_pf_kif;
TAILQ_HEAD(, ifg_member) ifg_members;
TAILQ_ENTRY(ifg_group) ifg_next;
};
struct ifg_member {
TAILQ_ENTRY(ifg_member) ifgm_next;
struct ifnet *ifgm_ifp;
};
struct ifg_list {
struct ifg_group *ifgl_group;
TAILQ_ENTRY(ifg_list) ifgl_next;
};
#ifdef _SYS_EVENTHANDLER_H_
/* group attach event */
typedef void (*group_attach_event_handler_t)(void *, struct ifg_group *);
EVENTHANDLER_DECLARE(group_attach_event, group_attach_event_handler_t);
/* group detach event */
typedef void (*group_detach_event_handler_t)(void *, struct ifg_group *);
EVENTHANDLER_DECLARE(group_detach_event, group_detach_event_handler_t);
/* group change event */
typedef void (*group_change_event_handler_t)(void *, const char *);
EVENTHANDLER_DECLARE(group_change_event, group_change_event_handler_t);
#endif /* _SYS_EVENTHANDLER_H_ */
#define IF_AFDATA_LOCK_INIT(ifp) \
rw_init(&(ifp)->if_afdata_lock, "if_afdata")
#define IF_AFDATA_WLOCK(ifp) rw_wlock(&(ifp)->if_afdata_lock)
#define IF_AFDATA_RLOCK(ifp) rw_rlock(&(ifp)->if_afdata_lock)
#define IF_AFDATA_WUNLOCK(ifp) rw_wunlock(&(ifp)->if_afdata_lock)
#define IF_AFDATA_RUNLOCK(ifp) rw_runlock(&(ifp)->if_afdata_lock)
#define IF_AFDATA_LOCK(ifp) IF_AFDATA_WLOCK(ifp)
#define IF_AFDATA_UNLOCK(ifp) IF_AFDATA_WUNLOCK(ifp)
#define IF_AFDATA_TRYLOCK(ifp) rw_try_wlock(&(ifp)->if_afdata_lock)
#define IF_AFDATA_DESTROY(ifp) rw_destroy(&(ifp)->if_afdata_lock)
#define IF_AFDATA_LOCK_ASSERT(ifp) rw_assert(&(ifp)->if_afdata_lock, RA_LOCKED)
#define IF_AFDATA_RLOCK_ASSERT(ifp) rw_assert(&(ifp)->if_afdata_lock, RA_RLOCKED)
#define IF_AFDATA_WLOCK_ASSERT(ifp) rw_assert(&(ifp)->if_afdata_lock, RA_WLOCKED)
#define IF_AFDATA_UNLOCK_ASSERT(ifp) rw_assert(&(ifp)->if_afdata_lock, RA_UNLOCKED)
static __inline void
if_initbaudrate(struct ifnet *ifp, uintmax_t baud)
{
ifp->if_baudrate_pf = 0;
while (baud > (u_long)(~0UL)) {
baud /= 10;
ifp->if_baudrate_pf++;
}
ifp->if_baudrate = baud;
}
/*
* 72 was chosen below because it is the size of a TCP/IP
* header (40) + the minimum mss (32).
*/
#define IF_MINMTU 72
#define IF_MAXMTU 65535
#define TOEDEV(ifp) ((ifp)->if_llsoftc)
#endif /* _KERNEL */
/*
* The ifaddr structure contains information about one address
* of an interface. They are maintained by the different address families,
* are allocated and attached when an address is set, and are linked
* together so all addresses for an interface can be located.
*
* NOTE: a 'struct ifaddr' is always at the beginning of a larger
* chunk of malloc'ed memory, where we store the three addresses
* (ifa_addr, ifa_dstaddr and ifa_netmask) referenced here.
*/
#if defined(_KERNEL) || defined(_WANT_IFADDR)
struct ifaddr {
struct sockaddr *ifa_addr; /* address of interface */
struct sockaddr *ifa_dstaddr; /* other end of p-to-p link */
#define ifa_broadaddr ifa_dstaddr /* broadcast address interface */
struct sockaddr *ifa_netmask; /* used to determine subnet */
struct ifnet *ifa_ifp; /* back-pointer to interface */
struct carp_softc *ifa_carp; /* pointer to CARP data */
TAILQ_ENTRY(ifaddr) ifa_link; /* queue macro glue */
void (*ifa_rtrequest) /* check or clean routes (+ or -)'d */
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(int, struct rtentry *, struct rt_addrinfo *);
u_short ifa_flags; /* mostly rt_flags for cloning */
u_int ifa_refcnt; /* references to this structure */
int ifa_metric; /* cost of going out this interface */
int (*ifa_claim_addr) /* check if an addr goes to this if */
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(struct ifaddr *, struct sockaddr *);
counter_u64_t ifa_ipackets;
counter_u64_t ifa_opackets;
counter_u64_t ifa_ibytes;
counter_u64_t ifa_obytes;
};
#endif
#ifdef _KERNEL
#define IFA_ROUTE RTF_UP /* route installed */
#define IFA_RTSELF RTF_HOST /* loopback route to self installed */
/* For compatibility with other BSDs. SCTP uses it. */
#define ifa_list ifa_link
struct ifaddr * ifa_alloc(size_t size, int flags);
void ifa_free(struct ifaddr *ifa);
void ifa_ref(struct ifaddr *ifa);
#endif /* _KERNEL */
2002-12-18 11:46:59 +00:00
/*
* Multicast address structure. This is analogous to the ifaddr
* structure except that it keeps track of multicast addresses.
*/
struct ifmultiaddr {
TAILQ_ENTRY(ifmultiaddr) ifma_link; /* queue macro glue */
struct sockaddr *ifma_addr; /* address this membership is for */
struct sockaddr *ifma_lladdr; /* link-layer translation, if any */
struct ifnet *ifma_ifp; /* back-pointer to interface */
u_int ifma_refcount; /* reference count */
void *ifma_protospec; /* protocol-specific state, if any */
struct ifmultiaddr *ifma_llifma; /* pointer to ifma for ifma_lladdr */
};
#ifdef _KERNEL
extern struct rwlock ifnet_rwlock;
extern struct sx ifnet_sxlock;
#define IFNET_LOCK_INIT() do { \
rw_init_flags(&ifnet_rwlock, "ifnet_rw", RW_RECURSE); \
sx_init_flags(&ifnet_sxlock, "ifnet_sx", SX_RECURSE); \
} while(0)
#define IFNET_WLOCK() do { \
sx_xlock(&ifnet_sxlock); \
rw_wlock(&ifnet_rwlock); \
} while (0)
#define IFNET_WUNLOCK() do { \
rw_wunlock(&ifnet_rwlock); \
sx_xunlock(&ifnet_sxlock); \
} while (0)
/*
* To assert the ifnet lock, you must know not only whether it's for read or
* write, but also whether it was acquired with sleep support or not.
*/
#define IFNET_RLOCK_ASSERT() sx_assert(&ifnet_sxlock, SA_SLOCKED)
#define IFNET_RLOCK_NOSLEEP_ASSERT() rw_assert(&ifnet_rwlock, RA_RLOCKED)
#define IFNET_WLOCK_ASSERT() do { \
sx_assert(&ifnet_sxlock, SA_XLOCKED); \
rw_assert(&ifnet_rwlock, RA_WLOCKED); \
} while (0)
#define IFNET_RLOCK() sx_slock(&ifnet_sxlock)
#define IFNET_RLOCK_NOSLEEP() rw_rlock(&ifnet_rwlock)
#define IFNET_RUNLOCK() sx_sunlock(&ifnet_sxlock)
#define IFNET_RUNLOCK_NOSLEEP() rw_runlock(&ifnet_rwlock)
2002-12-22 05:35:03 +00:00
Start to address a number of races relating to use of ifnet pointers after the corresponding interface has been destroyed: (1) Add an ifnet refcount, ifp->if_refcount. Initialize it to 1 in if_alloc(), and modify if_free_type() to decrement and check the refcount. (2) Add new if_ref() and if_rele() interfaces to allow kernel code walking global interface lists to release IFNET_[RW]LOCK() yet keep the ifnet stable. Currently, if_rele() is a no-op wrapper around if_free(), but this may change in the future. (3) Add new ifnet field, if_alloctype, which caches the type passed to if_alloc(), but unlike if_type, won't be changed by drivers. This allows asynchronous free's of the interface after the driver has released it to still use the right type. Use that instead of the type passed to if_free_type(), but assert that they are the same (might have to rethink this if that doesn't work out). (4) Add a new ifnet_byindex_ref(), which looks up an interface by index and returns a reference rather than a pointer to it. (5) Fix if_alloc() to fully initialize the if_addr_mtx before hooking up the ifnet to global lists. (6) Modify sysctls in if_mib.c to use ifnet_byindex_ref() and release the ifnet when done. When this change is MFC'd, it will need to replace if_ispare fields rather than adding new fields in order to avoid breaking the binary interface. Once this change is MFC'd, if_free_type() should be removed, as its 'type' argument is now optional. This refcount is not appropriate for counting mbuf pkthdr references, and also not for counting entry into the device driver via ifnet function pointers. An rmlock may be appropriate for the latter. Rather, this is about ensuring data structure stability when reaching an ifnet via global ifnet lists and tables followed by copy in or out of userspace. MFC after: 3 weeks Reported by: mdtancsa Reviewed by: brooks
2009-04-21 22:43:32 +00:00
/*
* Look up an ifnet given its index; the _ref variant also acquires a
* reference that must be freed using if_rele(). It is almost always a bug
* to call ifnet_byindex() instead if ifnet_byindex_ref().
*/
struct ifnet *ifnet_byindex(u_short idx);
Change the curvnet variable from a global const struct vnet *, previously always pointing to the default vnet context, to a dynamically changing thread-local one. The currvnet context should be set on entry to networking code via CURVNET_SET() macros, and reverted to previous state via CURVNET_RESTORE(). Recursions on curvnet are permitted, though strongly discuouraged. This change should have no functional impact on nooptions VIMAGE kernel builds, where CURVNET_* macros expand to whitespace. The curthread->td_vnet (aka curvnet) variable's purpose is to be an indicator of the vnet context in which the current network-related operation takes place, in case we cannot deduce the current vnet context from any other source, such as by looking at mbuf's m->m_pkthdr.rcvif->if_vnet, sockets's so->so_vnet etc. Moreover, so far curvnet has turned out to be an invaluable consistency checking aid: it helps to catch cases when sockets, ifnets or any other vnet-aware structures may have leaked from one vnet to another. The exact placement of the CURVNET_SET() / CURVNET_RESTORE() macros was a result of an empirical iterative process, whith an aim to reduce recursions on CURVNET_SET() to a minimum, while still reducing the scope of CURVNET_SET() to networking only operations - the alternative would be calling CURVNET_SET() on each system call entry. In general, curvnet has to be set in three typicall cases: when processing socket-related requests from userspace or from within the kernel; when processing inbound traffic flowing from device drivers to upper layers of the networking stack, and when executing timer-driven networking functions. This change also introduces a DDB subcommand to show the list of all vnet instances. Approved by: julian (mentor)
2009-05-05 10:56:12 +00:00
struct ifnet *ifnet_byindex_locked(u_short idx);
Start to address a number of races relating to use of ifnet pointers after the corresponding interface has been destroyed: (1) Add an ifnet refcount, ifp->if_refcount. Initialize it to 1 in if_alloc(), and modify if_free_type() to decrement and check the refcount. (2) Add new if_ref() and if_rele() interfaces to allow kernel code walking global interface lists to release IFNET_[RW]LOCK() yet keep the ifnet stable. Currently, if_rele() is a no-op wrapper around if_free(), but this may change in the future. (3) Add new ifnet field, if_alloctype, which caches the type passed to if_alloc(), but unlike if_type, won't be changed by drivers. This allows asynchronous free's of the interface after the driver has released it to still use the right type. Use that instead of the type passed to if_free_type(), but assert that they are the same (might have to rethink this if that doesn't work out). (4) Add a new ifnet_byindex_ref(), which looks up an interface by index and returns a reference rather than a pointer to it. (5) Fix if_alloc() to fully initialize the if_addr_mtx before hooking up the ifnet to global lists. (6) Modify sysctls in if_mib.c to use ifnet_byindex_ref() and release the ifnet when done. When this change is MFC'd, it will need to replace if_ispare fields rather than adding new fields in order to avoid breaking the binary interface. Once this change is MFC'd, if_free_type() should be removed, as its 'type' argument is now optional. This refcount is not appropriate for counting mbuf pkthdr references, and also not for counting entry into the device driver via ifnet function pointers. An rmlock may be appropriate for the latter. Rather, this is about ensuring data structure stability when reaching an ifnet via global ifnet lists and tables followed by copy in or out of userspace. MFC after: 3 weeks Reported by: mdtancsa Reviewed by: brooks
2009-04-21 22:43:32 +00:00
struct ifnet *ifnet_byindex_ref(u_short idx);
2008-08-20 03:14:48 +00:00
/*
* Given the index, ifaddr_byindex() returns the one and only
* link-level ifaddr for the interface. You are not supposed to use
* it to traverse the list of addresses associated to the interface.
*/
struct ifaddr *ifaddr_byindex(u_short idx);
Build on Jeff Roberson's linker-set based dynamic per-CPU allocator (DPCPU), as suggested by Peter Wemm, and implement a new per-virtual network stack memory allocator. Modify vnet to use the allocator instead of monolithic global container structures (vinet, ...). This change solves many binary compatibility problems associated with VIMAGE, and restores ELF symbols for virtualized global variables. Each virtualized global variable exists as a "reference copy", and also once per virtual network stack. Virtualized global variables are tagged at compile-time, placing the in a special linker set, which is loaded into a contiguous region of kernel memory. Virtualized global variables in the base kernel are linked as normal, but those in modules are copied and relocated to a reserved portion of the kernel's vnet region with the help of a the kernel linker. Virtualized global variables exist in per-vnet memory set up when the network stack instance is created, and are initialized statically from the reference copy. Run-time access occurs via an accessor macro, which converts from the current vnet and requested symbol to a per-vnet address. When "options VIMAGE" is not compiled into the kernel, normal global ELF symbols will be used instead and indirection is avoided. This change restores static initialization for network stack global variables, restores support for non-global symbols and types, eliminates the need for many subsystem constructors, eliminates large per-subsystem structures that caused many binary compatibility issues both for monitoring applications (netstat) and kernel modules, removes the per-function INIT_VNET_*() macros throughout the stack, eliminates the need for vnet_symmap ksym(2) munging, and eliminates duplicate definitions of virtualized globals under VIMAGE_GLOBALS. Bump __FreeBSD_version and update UPDATING. Portions submitted by: bz Reviewed by: bz, zec Discussed with: gnn, jamie, jeff, jhb, julian, sam Suggested by: peter Approved by: re (kensmith)
2009-07-14 22:48:30 +00:00
VNET_DECLARE(struct ifnethead, ifnet);
VNET_DECLARE(struct ifgrouphead, ifg_head);
VNET_DECLARE(int, if_index);
VNET_DECLARE(struct ifnet *, loif); /* first loopback interface */
#define V_ifnet VNET(ifnet)
#define V_ifg_head VNET(ifg_head)
#define V_if_index VNET(if_index)
#define V_loif VNET(loif)
Build on Jeff Roberson's linker-set based dynamic per-CPU allocator (DPCPU), as suggested by Peter Wemm, and implement a new per-virtual network stack memory allocator. Modify vnet to use the allocator instead of monolithic global container structures (vinet, ...). This change solves many binary compatibility problems associated with VIMAGE, and restores ELF symbols for virtualized global variables. Each virtualized global variable exists as a "reference copy", and also once per virtual network stack. Virtualized global variables are tagged at compile-time, placing the in a special linker set, which is loaded into a contiguous region of kernel memory. Virtualized global variables in the base kernel are linked as normal, but those in modules are copied and relocated to a reserved portion of the kernel's vnet region with the help of a the kernel linker. Virtualized global variables exist in per-vnet memory set up when the network stack instance is created, and are initialized statically from the reference copy. Run-time access occurs via an accessor macro, which converts from the current vnet and requested symbol to a per-vnet address. When "options VIMAGE" is not compiled into the kernel, normal global ELF symbols will be used instead and indirection is avoided. This change restores static initialization for network stack global variables, restores support for non-global symbols and types, eliminates the need for many subsystem constructors, eliminates large per-subsystem structures that caused many binary compatibility issues both for monitoring applications (netstat) and kernel modules, removes the per-function INIT_VNET_*() macros throughout the stack, eliminates the need for vnet_symmap ksym(2) munging, and eliminates duplicate definitions of virtualized globals under VIMAGE_GLOBALS. Bump __FreeBSD_version and update UPDATING. Portions submitted by: bz Reviewed by: bz, zec Discussed with: gnn, jamie, jeff, jhb, julian, sam Suggested by: peter Approved by: re (kensmith)
2009-07-14 22:48:30 +00:00
int if_addgroup(struct ifnet *, const char *);
int if_delgroup(struct ifnet *, const char *);
2002-03-19 21:54:18 +00:00
int if_addmulti(struct ifnet *, struct sockaddr *, struct ifmultiaddr **);
int if_allmulti(struct ifnet *, int);
struct ifnet* if_alloc(u_char);
2002-03-19 21:54:18 +00:00
void if_attach(struct ifnet *);
void if_dead(struct ifnet *);
2002-03-19 21:54:18 +00:00
int if_delmulti(struct ifnet *, struct sockaddr *);
void if_delmulti_ifma(struct ifmultiaddr *);
2002-03-19 21:54:18 +00:00
void if_detach(struct ifnet *);
void if_vmove(struct ifnet *, struct vnet *);
void if_purgeaddrs(struct ifnet *);
void if_delallmulti(struct ifnet *);
2002-03-19 21:54:18 +00:00
void if_down(struct ifnet *);
struct ifmultiaddr *
if_findmulti(struct ifnet *, struct sockaddr *);
void if_free(struct ifnet *);
void if_initname(struct ifnet *, const char *, int);
void if_link_state_change(struct ifnet *, int);
int if_printf(struct ifnet *, const char *, ...) __printflike(2, 3);
Start to address a number of races relating to use of ifnet pointers after the corresponding interface has been destroyed: (1) Add an ifnet refcount, ifp->if_refcount. Initialize it to 1 in if_alloc(), and modify if_free_type() to decrement and check the refcount. (2) Add new if_ref() and if_rele() interfaces to allow kernel code walking global interface lists to release IFNET_[RW]LOCK() yet keep the ifnet stable. Currently, if_rele() is a no-op wrapper around if_free(), but this may change in the future. (3) Add new ifnet field, if_alloctype, which caches the type passed to if_alloc(), but unlike if_type, won't be changed by drivers. This allows asynchronous free's of the interface after the driver has released it to still use the right type. Use that instead of the type passed to if_free_type(), but assert that they are the same (might have to rethink this if that doesn't work out). (4) Add a new ifnet_byindex_ref(), which looks up an interface by index and returns a reference rather than a pointer to it. (5) Fix if_alloc() to fully initialize the if_addr_mtx before hooking up the ifnet to global lists. (6) Modify sysctls in if_mib.c to use ifnet_byindex_ref() and release the ifnet when done. When this change is MFC'd, it will need to replace if_ispare fields rather than adding new fields in order to avoid breaking the binary interface. Once this change is MFC'd, if_free_type() should be removed, as its 'type' argument is now optional. This refcount is not appropriate for counting mbuf pkthdr references, and also not for counting entry into the device driver via ifnet function pointers. An rmlock may be appropriate for the latter. Rather, this is about ensuring data structure stability when reaching an ifnet via global ifnet lists and tables followed by copy in or out of userspace. MFC after: 3 weeks Reported by: mdtancsa Reviewed by: brooks
2009-04-21 22:43:32 +00:00
void if_ref(struct ifnet *);
void if_rele(struct ifnet *);
2002-03-19 21:54:18 +00:00
int if_setlladdr(struct ifnet *, const u_char *, int);
void if_up(struct ifnet *);
int ifioctl(struct socket *, u_long, caddr_t, struct thread *);
int ifpromisc(struct ifnet *, int);
struct ifnet *ifunit(const char *);
struct ifnet *ifunit_ref(const char *);
2002-03-19 21:54:18 +00:00
int ifa_add_loopback_route(struct ifaddr *, struct sockaddr *);
int ifa_del_loopback_route(struct ifaddr *, struct sockaddr *);
int ifa_switch_loopback_route(struct ifaddr *, struct sockaddr *);
2002-03-19 21:54:18 +00:00
struct ifaddr *ifa_ifwithaddr(struct sockaddr *);
int ifa_ifwithaddr_check(struct sockaddr *);
struct ifaddr *ifa_ifwithbroadaddr(struct sockaddr *);
2002-03-19 21:54:18 +00:00
struct ifaddr *ifa_ifwithdstaddr(struct sockaddr *);
struct ifaddr *ifa_ifwithnet(struct sockaddr *, int);
2002-03-19 21:54:18 +00:00
struct ifaddr *ifa_ifwithroute(int, struct sockaddr *, struct sockaddr *);
Add code to allow the system to handle multiple routing tables. This particular implementation is designed to be fully backwards compatible and to be MFC-able to 7.x (and 6.x) Currently the only protocol that can make use of the multiple tables is IPv4 Similar functionality exists in OpenBSD and Linux. From my notes: ----- One thing where FreeBSD has been falling behind, and which by chance I have some time to work on is "policy based routing", which allows different packet streams to be routed by more than just the destination address. Constraints: ------------ I want to make some form of this available in the 6.x tree (and by extension 7.x) , but FreeBSD in general needs it so I might as well do it in -current and back port the portions I need. One of the ways that this can be done is to have the ability to instantiate multiple kernel routing tables (which I will now refer to as "Forwarding Information Bases" or "FIBs" for political correctness reasons). Which FIB a particular packet uses to make the next hop decision can be decided by a number of mechanisms. The policies these mechanisms implement are the "Policies" referred to in "Policy based routing". One of the constraints I have if I try to back port this work to 6.x is that it must be implemented as a EXTENSION to the existing ABIs in 6.x so that third party applications do not need to be recompiled in timespan of the branch. This first version will not have some of the bells and whistles that will come with later versions. It will, for example, be limited to 16 tables in the first commit. Implementation method, Compatible version. (part 1) ------------------------------- For this reason I have implemented a "sufficient subset" of a multiple routing table solution in Perforce, and back-ported it to 6.x. (also in Perforce though not always caught up with what I have done in -current/P4). The subset allows a number of FIBs to be defined at compile time (8 is sufficient for my purposes in 6.x) and implements the changes needed to allow IPV4 to use them. I have not done the changes for ipv6 simply because I do not need it, and I do not have enough knowledge of ipv6 (e.g. neighbor discovery) needed to do it. Other protocol families are left untouched and should there be users with proprietary protocol families, they should continue to work and be oblivious to the existence of the extra FIBs. To understand how this is done, one must know that the current FIB code starts everything off with a single dimensional array of pointers to FIB head structures (One per protocol family), each of which in turn points to the trie of routes available to that family. The basic change in the ABI compatible version of the change is to extent that array to be a 2 dimensional array, so that instead of protocol family X looking at rt_tables[X] for the table it needs, it looks at rt_tables[Y][X] when for all protocol families except ipv4 Y is always 0. Code that is unaware of the change always just sees the first row of the table, which of course looks just like the one dimensional array that existed before. The entry points rtrequest(), rtalloc(), rtalloc1(), rtalloc_ign() are all maintained, but refer only to the first row of the array, so that existing callers in proprietary protocols can continue to do the "right thing". Some new entry points are added, for the exclusive use of ipv4 code called in_rtrequest(), in_rtalloc(), in_rtalloc1() and in_rtalloc_ign(), which have an extra argument which refers the code to the correct row. In addition, there are some new entry points (currently called rtalloc_fib() and friends) that check the Address family being looked up and call either rtalloc() (and friends) if the protocol is not IPv4 forcing the action to row 0 or to the appropriate row if it IS IPv4 (and that info is available). These are for calling from code that is not specific to any particular protocol. The way these are implemented would change in the non ABI preserving code to be added later. One feature of the first version of the code is that for ipv4, the interface routes show up automatically on all the FIBs, so that no matter what FIB you select you always have the basic direct attached hosts available to you. (rtinit() does this automatically). You CAN delete an interface route from one FIB should you want to but by default it's there. ARP information is also available in each FIB. It's assumed that the same machine would have the same MAC address, regardless of which FIB you are using to get to it. This brings us as to how the correct FIB is selected for an outgoing IPV4 packet. Firstly, all packets have a FIB associated with them. if nothing has been done to change it, it will be FIB 0. The FIB is changed in the following ways. Packets fall into one of a number of classes. 1/ locally generated packets, coming from a socket/PCB. Such packets select a FIB from a number associated with the socket/PCB. This in turn is inherited from the process, but can be changed by a socket option. The process in turn inherits it on fork. I have written a utility call setfib that acts a bit like nice.. setfib -3 ping target.example.com # will use fib 3 for ping. It is an obvious extension to make it a property of a jail but I have not done so. It can be achieved by combining the setfib and jail commands. 2/ packets received on an interface for forwarding. By default these packets would use table 0, (or possibly a number settable in a sysctl(not yet)). but prior to routing the firewall can inspect them (see below). (possibly in the future you may be able to associate a FIB with packets received on an interface.. An ifconfig arg, but not yet.) 3/ packets inspected by a packet classifier, which can arbitrarily associate a fib with it on a packet by packet basis. A fib assigned to a packet by a packet classifier (such as ipfw) would over-ride a fib associated by a more default source. (such as cases 1 or 2). 4/ a tcp listen socket associated with a fib will generate accept sockets that are associated with that same fib. 5/ Packets generated in response to some other packet (e.g. reset or icmp packets). These should use the FIB associated with the packet being reponded to. 6/ Packets generated during encapsulation. gif, tun and other tunnel interfaces will encapsulate using the FIB that was in effect withthe proces that set up the tunnel. thus setfib 1 ifconfig gif0 [tunnel instructions] will set the fib for the tunnel to use to be fib 1. Routing messages would be associated with their process, and thus select one FIB or another. messages from the kernel would be associated with the fib they refer to and would only be received by a routing socket associated with that fib. (not yet implemented) In addition Netstat has been edited to be able to cope with the fact that the array is now 2 dimensional. (It looks in system memory using libkvm (!)). Old versions of netstat see only the first FIB. In addition two sysctls are added to give: a) the number of FIBs compiled in (active) b) the default FIB of the calling process. Early testing experience: ------------------------- Basically our (IronPort's) appliance does this functionality already using ipfw fwd but that method has some drawbacks. For example, It can't fully simulate a routing table because it can't influence the socket's choice of local address when a connect() is done. Testing during the generating of these changes has been remarkably smooth so far. Multiple tables have co-existed with no notable side effects, and packets have been routes accordingly. ipfw has grown 2 new keywords: setfib N ip from anay to any count ip from any to any fib N In pf there seems to be a requirement to be able to give symbolic names to the fibs but I do not have that capacity. I am not sure if it is required. SCTP has interestingly enough built in support for this, called VRFs in Cisco parlance. it will be interesting to see how that handles it when it suddenly actually does something. Where to next: -------------------- After committing the ABI compatible version and MFCing it, I'd like to proceed in a forward direction in -current. this will result in some roto-tilling in the routing code. Firstly: the current code's idea of having a separate tree per protocol family, all of the same format, and pointed to by the 1 dimensional array is a bit silly. Especially when one considers that there is code that makes assumptions about every protocol having the same internal structures there. Some protocols don't WANT that sort of structure. (for example the whole idea of a netmask is foreign to appletalk). This needs to be made opaque to the external code. My suggested first change is to add routing method pointers to the 'domain' structure, along with information pointing the data. instead of having an array of pointers to uniform structures, there would be an array pointing to the 'domain' structures for each protocol address domain (protocol family), and the methods this reached would be called. The methods would have an argument that gives FIB number, but the protocol would be free to ignore it. When the ABI can be changed it raises the possibilty of the addition of a fib entry into the "struct route". Currently, the structure contains the sockaddr of the desination, and the resulting fib entry. To make this work fully, one could add a fib number so that given an address and a fib, one can find the third element, the fib entry. Interaction with the ARP layer/ LL layer would need to be revisited as well. Qing Li has been working on this already. This work was sponsored by Ironport Systems/Cisco Reviewed by: several including rwatson, bz and mlair (parts each) Obtained from: Ironport systems/Cisco
2008-05-09 23:03:00 +00:00
struct ifaddr *ifa_ifwithroute_fib(int, struct sockaddr *, struct sockaddr *, u_int);
2002-03-19 21:54:18 +00:00
struct ifaddr *ifaof_ifpforaddr(struct sockaddr *, struct ifnet *);
int ifa_preferred(struct ifaddr *, struct ifaddr *);
2002-03-19 21:54:18 +00:00
int if_simloop(struct ifnet *ifp, struct mbuf *m, int af, int hlen);
typedef void *if_com_alloc_t(u_char type, struct ifnet *ifp);
typedef void if_com_free_t(void *com, u_char type);
void if_register_com_alloc(u_char type, if_com_alloc_t *a, if_com_free_t *f);
void if_deregister_com_alloc(u_char type);
#define IF_LLADDR(ifp) \
LLADDR((struct sockaddr_dl *)((ifp)->if_addr->ifa_addr))
#endif /* _KERNEL */
#endif /* !_NET_IF_VAR_H_ */