diff --git a/usr.sbin/rtsold/rtsold.c b/usr.sbin/rtsold/rtsold.c index 5e5298bfdadc..c1594ec7420a 100644 --- a/usr.sbin/rtsold/rtsold.c +++ b/usr.sbin/rtsold/rtsold.c @@ -1,925 +1,922 @@ /* $KAME: rtsold.c,v 1.67 2003/05/17 18:16:15 itojun Exp $ */ /*- * SPDX-License-Identifier: BSD-3-Clause * * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * 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. * 3. Neither the name of the project 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 PROJECT 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 PROJECT 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. * * $FreeBSD$ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "rtsold.h" #define RTSOL_DUMPFILE "/var/run/rtsold.dump" struct timespec tm_max; static int log_upto = 999; static int fflag = 0; int Fflag = 0; /* force setting sysctl parameters */ int aflag = 0; int dflag = 0; int uflag = 0; const char *managedconf_script; const char *otherconf_script; const char *resolvconf_script = "/sbin/resolvconf"; cap_channel_t *capllflags, *capscript, *capsendmsg, *capsyslog; /* protocol constants */ #define MAX_RTR_SOLICITATION_DELAY 1 /* second */ #define RTR_SOLICITATION_INTERVAL 4 /* seconds */ #define MAX_RTR_SOLICITATIONS 3 /* times */ /* * implementation dependent constants in seconds * XXX: should be configurable */ #define PROBE_INTERVAL 60 /* static variables and functions */ static int mobile_node = 0; static sig_atomic_t do_dump, do_exit; static struct pidfh *pfh; static char **autoifprobe(void); static int ifconfig(char *ifname); static int init_capabilities(void); static int make_packet(struct ifinfo *); static struct timespec *rtsol_check_timer(void); static void set_dumpfile(int); static void set_exit(int); static void usage(const char *progname); int main(int argc, char **argv) { struct kevent events[2]; FILE *dumpfp; struct ifinfo *ifi; struct timespec *timeout; const char *opts, *pidfilepath, *progname; int ch, error, kq, once, rcvsock, rtsock; progname = basename(argv[0]); if (strcmp(progname, "rtsold") == 0) { opts = "adDfFm1M:O:p:R:u"; once = 0; pidfilepath = NULL; } else { opts = "adDFM:O:R:u"; fflag = 1; once = 1; } while ((ch = getopt(argc, argv, opts)) != -1) { switch (ch) { case 'a': aflag = 1; break; case 'd': dflag += 1; break; case 'D': dflag += 2; break; case 'f': fflag = 1; break; case 'F': Fflag = 1; break; case 'm': mobile_node = 1; break; case '1': once = 1; break; case 'M': managedconf_script = optarg; break; case 'O': otherconf_script = optarg; break; case 'p': pidfilepath = optarg; break; case 'R': resolvconf_script = optarg; break; case 'u': uflag = 1; break; default: usage(progname); } } argc -= optind; argv += optind; if ((!aflag && argc == 0) || (aflag && argc != 0)) usage(progname); /* Generate maximum time in timespec. */ tm_max.tv_sec = (-1) & ~((time_t)1 << ((sizeof(tm_max.tv_sec) * 8) - 1)); tm_max.tv_nsec = (-1) & ~((long)1 << ((sizeof(tm_max.tv_nsec) * 8) - 1)); /* set log level */ if (dflag > 1) log_upto = LOG_DEBUG; else if (dflag > 0) log_upto = LOG_INFO; else log_upto = LOG_NOTICE; if (managedconf_script != NULL && *managedconf_script != '/') errx(1, "configuration script (%s) must be an absolute path", managedconf_script); if (otherconf_script != NULL && *otherconf_script != '/') errx(1, "configuration script (%s) must be an absolute path", otherconf_script); if (*resolvconf_script != '/') errx(1, "configuration script (%s) must be an absolute path", resolvconf_script); if (!fflag) { pfh = pidfile_open(pidfilepath, 0644, NULL); if (pfh == NULL) errx(1, "failed to open pidfile: %s", strerror(errno)); if (daemon(0, 0) != 0) errx(1, "failed to daemonize"); } if ((error = init_capabilities()) != 0) err(1, "failed to initialize capabilities"); if (!fflag) { cap_openlog(capsyslog, progname, LOG_NDELAY | LOG_PID, LOG_DAEMON); if (log_upto >= 0) (void)cap_setlogmask(capsyslog, LOG_UPTO(log_upto)); (void)signal(SIGTERM, set_exit); (void)signal(SIGINT, set_exit); (void)signal(SIGUSR1, set_dumpfile); dumpfp = rtsold_init_dumpfile(RTSOL_DUMPFILE); } else dumpfp = NULL; kq = kqueue(); if (kq < 0) { warnmsg(LOG_ERR, __func__, "failed to create a kqueue: %s", strerror(errno)); exit(1); } /* Open global sockets and register for read events. */ if ((rtsock = rtsock_open()) < 0) { warnmsg(LOG_ERR, __func__, "failed to open routing socket"); exit(1); } if ((rcvsock = recvsockopen()) < 0) { warnmsg(LOG_ERR, __func__, "failed to open receive socket"); exit(1); } EV_SET(&events[0], rtsock, EVFILT_READ, EV_ADD, 0, 0, NULL); EV_SET(&events[1], rcvsock, EVFILT_READ, EV_ADD, 0, 0, NULL); if (kevent(kq, events, 2, NULL, 0, NULL) < 0) { warnmsg(LOG_ERR, __func__, "kevent(): %s", strerror(errno)); exit(1); } /* Probe network interfaces and set up tracking info. */ if (ifinit() != 0) { warnmsg(LOG_ERR, __func__, "failed to initialize interfaces"); exit(1); } if (aflag) argv = autoifprobe(); while (argv && *argv) { if (ifconfig(*argv)) { warnmsg(LOG_ERR, __func__, "failed to initialize %s", *argv); exit(1); } argv++; } /* Write to our pidfile. */ if (pfh != NULL && pidfile_write(pfh) != 0) { warnmsg(LOG_ERR, __func__, "failed to open pidfile: %s", strerror(errno)); exit(1); } /* Enter capability mode. */ caph_cache_catpages(); if (caph_enter_casper() != 0) { warnmsg(LOG_ERR, __func__, "caph_enter(): %s", strerror(errno)); exit(1); } for (;;) { if (do_exit) { /* Handle SIGTERM, SIGINT. */ if (pfh != NULL) pidfile_remove(pfh); break; } if (do_dump) { /* Handle SIGUSR1. */ do_dump = 0; if (dumpfp != NULL) rtsold_dump(dumpfp); } timeout = rtsol_check_timer(); if (once) { /* if we have no timeout, we are done (or failed) */ if (timeout == NULL) break; /* if all interfaces have got RA packet, we are done */ TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) { if (ifi->state != IFS_DOWN && ifi->racnt == 0) break; } if (ifi == NULL) break; } error = kevent(kq, NULL, 0, &events[0], 1, timeout); if (error < 1) { if (error < 0 && errno != EINTR) warnmsg(LOG_ERR, __func__, "kevent(): %s", strerror(errno)); continue; } if (events[0].ident == (uintptr_t)rtsock) rtsock_input(rtsock); else rtsol_input(rcvsock); } return (0); } static int init_capabilities(void) { #ifdef WITH_CASPER const char *const scripts[] = { resolvconf_script, managedconf_script, otherconf_script }; - const char *scripts_set[nitems(scripts)]; cap_channel_t *capcasper; nvlist_t *limits; - int count; capcasper = cap_init(); if (capcasper == NULL) return (-1); capllflags = cap_service_open(capcasper, "rtsold.llflags"); if (capllflags == NULL) return (-1); capscript = cap_service_open(capcasper, "rtsold.script"); if (capscript == NULL) return (-1); - count = 0; + limits = nvlist_create(0); for (size_t i = 0; i < nitems(scripts); i++) if (scripts[i] != NULL) - scripts_set[count++] = scripts[i]; - limits = nvlist_create(0); - nvlist_add_string_array(limits, "scripts", scripts_set, count); + nvlist_append_string_array(limits, "scripts", + scripts[i]); if (cap_limit_set(capscript, limits) != 0) return (-1); capsendmsg = cap_service_open(capcasper, "rtsold.sendmsg"); if (capsendmsg == NULL) return (-1); if (!fflag) { capsyslog = cap_service_open(capcasper, "system.syslog"); if (capsyslog == NULL) return (-1); } cap_close(capcasper); #endif /* WITH_CASPER */ return (0); } static int ifconfig(char *ifname) { struct ifinfo *ifi; struct sockaddr_dl *sdl; int flags; ifi = NULL; if ((sdl = if_nametosdl(ifname)) == NULL) { warnmsg(LOG_ERR, __func__, "failed to get link layer information for %s", ifname); goto bad; } if (find_ifinfo(sdl->sdl_index)) { warnmsg(LOG_ERR, __func__, "interface %s was already configured", ifname); goto bad; } if (Fflag) { struct in6_ndireq nd; int s; if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { warnmsg(LOG_ERR, __func__, "socket() failed."); goto bad; } memset(&nd, 0, sizeof(nd)); strlcpy(nd.ifname, ifname, sizeof(nd.ifname)); if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) { warnmsg(LOG_ERR, __func__, "cannot get accept_rtadv flag"); (void)close(s); goto bad; } nd.ndi.flags |= ND6_IFF_ACCEPT_RTADV; if (ioctl(s, SIOCSIFINFO_IN6, (caddr_t)&nd) < 0) { warnmsg(LOG_ERR, __func__, "cannot set accept_rtadv flag"); (void)close(s); goto bad; } (void)close(s); } if ((ifi = malloc(sizeof(*ifi))) == NULL) { warnmsg(LOG_ERR, __func__, "memory allocation failed"); goto bad; } memset(ifi, 0, sizeof(*ifi)); ifi->sdl = sdl; ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO; ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO; TAILQ_INIT(&ifi->ifi_rainfo); strlcpy(ifi->ifname, ifname, sizeof(ifi->ifname)); /* construct a router solicitation message */ if (make_packet(ifi)) goto bad; /* set link ID of this interface. */ #ifdef HAVE_SCOPELIB if (inet_zoneid(AF_INET6, 2, ifname, &ifi->linkid)) goto bad; #else /* XXX: assume interface IDs as link IDs */ ifi->linkid = ifi->sdl->sdl_index; #endif /* * check if the interface is available. * also check if SIOCGIFMEDIA ioctl is OK on the interface. */ ifi->mediareqok = 1; ifi->active = interface_status(ifi); if (!ifi->mediareqok) { /* * probe routers periodically even if the link status * does not change. */ ifi->probeinterval = PROBE_INTERVAL; } /* activate interface: interface_up returns 0 on success */ flags = interface_up(ifi->ifname); if (flags == 0) ifi->state = IFS_DELAY; else if (flags == IFS_TENTATIVE) ifi->state = IFS_TENTATIVE; else ifi->state = IFS_DOWN; rtsol_timer_update(ifi); TAILQ_INSERT_TAIL(&ifinfo_head, ifi, ifi_next); return (0); bad: free(sdl); free(ifi); return (-1); } struct rainfo * find_rainfo(struct ifinfo *ifi, struct sockaddr_in6 *sin6) { struct rainfo *rai; TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) if (memcmp(&rai->rai_saddr.sin6_addr, &sin6->sin6_addr, sizeof(rai->rai_saddr.sin6_addr)) == 0) return (rai); return (NULL); } struct ifinfo * find_ifinfo(int ifindex) { struct ifinfo *ifi; TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) { if (ifi->sdl->sdl_index == ifindex) return (ifi); } return (NULL); } static int make_packet(struct ifinfo *ifi) { size_t packlen = sizeof(struct nd_router_solicit), lladdroptlen = 0; struct nd_router_solicit *rs; char *buf; if ((lladdroptlen = lladdropt_length(ifi->sdl)) == 0) { warnmsg(LOG_INFO, __func__, "link-layer address option has null length" " on %s. Treat as not included.", ifi->ifname); } packlen += lladdroptlen; ifi->rs_datalen = packlen; /* allocate buffer */ if ((buf = malloc(packlen)) == NULL) { warnmsg(LOG_ERR, __func__, "memory allocation failed for %s", ifi->ifname); return (-1); } ifi->rs_data = buf; /* fill in the message */ rs = (struct nd_router_solicit *)buf; rs->nd_rs_type = ND_ROUTER_SOLICIT; rs->nd_rs_code = 0; rs->nd_rs_cksum = 0; rs->nd_rs_reserved = 0; buf += sizeof(*rs); /* fill in source link-layer address option */ if (lladdroptlen) lladdropt_fill(ifi->sdl, (struct nd_opt_hdr *)buf); return (0); } static struct timespec * rtsol_check_timer(void) { static struct timespec returnval; struct timespec now, rtsol_timer; struct ifinfo *ifi; struct rainfo *rai; struct ra_opt *rao, *raotmp; int error, flags; clock_gettime(CLOCK_MONOTONIC_FAST, &now); rtsol_timer = tm_max; TAILQ_FOREACH(ifi, &ifinfo_head, ifi_next) { if (TS_CMP(&ifi->expire, &now, <=)) { warnmsg(LOG_DEBUG, __func__, "timer expiration on %s, " "state = %d", ifi->ifname, ifi->state); while((rai = TAILQ_FIRST(&ifi->ifi_rainfo)) != NULL) { /* Remove all RA options. */ TAILQ_REMOVE(&ifi->ifi_rainfo, rai, rai_next); while ((rao = TAILQ_FIRST(&rai->rai_ra_opt)) != NULL) { TAILQ_REMOVE(&rai->rai_ra_opt, rao, rao_next); if (rao->rao_msg != NULL) free(rao->rao_msg); free(rao); } free(rai); } switch (ifi->state) { case IFS_DOWN: case IFS_TENTATIVE: /* interface_up returns 0 on success */ flags = interface_up(ifi->ifname); if (flags == 0) ifi->state = IFS_DELAY; else if (flags == IFS_TENTATIVE) ifi->state = IFS_TENTATIVE; else ifi->state = IFS_DOWN; break; case IFS_IDLE: { int oldstatus = ifi->active; int probe = 0; ifi->active = interface_status(ifi); if (oldstatus != ifi->active) { warnmsg(LOG_DEBUG, __func__, "%s status is changed" " from %d to %d", ifi->ifname, oldstatus, ifi->active); probe = 1; ifi->state = IFS_DELAY; } else if (ifi->probeinterval && (ifi->probetimer -= ifi->timer.tv_sec) <= 0) { /* probe timer expired */ ifi->probetimer = ifi->probeinterval; probe = 1; ifi->state = IFS_PROBE; } /* * If we need a probe, clear the previous * status wrt the "managed/other" configuration. */ if (probe) { ifi->managedconfig = 0; ifi->otherconfig = 0; } if (probe && mobile_node) { error = cap_probe_defrouters(capsendmsg, ifi); if (error != 0) warnmsg(LOG_DEBUG, __func__, "failed to probe routers: %d", error); } break; } case IFS_DELAY: ifi->state = IFS_PROBE; (void)cap_rssend(capsendmsg, ifi); break; case IFS_PROBE: if (ifi->probes < MAX_RTR_SOLICITATIONS) (void)cap_rssend(capsendmsg, ifi); else { warnmsg(LOG_INFO, __func__, "No answer after sending %d RSs", ifi->probes); ifi->probes = 0; ifi->state = IFS_IDLE; } break; } rtsol_timer_update(ifi); } else { /* Expiration check for RA options. */ int expire = 0; TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) { TAILQ_FOREACH_SAFE(rao, &rai->rai_ra_opt, rao_next, raotmp) { warnmsg(LOG_DEBUG, __func__, "RA expiration timer: " "type=%d, msg=%s, expire=%s", rao->rao_type, (char *)rao->rao_msg, sec2str(&rao->rao_expire)); if (TS_CMP(&now, &rao->rao_expire, >=)) { warnmsg(LOG_DEBUG, __func__, "RA expiration timer: " "expired."); TAILQ_REMOVE(&rai->rai_ra_opt, rao, rao_next); if (rao->rao_msg != NULL) free(rao->rao_msg); free(rao); expire = 1; } } } if (expire) ra_opt_handler(ifi); } if (TS_CMP(&ifi->expire, &rtsol_timer, <)) rtsol_timer = ifi->expire; } if (TS_CMP(&rtsol_timer, &tm_max, ==)) { warnmsg(LOG_DEBUG, __func__, "there is no timer"); return (NULL); } else if (TS_CMP(&rtsol_timer, &now, <)) /* this may occur when the interval is too small */ returnval.tv_sec = returnval.tv_nsec = 0; else TS_SUB(&rtsol_timer, &now, &returnval); now.tv_sec += returnval.tv_sec; now.tv_nsec += returnval.tv_nsec; warnmsg(LOG_DEBUG, __func__, "New timer is %s", sec2str(&now)); return (&returnval); } void rtsol_timer_update(struct ifinfo *ifi) { #define MILLION 1000000 #define DADRETRY 10 /* XXX: adhoc */ long interval; struct timespec now; bzero(&ifi->timer, sizeof(ifi->timer)); switch (ifi->state) { case IFS_DOWN: case IFS_TENTATIVE: if (++ifi->dadcount > DADRETRY) { ifi->dadcount = 0; ifi->timer.tv_sec = PROBE_INTERVAL; } else ifi->timer.tv_sec = 1; break; case IFS_IDLE: if (mobile_node) /* XXX should be configurable */ ifi->timer.tv_sec = 3; else ifi->timer = tm_max; /* stop timer(valid?) */ break; case IFS_DELAY: interval = arc4random_uniform(MAX_RTR_SOLICITATION_DELAY * MILLION); ifi->timer.tv_sec = interval / MILLION; ifi->timer.tv_nsec = (interval % MILLION) * 1000; break; case IFS_PROBE: if (ifi->probes < MAX_RTR_SOLICITATIONS) ifi->timer.tv_sec = RTR_SOLICITATION_INTERVAL; else /* * After sending MAX_RTR_SOLICITATIONS solicitations, * we're just waiting for possible replies; there * will be no more solicitation. Thus, we change * the timer value to MAX_RTR_SOLICITATION_DELAY based * on RFC 2461, Section 6.3.7. */ ifi->timer.tv_sec = MAX_RTR_SOLICITATION_DELAY; break; default: warnmsg(LOG_ERR, __func__, "illegal interface state(%d) on %s", ifi->state, ifi->ifname); return; } /* reset the timer */ if (TS_CMP(&ifi->timer, &tm_max, ==)) { ifi->expire = tm_max; warnmsg(LOG_DEBUG, __func__, "stop timer for %s", ifi->ifname); } else { clock_gettime(CLOCK_MONOTONIC_FAST, &now); TS_ADD(&now, &ifi->timer, &ifi->expire); now.tv_sec += ifi->timer.tv_sec; now.tv_nsec += ifi->timer.tv_nsec; warnmsg(LOG_DEBUG, __func__, "set timer for %s to %s", ifi->ifname, sec2str(&now)); } #undef MILLION } static void set_dumpfile(int sig __unused) { do_dump = 1; } static void set_exit(int sig __unused) { do_exit = 1; } static void usage(const char *progname) { if (strcmp(progname, "rtsold") == 0) { fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] " "[-p pidfile] [-R script-name] interface ...\n"); fprintf(stderr, "usage: rtsold [-dDfFm1] [-O script-name] " "[-p pidfile] [-R script-name] -a\n"); } else { fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] " "[-p pidfile] [-R script-name] interface ...\n"); fprintf(stderr, "usage: rtsol [-dDF] [-O script-name] " "[-p pidfile] [-R script-name] -a\n"); } exit(1); } void warnmsg(int priority, const char *func, const char *msg, ...) { va_list ap; char buf[BUFSIZ]; va_start(ap, msg); if (fflag) { if (priority <= log_upto) vwarnx(msg, ap); } else { snprintf(buf, sizeof(buf), "<%s> %s", func, msg); msg = buf; cap_vsyslog(capsyslog, priority, msg, ap); } va_end(ap); } /* * return a list of interfaces which is suitable to sending an RS. */ static char ** autoifprobe(void) { static char **argv = NULL; static int n = 0; char **a; int s = 0, i, found; struct ifaddrs *ifap, *ifa; struct in6_ndireq nd; /* initialize */ while (n--) free(argv[n]); if (argv) { free(argv); argv = NULL; } n = 0; if (getifaddrs(&ifap) != 0) return (NULL); if (!Fflag && (s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { warnmsg(LOG_ERR, __func__, "socket"); exit(1); } /* find an ethernet */ for (ifa = ifap; ifa; ifa = ifa->ifa_next) { if ((ifa->ifa_flags & IFF_UP) == 0) continue; if ((ifa->ifa_flags & IFF_POINTOPOINT) != 0) continue; if ((ifa->ifa_flags & IFF_LOOPBACK) != 0) continue; if ((ifa->ifa_flags & IFF_MULTICAST) == 0) continue; if (ifa->ifa_addr->sa_family != AF_INET6) continue; found = 0; for (i = 0; i < n; i++) { if (strcmp(argv[i], ifa->ifa_name) == 0) { found++; break; } } if (found) continue; /* * Skip the interfaces which IPv6 and/or accepting RA * is disabled. */ if (!Fflag) { memset(&nd, 0, sizeof(nd)); strlcpy(nd.ifname, ifa->ifa_name, sizeof(nd.ifname)); if (ioctl(s, SIOCGIFINFO_IN6, (caddr_t)&nd) < 0) { warnmsg(LOG_ERR, __func__, "ioctl(SIOCGIFINFO_IN6)"); exit(1); } if ((nd.ndi.flags & ND6_IFF_IFDISABLED)) continue; if (!(nd.ndi.flags & ND6_IFF_ACCEPT_RTADV)) continue; } /* if we find multiple candidates, just warn. */ if (n != 0 && dflag > 1) warnmsg(LOG_WARNING, __func__, "multiple interfaces found"); a = realloc(argv, (n + 1) * sizeof(char *)); if (a == NULL) { warnmsg(LOG_ERR, __func__, "realloc"); exit(1); } argv = a; argv[n] = strdup(ifa->ifa_name); if (!argv[n]) { warnmsg(LOG_ERR, __func__, "malloc"); exit(1); } n++; } if (n) { a = realloc(argv, (n + 1) * sizeof(char *)); if (a == NULL) { warnmsg(LOG_ERR, __func__, "realloc"); exit(1); } argv = a; argv[n] = NULL; if (dflag > 0) { for (i = 0; i < n; i++) warnmsg(LOG_WARNING, __func__, "probing %s", argv[i]); } } if (!Fflag) close(s); freeifaddrs(ifap); return (argv); }