/* * interface.c -- implements fetchmail 'interface' and 'monitor' commands * * This module was implemented by George M. Sipe * or and is: * * Copyright (c) 1996,1997 by George M. Sipe * * FreeBSD specific portions written by and Copyright (c) 1999 * Andy Doran . * * For license terms, see the file COPYING in this directory. */ #include "fetchmail.h" #ifdef CAN_MONITOR #include #include #if defined(linux) #include #endif #include #include #if defined(STDC_HEADERS) #include #endif #if defined(HAVE_UNISTD_H) #include #endif #include #include #include #include #include #if defined(__FreeBSD__) #if defined __FreeBSD_USE_KVM #if __FreeBSD_version >= 300001 #include #endif #include #include #include #else #include #include #include #endif #endif #include "socket.h" #include "i18n.h" #include "tunable.h" typedef struct { struct in_addr addr, dstaddr, netmask; int rx_packets, tx_packets; } ifinfo_t; struct interface_pair_s { struct in_addr interface_address; struct in_addr interface_mask; } *interface_pair; /* * Count of packets to see on an interface before monitor considers it up. * Needed because when pppd shuts down the link, the packet counts go up * by two (one rx and one tx?, maybe). A value of 2 seems to do the trick, * but we'll give it some extra. */ #define MONITOR_SLOP 5 #ifdef linux #define have_interface_init static const char *netdevfmt; void interface_init(void) /* figure out which /proc/net/dev format to use */ { struct utsname utsname; /* Linux 2.2 -- transmit packet count in 10th field */ netdevfmt = "%d %d %*d %*d %*d %d %*d %*d %*d %d %*d %*d %d"; if (uname(&utsname) < 0) return; else { int major, minor; if (sscanf(utsname.release, "%d.%d.%*d", &major, &minor) >= 2 && (major < 2 || (major == 2 && minor < 2))) /* pre-linux-2.2 format -- transmit packet count in 8th field */ netdevfmt = "%d %d %*d %*d %*d %d %*d %d %*d %*d %*d %*d %d"; } } static int _get_ifinfoGT_(int socket_fd, FILE *stats_file, const char *ifname, ifinfo_t *ifinfo) /* get active network interface information - return non-zero upon success */ { int namelen = strlen(ifname); struct ifreq request; char *cp, buffer[256]; int found = 0; int counts[4]; /* initialize result */ memset((char *) ifinfo, 0, sizeof(ifinfo_t)); /* get the packet I/O counts */ while (fgets(buffer, sizeof(buffer) - 1, stats_file)) { for (cp = buffer; *cp && *cp == ' '; ++cp); if (!strncmp(cp, ifname, namelen) && cp[namelen] == ':') { cp += namelen + 1; if (sscanf(cp, netdevfmt, counts, counts+1, counts+2, counts+3,&found)>4) { /* found = dummy */ /* newer kernel with byte counts */ ifinfo->rx_packets=counts[1]; ifinfo->tx_packets=counts[3]; } else { /* older kernel, no byte counts */ ifinfo->rx_packets=counts[0]; ifinfo->tx_packets=counts[2]; } found = 1; } } if (!found) return (FALSE); /* see if the interface is up */ strcpy(request.ifr_name, ifname); if (ioctl(socket_fd, SIOCGIFFLAGS, &request) < 0) return(FALSE); if (!(request.ifr_flags & IFF_RUNNING)) return(FALSE); /* get the (local) IP address */ strcpy(request.ifr_name, ifname); if (ioctl(socket_fd, SIOCGIFADDR, &request) < 0) return(FALSE); ifinfo->addr = ((struct sockaddr_in *) (&request.ifr_addr))->sin_addr; /* get the PPP destination (remote) IP address */ ifinfo->dstaddr.s_addr = 0; strcpy(request.ifr_name, ifname); if (ioctl(socket_fd, SIOCGIFDSTADDR, &request) >= 0) ifinfo->dstaddr = ((struct sockaddr_in *) (&request.ifr_dstaddr))->sin_addr; /* get the netmask */ strcpy(request.ifr_name, ifname); if (ioctl(socket_fd, SIOCGIFNETMASK, &request) >= 0) { ifinfo->netmask = ((struct sockaddr_in *) (&request.ifr_netmask))->sin_addr; return (TRUE); } return(FALSE); } static int get_ifinfo(const char *ifname, ifinfo_t *ifinfo) { int socket_fd = socket(AF_INET, SOCK_DGRAM, 0); FILE *stats_file = fopen("/proc/net/dev", "r"); int result; if (socket_fd < 0 || !stats_file) result = FALSE; else { char *tmp = xstrdup(ifname); char *sp = strchr(tmp, '/'); /* hide slash and trailing info from ifname */ if (sp) *sp = '\0'; result = _get_ifinfoGT_(socket_fd, stats_file, ifname, ifinfo); free(tmp); } if (socket_fd >= 0) SockClose(socket_fd); if (stats_file) fclose(stats_file); /* not checking should be safe, mode was "r" */ return(result); } #elif defined __FreeBSD__ #if defined __FreeBSD_USE_KVM static kvm_t *kvmfd; static struct nlist symbols[] = { {"_ifnet"}, {NULL} }; static u_long ifnet_savedaddr; static gid_t if_rgid; static gid_t if_egid; void interface_set_gids(gid_t egid, gid_t rgid) { if_rgid = rgid; if_egid = egid; } static int openkvm(void) { if ((kvmfd = kvm_open(NULL, NULL, NULL, O_RDONLY, NULL)) == NULL) return FALSE; if (kvm_nlist(kvmfd, symbols) < 0) return FALSE; if (kvm_read(kvmfd, (unsigned long) symbols[0].n_value, &ifnet_savedaddr, sizeof(unsigned long)) == -1) return FALSE; return TRUE; } static int get_ifinfo(const char *ifname, ifinfo_t *ifinfo) { char tname[16]; char iname[16]; struct ifnet ifnet; unsigned long ifnet_addr = ifnet_savedaddr; #if __FreeBSD_version >= 300001 struct ifnethead ifnethead; struct ifaddrhead ifaddrhead; #endif struct ifaddr ifaddr; unsigned long ifaddr_addr; struct sockaddr sa; unsigned long sa_addr; uint i; if (if_egid) setegid(if_egid); for (i = 0; ifname[i] && ifname[i] != '/' && i < sizeof(iname) - 1; i++) iname[i] = ifname[i]; iname[i] = '\0'; if (!kvmfd) { if (!openkvm()) { report(stderr, 0, GT_("Unable to open kvm interface. Make sure fetchmail is SGID kmem.")); if (if_egid) setegid(if_rgid); exit(1); } } #if __FreeBSD_version >= 300001 kvm_read(kvmfd, ifnet_savedaddr, (char *) &ifnethead, sizeof ifnethead); ifnet_addr = (u_long) ifnethead.tqh_first; #else ifnet_addr = ifnet_savedaddr; #endif while (ifnet_addr) { kvm_read(kvmfd, ifnet_addr, &ifnet, sizeof(ifnet)); kvm_read(kvmfd, (unsigned long) ifnet.if_name, tname, sizeof tname); snprintf(tname + strlen(tname), sizeof(tname) - strlen(tname), "%d", ifnet.if_unit); if (!strcmp(tname, iname)) { if (!(ifnet.if_flags & IFF_UP)) { if (if_egid) setegid(if_rgid); return 0; } ifinfo->rx_packets = ifnet.if_ipackets; ifinfo->tx_packets = ifnet.if_opackets; #if __FreeBSD_version >= 300001 ifaddr_addr = (u_long) ifnet.if_addrhead.tqh_first; #else ifaddr_addr = (u_long) ifnet.if_addrlist; #endif while(ifaddr_addr) { kvm_read(kvmfd, ifaddr_addr, &ifaddr, sizeof(ifaddr)); kvm_read(kvmfd, (u_long)ifaddr.ifa_addr, &sa, sizeof(sa)); if (sa.sa_family != AF_INET) { #if __FreeBSD_version >= 300001 ifaddr_addr = (u_long) ifaddr.ifa_link.tqe_next; #else ifaddr_addr = (u_long) ifaddr.ifa_next; #endif continue; } ifinfo->addr.s_addr = *(u_long *)(sa.sa_data + 2); kvm_read(kvmfd, (u_long)ifaddr.ifa_dstaddr, &sa, sizeof(sa)); ifinfo->dstaddr.s_addr = *(u_long *)(sa.sa_data + 2); kvm_read(kvmfd, (u_long)ifaddr.ifa_netmask, &sa, sizeof(sa)); ifinfo->netmask.s_addr = *(u_long *)(sa.sa_data + 2); if (if_egid) setegid(if_rgid); return 1; } if (if_egid) setegid(if_rgid); return 0; } #if __FreeBSD_version >= 300001 ifnet_addr = (u_long) ifnet.if_link.tqe_next; #else ifnet_addr = (unsigned long) ifnet.if_next; #endif } if (if_egid) setegid(if_rgid); return 0; } #else /* Do not use KVM on FreeBSD */ /* * Expand the compacted form of addresses as returned via the * configuration read via sysctl(). */ static void rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo) { struct sockaddr *sa; int i; #define ROUNDUP(a) \ ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len)) memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info)); for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) { if ((rtinfo->rti_addrs & (1 << i)) == 0) continue; rtinfo->rti_info[i] = sa = (struct sockaddr *)cp; ADVANCE(cp, sa); } #undef ROUNDUP #undef ADVANCE } static int get_ifinfo(const char *ifname, ifinfo_t *ifinfo) { uint i; int rc = 0; int ifindex = -1; size_t needed; char *buf = NULL; char *lim = NULL; char *next = NULL; struct if_msghdr *ifm; struct ifa_msghdr *ifam; struct sockaddr_in *sin; struct sockaddr_dl *sdl; struct rt_addrinfo info; char iname[16]; int mib[6]; memset(ifinfo, 0, sizeof(ifinfo)); /* trim interface name */ for (i = 0; i < sizeof(iname) && ifname[i] && ifname[i] != '/'; i++) iname[i] = ifname[i]; if (i == 0 || i == sizeof(iname)) { report(stderr, GT_("Unable to parse interface name from %s"), ifname); return 0; } iname[i] = 0; /* get list of existing interfaces */ mib[0] = CTL_NET; mib[1] = PF_ROUTE; mib[2] = 0; mib[3] = AF_INET; /* Only IP addresses please. */ mib[4] = NET_RT_IFLIST; mib[5] = 0; /* List all interfaces. */ /* Get interface data. */ if (sysctl(mib, 6, NULL, &needed, NULL, 0) == -1) { report(stderr, GT_("get_ifinfo: sysctl (iflist estimate) failed")); exit(1); } if ((buf = (char *)malloc(needed)) == NULL) { report(stderr, GT_("get_ifinfo: malloc failed")); exit(1); } if (sysctl(mib, 6, buf, &needed, NULL, 0) == -1) { report(stderr, GT_("get_ifinfo: sysctl (iflist) failed")); exit(1); } lim = buf+needed; /* first look for the interface information */ next = buf; while (next < lim) { ifm = (struct if_msghdr *)next; next += ifm->ifm_msglen; if (ifm->ifm_version != RTM_VERSION) { report(stderr, GT_("Routing message version %d not understood."), ifm->ifm_version); exit(1); } if (ifm->ifm_type == RTM_IFINFO) { sdl = (struct sockaddr_dl *)(ifm + 1); if (!(strlen(iname) == sdl->sdl_nlen && strncmp(iname, sdl->sdl_data, sdl->sdl_nlen) == 0)) { continue; } if ( !(ifm->ifm_flags & IFF_UP) ) { /* the interface is down */ goto get_ifinfo_end; } ifindex = ifm->ifm_index; ifinfo->rx_packets = ifm->ifm_data.ifi_ipackets; ifinfo->tx_packets = ifm->ifm_data.ifi_opackets; break; } } if (ifindex < 0) { /* we did not find an interface with a matching name */ report(stderr, GT_("No interface found with name %s"), iname); goto get_ifinfo_end; } /* now look for the interface's IP address */ next = buf; while (next < lim) { ifam = (struct ifa_msghdr *)next; next += ifam->ifam_msglen; if (ifindex > 0 && ifam->ifam_type == RTM_NEWADDR && ifam->ifam_index == ifindex) { /* Expand the compacted addresses */ info.rti_addrs = ifam->ifam_addrs; rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam, &info); /* Check for IPv4 address information only */ if (info.rti_info[RTAX_IFA]->sa_family != AF_INET) { continue; } rc = 1; sin = (struct sockaddr_in *)info.rti_info[RTAX_IFA]; if (sin) { ifinfo->addr = sin->sin_addr; } sin = (struct sockaddr_in *)info.rti_info[RTAX_NETMASK]; if (!sin) { ifinfo->netmask = sin->sin_addr; } /* note: RTAX_BRD contains the address at the other * end of a point-to-point link or the broadcast address * of non point-to-point link */ sin = (struct sockaddr_in *)info.rti_info[RTAX_BRD]; if (!sin) { ifinfo->dstaddr = sin->sin_addr; } break; } } if (rc == 0) { report(stderr, GT_("No IP address found for %s"), iname); } get_ifinfo_end: free(buf); return rc; } #endif /* __FREEBSD_USE_SYSCTL_GET_IFFINFO */ #endif #ifndef HAVE_INET_ATON /* * Note: This is not a true replacement for inet_aton(), as it won't * do the right thing on "255.255.255.255" (which translates to -1 on * most machines). Fortunately this code will be used only if you're * on an older Linux that lacks a real implementation. */ #ifdef HAVE_NETINET_IN_SYSTM_H # include # include #endif #include #include #include #include static int inet_aton(const char *cp, struct in_addr *inp) { long addr; addr = inet_addr(cp); if (addr == ((long) -1)) return 0; memcpy(inp, &addr, sizeof(addr)); return 1; } #endif /* HAVE_INET_ATON */ void interface_parse(char *buf, struct hostdata *hp) /* parse 'interface' specification */ { char *cp1, *cp2; char mask1[] = "255.255.255.255"; hp->interface = xstrdup(buf); /* find and isolate just the IP address */ if (!(cp1 = strchr(buf, '/'))) { (void) report(stderr, GT_("missing IP interface address\n")); exit(PS_SYNTAX); } *cp1++ = '\000'; /* find and isolate just the netmask */ if (!(cp2 = strchr(cp1, '/'))) cp2 = mask1; else *cp2++ = '\000'; /* convert IP address and netmask */ hp->interface_pair = (struct interface_pair_s *)xmalloc(sizeof(struct interface_pair_s)); if (!inet_aton(cp1, &hp->interface_pair->interface_address)) { (void) report(stderr, GT_("invalid IP interface address\n")); exit(PS_SYNTAX); } if (!inet_aton(cp2, &hp->interface_pair->interface_mask)) { (void) report(stderr, GT_("invalid IP interface mask\n")); exit(PS_SYNTAX); } /* apply the mask now to the IP address (range) required */ hp->interface_pair->interface_address.s_addr &= hp->interface_pair->interface_mask.s_addr; /* restore original interface string (for configuration dumper) */ *--cp1 = '/'; return; } void interface_note_activity(struct hostdata *hp) /* save interface I/O counts */ { ifinfo_t ifinfo; struct query *ctl; /* if not monitoring link, all done */ if (!hp->monitor) return; /* get the current I/O stats for the monitored link */ if (get_ifinfo(hp->monitor, &ifinfo)) /* update this and preceeding host entries using the link (they were already set during this pass but the I/O count has now changed and they need to be re-updated) */ for (ctl = querylist; ctl; ctl = ctl->next) { if (ctl->server.monitor && !strcmp(hp->monitor, ctl->server.monitor)) ctl->server.monitor_io = ifinfo.rx_packets + ifinfo.tx_packets; /* do NOT update host entries following this one */ if (&ctl->server == hp) break; } #ifdef ACTIVITY_DEBUG (void) report(stdout, GT_("activity on %s -noted- as %d\n"), hp->monitor, hp->monitor_io); #endif } int interface_approve(struct hostdata *hp, flag domonitor) /* return TRUE if OK to poll, FALSE otherwise */ { ifinfo_t ifinfo; /* check interface IP address (range), if specified */ if (hp->interface) { /* get interface info */ if (!get_ifinfo(hp->interface, &ifinfo)) { (void) report(stdout, GT_("skipping poll of %s, %s down\n"), hp->pollname, hp->interface); return(FALSE); } /* check the IP addresses (range) */ if (!( /* check remote IP address */ ((ifinfo.dstaddr.s_addr != 0) && (ifinfo.dstaddr.s_addr & hp->interface_pair->interface_mask.s_addr) == hp->interface_pair->interface_address.s_addr) || /* check local IP address */ ((ifinfo.addr.s_addr & hp->interface_pair->interface_mask.s_addr) == hp->interface_pair->interface_address.s_addr) ) ) { (void) report(stdout, GT_("skipping poll of %s, %s IP address excluded\n"), hp->pollname, hp->interface); return(FALSE); } } /* if not monitoring link, all done */ if (!domonitor || !hp->monitor) return(TRUE); #ifdef ACTIVITY_DEBUG (void) report(stdout, GT_("activity on %s checked as %d\n"), hp->monitor, hp->monitor_io); #endif /* if monitoring, check link for activity if it is up */ if (get_ifinfo(hp->monitor, &ifinfo)) { int diff = (ifinfo.rx_packets + ifinfo.tx_packets) - hp->monitor_io; /* * There are three cases here: * * (a) If the new packet count is less than the recorded one, * probably pppd was restarted while fetchmail was running. * Don't skip. * * (b) newpacket count is greater than the old packet count, * but the difference is small and may just reflect the overhead * of a link shutdown. Skip. * * (c) newpacket count is greater than the old packet count, * and the difference is large. Connection is live. Don't skip. */ if (diff >= 0 && diff <= MONITOR_SLOP) { (void) report(stdout, GT_("skipping poll of %s, %s inactive\n"), hp->pollname, hp->monitor); return(FALSE); } } #ifdef ACTIVITY_DEBUG report(stdout, GT_("activity on %s was %d, is %d\n"), hp->monitor, hp->monitor_io, ifinfo.rx_packets + ifinfo.tx_packets); #endif return(TRUE); } #endif /* CAN_MONITOR */ #ifndef have_interface_init void interface_init(void) {} #endif