Module Name: src
Committed By: ozaki-r
Date: Fri Dec 15 04:06:42 UTC 2017
Modified Files:
src/sys/net: if.h
Log Message:
Describe which lock is used to protect each member variable of struct ifnet
Requested by skrll@
To generate a diff of this commit:
cvs rdiff -u -r1.254 -r1.255 src/sys/net/if.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/net/if.h
diff -u src/sys/net/if.h:1.254 src/sys/net/if.h:1.255
--- src/sys/net/if.h:1.254 Fri Dec 15 04:03:46 2017
+++ src/sys/net/if.h Fri Dec 15 04:06:42 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: if.h,v 1.254 2017/12/15 04:03:46 ozaki-r Exp $ */
+/* $NetBSD: if.h,v 1.255 2017/12/15 04:06:42 ozaki-r Exp $ */
/*-
* Copyright (c) 1999, 2000, 2001 The NetBSD Foundation, Inc.
@@ -235,86 +235,111 @@ struct in6_multi;
typedef unsigned short if_index_t;
+/*
+ * Interface. Field markings and the corresponding locks:
+ *
+ * i: IFNET_LOCK (a.k.a., if_ioctl_lock)
+ * q: ifq_lock (struct ifaltq)
+ * a: if_afdata_lock
+ * 6: in6_multilock (global lock)
+ * :: unlocked, stable
+ * ?: unkown, maybe unsafe
+ *
+ * Lock order: IFNET_LOCK => in6_multilock => if_afdata_lock => ifq_lock
+ * Note that currently if_afdata_lock and ifq_lock aren't held
+ * at the same time, but define the order anyway.
+ *
+ * Lock order of IFNET_LOCK with other locks:
+ * softnet_lock => solock => IFNET_LOCK => ND6_LOCK, in_multilock
+ */
typedef struct ifnet {
- void *if_softc; /* lower-level data for this if */
+ void *if_softc; /* :: lower-level data for this if */
/* DEPRECATED. Keep it to avoid breaking kvm(3) users */
- TAILQ_ENTRY(ifnet) if_list; /* all struct ifnets are chained */
- TAILQ_HEAD(, ifaddr) if_addrlist; /* linked list of addresses per if */
- char if_xname[IFNAMSIZ]; /* external name (name + unit) */
- int if_pcount; /* number of promiscuous listeners */
- struct bpf_if *if_bpf; /* packet filter structure */
- if_index_t if_index; /* numeric abbreviation for this if */
- short if_timer; /* time 'til if_slowtimo called */
- unsigned short if_flags; /* up/down, broadcast, etc. */
- short if_extflags; /* if_output MP-safe, etc. */
- struct if_data if_data; /* statistics and other data about if */
+ TAILQ_ENTRY(ifnet)
+ if_list; /* i: all struct ifnets are chained */
+ TAILQ_HEAD(, ifaddr)
+ if_addrlist; /* i: linked list of addresses per if */
+ char if_xname[IFNAMSIZ];
+ /* :: external name (name + unit) */
+ int if_pcount; /* i: number of promiscuous listeners */
+ struct bpf_if *if_bpf; /* :: packet filter structure */
+ if_index_t if_index; /* :: numeric abbreviation for this if */
+ short if_timer; /* ?: time 'til if_slowtimo called */
+ unsigned short if_flags; /* i: up/down, broadcast, etc. */
+ short if_extflags; /* :: if_output MP-safe, etc. */
+ struct if_data if_data; /* ?: statistics and other data about if */
/*
* Procedure handles. If you add more of these, don't forget the
* corresponding NULL stub in if.c.
*/
- int (*if_output) /* output routine (enqueue) */
- (struct ifnet *, struct mbuf *, const struct sockaddr *,
- const struct rtentry *);
- void (*_if_input) /* input routine (from h/w driver) */
- (struct ifnet *, struct mbuf *);
- void (*if_start) /* initiate output routine */
- (struct ifnet *);
- int (*if_transmit) /* output routine, must be MP-safe */
- (struct ifnet *, struct mbuf *);
- int (*if_ioctl) /* ioctl routine */
- (struct ifnet *, u_long, void *);
- int (*if_init) /* init routine */
- (struct ifnet *);
- void (*if_stop) /* stop routine */
- (struct ifnet *, int);
- void (*if_slowtimo) /* timer routine */
- (struct ifnet *);
+ int (*if_output) /* :: output routine (enqueue) */
+ (struct ifnet *, struct mbuf *, const struct sockaddr *,
+ const struct rtentry *);
+ void (*_if_input) /* :: input routine (from h/w driver) */
+ (struct ifnet *, struct mbuf *);
+ void (*if_start) /* :: initiate output routine */
+ (struct ifnet *);
+ int (*if_transmit) /* :: output routine, must be MP-safe */
+ (struct ifnet *, struct mbuf *);
+ int (*if_ioctl) /* :: ioctl routine */
+ (struct ifnet *, u_long, void *);
+ int (*if_init) /* :: init routine */
+ (struct ifnet *);
+ void (*if_stop) /* :: stop routine */
+ (struct ifnet *, int);
+ void (*if_slowtimo) /* :: timer routine */
+ (struct ifnet *);
#define if_watchdog if_slowtimo
- void (*if_drain) /* routine to release resources */
- (struct ifnet *);
- struct ifaltq if_snd; /* output queue (includes altq) */
- struct ifaddr *if_dl; /* identity of this interface. */
- const struct sockaddr_dl *if_sadl; /* pointer to sockaddr_dl
- * of if_dl
- */
- /* if_hwdl: h/w identity
- *
+ void (*if_drain) /* :: routine to release resources */
+ (struct ifnet *);
+ struct ifaltq if_snd; /* q: output queue (includes altq) */
+ struct ifaddr *if_dl; /* i: identity of this interface. */
+ const struct sockaddr_dl
+ *if_sadl; /* i: pointer to sockaddr_dl of if_dl */
+ /*
* May be NULL. If not NULL, it is the address assigned
* to the interface by the manufacturer, so it very likely
* to be unique. It MUST NOT be deleted. It is highly
* suitable for deriving the EUI64 for the interface.
*/
- struct ifaddr *if_hwdl;
- const uint8_t *if_broadcastaddr;/* linklevel broadcast bytestring */
- struct bridge_softc *if_bridge; /* bridge glue */
- struct bridge_iflist *if_bridgeif; /* shortcut to interface list entry */
- int if_dlt; /* data link type (<net/dlt.h>) */
- pfil_head_t * if_pfil; /* filtering point */
- uint64_t if_capabilities; /* interface capabilities */
- uint64_t if_capenable; /* capabilities enabled */
+ struct ifaddr *if_hwdl; /* i: h/w identity */
+ const uint8_t *if_broadcastaddr;
+ /* :: linklevel broadcast bytestring */
+ struct bridge_softc
+ *if_bridge; /* i: bridge glue */
+ struct bridge_iflist
+ *if_bridgeif; /* i: shortcut to interface list entry */
+ int if_dlt; /* :: data link type (<net/dlt.h>) */
+ pfil_head_t * if_pfil; /* :: filtering point */
+ uint64_t if_capabilities;
+ /* i: interface capabilities */
+ uint64_t if_capenable; /* i: capabilities enabled */
union {
void * carp_s; /* carp structure (used by !carp ifs) */
struct ifnet *carp_d;/* ptr to carpdev (used by carp ifs) */
- } if_carp_ptr;
+ } if_carp_ptr; /* ?: */
#define if_carp if_carp_ptr.carp_s
#define if_carpdev if_carp_ptr.carp_d
/*
* These are pre-computed based on an interfaces enabled
* capabilities, for speed elsewhere.
*/
- int if_csum_flags_tx; /* M_CSUM_* flags for Tx */
- int if_csum_flags_rx; /* M_CSUM_* flags for Rx */
-
- void *if_afdata[AF_MAX];
- struct mowner *if_mowner; /* who owns mbufs for this interface */
+ int if_csum_flags_tx;
+ /* i: M_CSUM_* flags for Tx */
+ int if_csum_flags_rx;
+ /* i: M_CSUM_* flags for Rx */
+
+ void *if_afdata[AF_MAX];
+ /* a: */
+ struct mowner *if_mowner; /* ?: who owns mbufs for this interface */
- void *if_agrprivate; /* used only when #if NAGR > 0 */
+ void *if_agrprivate; /* ?: used only when #if NAGR > 0 */
/*
* pf specific data, used only when #if NPF > 0.
*/
- void *if_pf_kif; /* pf interface abstraction */
- void *if_pf_groups; /* pf interface groups */
+ void *if_pf_kif; /* ?: pf interface abstraction */
+ void *if_pf_groups; /* ?: pf interface groups */
/*
* During an ifnet's lifetime, it has only one if_index, but
* and if_index is not sufficient to identify an ifnet
@@ -324,29 +349,40 @@ typedef struct ifnet {
* is assigned when it if_attach()s. Now, the kernel can use the
* pair (if_index, if_index_gen) as a weak reference to an ifnet.
*/
- uint64_t if_index_gen; /* generation number for the ifnet
+ uint64_t if_index_gen; /* :: generation number for the ifnet
* at if_index: if two ifnets' index
* and generation number are both the
* same, they are the same ifnet.
*/
- struct sysctllog *if_sysctl_log;
- int (*if_initaddr)(struct ifnet *, struct ifaddr *, bool);
- int (*if_mcastop)(struct ifnet *, const unsigned long,
- const struct sockaddr *);
- int (*if_setflags)(struct ifnet *, const short);
- kmutex_t *if_ioctl_lock;
+ struct sysctllog
+ *if_sysctl_log; /* :: */
+ int (*if_initaddr) /* :: */
+ (struct ifnet *, struct ifaddr *, bool);
+ int (*if_mcastop) /* :: */
+ (struct ifnet *, const unsigned long,
+ const struct sockaddr *);
+ int (*if_setflags) /* :: */
+ (struct ifnet *, const short);
+ kmutex_t *if_ioctl_lock; /* :: */
#ifdef _KERNEL /* XXX kvm(3) */
- struct callout *if_slowtimo_ch;
- struct krwlock *if_afdata_lock;
- struct if_percpuq *if_percpuq; /* We should remove it in the future */
- void *if_link_si; /* softint to handle link state changes */
- uint16_t if_link_queue; /* masked link state change queue */
- struct pslist_entry if_pslist_entry;
- struct psref_target if_psref;
- struct pslist_head if_addr_pslist;
- struct if_deferred_start *if_deferred_start;
+ struct callout *if_slowtimo_ch;/* :: */
+ struct krwlock *if_afdata_lock;/* :: */
+ struct if_percpuq
+ *if_percpuq; /* :: we should remove it in the future */
+ void *if_link_si; /* :: softint to handle link state changes */
+ uint16_t if_link_queue; /* q: masked link state change queue */
+ struct pslist_entry
+ if_pslist_entry;/* i: */
+ struct psref_target
+ if_psref; /* :: */
+ struct pslist_head
+ if_addr_pslist; /* i: */
+ struct if_deferred_start
+ *if_deferred_start;
+ /* :: */
/* XXX should be protocol independent */
- LIST_HEAD(, in6_multi) if_multiaddrs;
+ LIST_HEAD(, in6_multi)
+ if_multiaddrs; /* 6: */
#endif
} ifnet_t;
