Author: cem Date: Fri May 10 23:12:59 2019 New Revision: 347473 URL: https://svnweb.freebsd.org/changeset/base/347473
Log: netdump: Ref the interface we're attached to Serialize netdump configuration / deconfiguration, and discard our configuration when the affiliated interface goes away by monitoring ifnet_departure_event. Reviewed by: markj, with input from vangyzen@ (earlier version) Sponsored by: Dell EMC Isilon Differential Revision: https://reviews.freebsd.org/D20206 Modified: head/sys/netinet/netdump/netdump_client.c Modified: head/sys/netinet/netdump/netdump_client.c ============================================================================== --- head/sys/netinet/netdump/netdump_client.c Fri May 10 23:12:37 2019 (r347472) +++ head/sys/netinet/netdump/netdump_client.c Fri May 10 23:12:59 2019 (r347473) @@ -93,6 +93,8 @@ static int netdump_configure(struct diocskerneldump_a struct thread *); static int netdump_dumper(void *priv __unused, void *virtual, vm_offset_t physical __unused, off_t offset, size_t length); +static bool netdump_enabled(void); +static int netdump_enabled_sysctl(SYSCTL_HANDLER_ARGS); static int netdump_ether_output(struct mbuf *m, struct ifnet *ifp, struct ether_addr dst, u_short etype); static void netdump_handle_arp(struct mbuf **mb); @@ -102,11 +104,13 @@ static int netdump_ioctl(struct cdev *dev __unused, u static int netdump_modevent(module_t mod, int type, void *priv); static void netdump_network_poll(void); static void netdump_pkt_in(struct ifnet *ifp, struct mbuf *m); +static void netdump_reinit_internal(struct ifnet *ifp); static int netdump_send(uint32_t type, off_t offset, unsigned char *data, uint32_t datalen); static int netdump_send_arp(in_addr_t dst); static int netdump_start(struct dumperinfo *di); static int netdump_udp_output(struct mbuf *m); +static void netdump_unconfigure(void); /* Must be at least as big as the chunks dumpsys() gives us. */ static unsigned char nd_buf[MAXDUMPPGS * PAGE_SIZE]; @@ -131,8 +135,17 @@ static struct { #define nd_gateway nd_conf.ndc_gateway.in4 /* General dynamic settings. */ +static struct sx nd_conf_lk; +SX_SYSINIT(nd_conf, &nd_conf_lk, "netdump configuration lock"); +#define NETDUMP_WLOCK() sx_xlock(&nd_conf_lk) +#define NETDUMP_WUNLOCK() sx_xunlock(&nd_conf_lk) +#define NETDUMP_RLOCK() sx_slock(&nd_conf_lk) +#define NETDUMP_RUNLOCK() sx_sunlock(&nd_conf_lk) +#define NETDUMP_ASSERT_WLOCKED() sx_assert(&nd_conf_lk, SA_XLOCKED) +#define NETDUMP_ASSERT_LOCKED() sx_assert(&nd_conf_lk, SA_LOCKED) static struct ether_addr nd_gw_mac; static struct ifnet *nd_ifp; +static eventhandler_tag nd_detach_cookie; static uint16_t nd_server_port = NETDUMP_PORT; FEATURE(netdump, "Netdump client support"); @@ -144,10 +157,8 @@ static int nd_debug; SYSCTL_INT(_net_netdump, OID_AUTO, debug, CTLFLAG_RWTUN, &nd_debug, 0, "Debug message verbosity"); -static int nd_enabled; -SYSCTL_INT(_net_netdump, OID_AUTO, enabled, CTLFLAG_RD, - &nd_enabled, 0, - "netdump configuration status"); +SYSCTL_PROC(_net_netdump, OID_AUTO, enabled, CTLFLAG_RD | CTLTYPE_INT, + &nd_ifp, 0, netdump_enabled_sysctl, "I", "netdump configuration status"); static char nd_path[MAXPATHLEN]; SYSCTL_STRING(_net_netdump, OID_AUTO, path, CTLFLAG_RW, nd_path, sizeof(nd_path), @@ -165,6 +176,29 @@ SYSCTL_INT(_net_netdump, OID_AUTO, arp_retries, CTLFLA &nd_arp_retries, 0, "Number of ARP attempts before giving up"); +static bool +netdump_enabled(void) +{ + + NETDUMP_ASSERT_LOCKED(); + return (nd_ifp != NULL); +} + +static int +netdump_enabled_sysctl(SYSCTL_HANDLER_ARGS) +{ + int en, error; + + NETDUMP_RLOCK(); + en = netdump_enabled(); + NETDUMP_RUNLOCK(); + + error = SYSCTL_OUT(req, &en, sizeof(en)); + if (error != 0 || req->newptr == NULL) + return (error); + return (EPERM); +} + /* * Checks for netdump support on a network interface * @@ -248,7 +282,7 @@ netdump_udp_output(struct mbuf *m) struct udpiphdr *ui; struct ip *ip; - MPASS(nd_ifp != NULL); + MPASS(netdump_enabled()); M_PREPEND(m, sizeof(struct udpiphdr), M_NOWAIT); if (m == NULL) { @@ -306,7 +340,7 @@ netdump_send_arp(in_addr_t dst) struct arphdr *ah; int pktlen; - MPASS(nd_ifp != NULL); + MPASS(netdump_enabled()); /* Fill-up a broadcast address. */ memset(&bcast, 0xFF, ETHER_ADDR_LEN); @@ -409,7 +443,7 @@ netdump_send(uint32_t type, off_t offset, unsigned cha rcvd_acks = 0; retries = 0; - MPASS(nd_ifp != NULL); + MPASS(netdump_enabled()); retransmit: /* Chunks can be too big to fit in packets. */ @@ -875,7 +909,7 @@ static void netdump_network_poll(void) { - MPASS(nd_ifp != NULL); + MPASS(netdump_enabled()); nd_ifp->if_netdump_methods->nd_poll(nd_ifp, 1000); } @@ -945,7 +979,7 @@ netdump_start(struct dumperinfo *di) error = 0; /* Check if the dumping is allowed to continue. */ - if (nd_enabled == 0) + if (!netdump_enabled()) return (EINVAL); if (panicstr == NULL) { @@ -954,8 +988,6 @@ netdump_start(struct dumperinfo *di) return (EINVAL); } - MPASS(nd_ifp != NULL); - if (nd_server.s_addr == INADDR_ANY) { printf("netdump_start: can't netdump; no server IP given\n"); return (EINVAL); @@ -1065,36 +1097,68 @@ static struct cdevsw netdump_cdevsw = { static struct cdev *netdump_cdev; +static void +netdump_unconfigure(void) +{ + struct diocskerneldump_arg kda; + + NETDUMP_ASSERT_WLOCKED(); + KASSERT(netdump_enabled(), ("%s: nd_ifp NULL", __func__)); + + bzero(&kda, sizeof(kda)); + kda.kda_index = KDA_REMOVE_DEV; + (void)dumper_remove(nd_conf.ndc_iface, &kda); + + netdump_mbuf_drain(); + + if_rele(nd_ifp); + nd_ifp = NULL; + + bzero(&nd_conf, sizeof(nd_conf)); +} + +static void +netdump_ifdetach(void *arg __unused, struct ifnet *ifp) +{ + + NETDUMP_WLOCK(); + if (ifp == nd_ifp) + netdump_unconfigure(); + NETDUMP_WUNLOCK(); +} + static int netdump_configure(struct diocskerneldump_arg *conf, struct thread *td) { - struct epoch_tracker et; struct ifnet *ifp; + NETDUMP_ASSERT_WLOCKED(); + CURVNET_SET(TD_TO_VNET(td)); if (!IS_DEFAULT_VNET(curvnet)) { CURVNET_RESTORE(); return (EINVAL); } - NET_EPOCH_ENTER(et); - CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) { - if (strcmp(ifp->if_xname, conf->kda_iface) == 0) - break; - } - /* XXX ref */ - NET_EPOCH_EXIT(et); + ifp = ifunit_ref(conf->kda_iface); CURVNET_RESTORE(); if (ifp == NULL) return (ENOENT); - if ((if_getflags(ifp) & IFF_UP) == 0) + if ((if_getflags(ifp) & IFF_UP) == 0) { + if_rele(ifp); return (ENXIO); - if (!netdump_supported_nic(ifp) || ifp->if_type != IFT_ETHER) + } + if (!netdump_supported_nic(ifp) || ifp->if_type != IFT_ETHER) { + if_rele(ifp); return (ENODEV); + } + if (netdump_enabled()) + if_rele(nd_ifp); nd_ifp = ifp; - netdump_reinit(ifp); + netdump_reinit_internal(ifp); + #define COPY_SIZED(elm) do { \ _Static_assert(sizeof(nd_conf.ndc_ ## elm) == \ sizeof(conf->kda_ ## elm), "elm " __XSTRING(elm) " mismatch"); \ @@ -1107,23 +1171,35 @@ netdump_configure(struct diocskerneldump_arg *conf, st COPY_SIZED(gateway); COPY_SIZED(af); #undef COPY_SIZED - nd_enabled = 1; + return (0); } /* * Reinitialize the mbuf pool used by drivers while dumping. This is called - * from the generic ioctl handler for SIOCSIFMTU after the driver has - * reconfigured itself. + * from the generic ioctl handler for SIOCSIFMTU after any NIC driver has + * reconfigured itself. (I.e., it may not be a configured netdump interface.) */ void netdump_reinit(struct ifnet *ifp) { - int clsize, nmbuf, ncl, nrxr; - if (ifp != nd_ifp) + NETDUMP_WLOCK(); + if (ifp != nd_ifp) { + NETDUMP_WUNLOCK(); return; + } + netdump_reinit_internal(ifp); + NETDUMP_WUNLOCK(); +} +static void +netdump_reinit_internal(struct ifnet *ifp) +{ + int clsize, nmbuf, ncl, nrxr; + + NETDUMP_ASSERT_WLOCKED(); + ifp->if_netdump_methods->nd_init(ifp, &nrxr, &ncl, &clsize); KASSERT(nrxr > 0, ("invalid receive ring count %d", nrxr)); @@ -1168,6 +1244,8 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, c conf = NULL; error = 0; + NETDUMP_WLOCK(); + switch (cmd) { #ifdef COMPAT_FREEBSD11 case DIOCSKERNELDUMP_FREEBSD11: @@ -1177,10 +1255,8 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, c error = ENXIO; break; } - if (nd_enabled) { - nd_enabled = 0; - netdump_mbuf_drain(); - } + if (netdump_enabled()) + netdump_unconfigure(); break; #endif #ifdef COMPAT_FREEBSD12 @@ -1197,17 +1273,15 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, c error = ENXIO; break; } - if (nd_enabled) { - nd_enabled = 0; - netdump_mbuf_drain(); - } + if (netdump_enabled()) + netdump_unconfigure(); break; case NETDUMPGCONF_FREEBSD12: gone_in(14, "FreeBSD 12.x ABI compat"); conf12 = (void *)addr; - if (!nd_enabled) { + if (!netdump_enabled()) { error = ENXIO; break; } @@ -1232,7 +1306,7 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, c * For now, index is ignored; netdump doesn't support multiple * configurations (yet). */ - if (!nd_enabled) { + if (!netdump_enabled()) { error = ENXIO; conf = NULL; break; @@ -1293,13 +1367,10 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, c if (conf->kda_index == KDA_REMOVE || conf->kda_index == KDA_REMOVE_DEV || conf->kda_index == KDA_REMOVE_ALL) { - if (nd_enabled || conf->kda_index == KDA_REMOVE_ALL) { - error = dumper_remove(conf->kda_iface, conf); - if (error == 0) { - nd_enabled = 0; - netdump_mbuf_drain(); - } - } + if (netdump_enabled()) + netdump_unconfigure(); + if (conf->kda_index == KDA_REMOVE_ALL) + error = dumper_remove(NULL, conf); break; } @@ -1342,10 +1413,8 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, c conf->kda_encryptedkeysize); free(encryptedkey, M_TEMP); } - if (error != 0) { - nd_enabled = 0; - netdump_mbuf_drain(); - } + if (error != 0) + netdump_unconfigure(); break; default: error = ENOTTY; @@ -1354,6 +1423,7 @@ netdump_ioctl(struct cdev *dev __unused, u_long cmd, c explicit_bzero(&kda_copy, sizeof(kda_copy)); if (conf != NULL) explicit_bzero(conf, sizeof(*conf)); + NETDUMP_WUNLOCK(); return (error); } @@ -1385,6 +1455,9 @@ netdump_modevent(module_t mod __unused, int what, void if (error != 0) return (error); + nd_detach_cookie = EVENTHANDLER_REGISTER(ifnet_departure_event, + netdump_ifdetach, NULL, EVENTHANDLER_PRI_ANY); + if ((arg = kern_getenv("net.dump.iface")) != NULL) { strlcpy(conf.kda_iface, arg, sizeof(conf.kda_iface)); freeenv(arg); @@ -1404,23 +1477,21 @@ netdump_modevent(module_t mod __unused, int what, void conf.kda_af = AF_INET; /* Ignore errors; we print a message to the console. */ + NETDUMP_WLOCK(); (void)netdump_configure(&conf, curthread); + NETDUMP_WUNLOCK(); } break; case MOD_UNLOAD: - if (nd_enabled) { - struct diocskerneldump_arg kda; - + NETDUMP_WLOCK(); + if (netdump_enabled()) { printf("netdump: disabling dump device for unload\n"); - - bzero(&kda, sizeof(kda)); - kda.kda_index = KDA_REMOVE_DEV; - (void)dumper_remove(nd_conf.ndc_iface, &kda); - - netdump_mbuf_drain(); - nd_enabled = 0; + netdump_unconfigure(); } + NETDUMP_WUNLOCK(); destroy_dev(netdump_cdev); + EVENTHANDLER_DEREGISTER(ifnet_departure_event, + nd_detach_cookie); break; default: error = EOPNOTSUPP; _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
