/* * interface.c -- implements fetchmail 'interface' and 'monitor' commands * * This module was implemented by George M. Sipe * or and is: * * Copyright (c) 1996 by George M. Sipe - ALL RIGHTS RESERVED * * This is free software; you can redistribute it and/or modify it under * the terms of the GNU General Public License as published by the Free * Software Foundation; version 2, or (at your option) any later version. */ #ifdef linux #include #include #include #include #include #include #include #include "fetchmail.h" static struct in_addr interface_address; static struct in_addr interface_mask; static int monitor_io = 0; typedef struct { struct in_addr addr, dstaddr, netmask; int rx_packets, tx_packets; } ifinfo_t; /* Get active network interface information. Return non-zero upon success. */ static int _get_ifinfo_(int socket_fd, FILE *stats_file, const char *ifname, ifinfo_t *ifinfo) { int namelen = strlen(ifname); struct ifreq request; char *cp, buffer[256]; /* initialize result */ memset((char *) ifinfo, 0, sizeof(ifinfo_t)); /* see if the interface is up */ strcpy(request.ifr_name, ifname); errno = 0; if (ioctl(socket_fd, SIOCGIFFLAGS, &request) < 0) error(PS_IOERR, errno, "interface status check failed"); if (!(request.ifr_flags & IFF_RUNNING)) return(FALSE); /* get the 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 IP address */ 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; /* 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; sscanf(cp, "%d %*d %*d %*d %*d %d %*d %*d %*d %*d %*d", &ifinfo->rx_packets, &ifinfo->tx_packets); 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 = -1; else result = _get_ifinfo_(socket_fd, stats_file, ifname, ifinfo); if (socket_fd >= 0) close(socket_fd); if (stats_file) fclose(stats_file); return(result); } /* Parse 'interface' specification. */ void interface_parse(void) { char *cp1, *cp2; /* in the event we point to a null string, make pointer null */ if (interface && !*interface) interface = NULL; if (monitor && !*monitor) monitor = NULL; /* if no interface specification present, all done */ if (!interface) return; /* find and isolate just the IP address */ if (!(cp1 = strchr(interface, '/'))) (void) error(PS_SYNTAX, 0, "missing IP interface address"); *cp1++ = '\000'; /* find and isolate just the netmask */ if (!(cp2 = strchr(cp1, '/'))) cp2 = "255.255.255.255"; else *cp2++ = '\000'; /* convert IP address and netmask */ if (!inet_aton(cp1, &interface_address)) (void) error(PS_SYNTAX, 0, "invalid IP interface address"); if (!inet_aton(cp2, &interface_mask)) (void) error(PS_SYNTAX, 0, "invalid IP interface mask"); /* apply the mask now to the IP address (range) required */ interface_address.s_addr &= interface_mask.s_addr; return; } /* Save interface I/O counts. */ void interface_note_activity(void) { ifinfo_t ifinfo; sleep(3); /* allow some time for the link to quiesce */ /* get the current I/O stats for the monitored link */ if (monitor && get_ifinfo(monitor, &ifinfo)) monitor_io = ifinfo.rx_packets + ifinfo.tx_packets; } /* Return TRUE if OK to poll, FALSE otherwise. */ int interface_approve(void) { ifinfo_t ifinfo; /* check interface IP address (range), if specified */ if (interface) { /* get interface info */ if (!get_ifinfo(interface, &ifinfo)) { (void) error(0, 0, "skipping poll, %s down", interface); return(FALSE); } /* check the IP address (range) */ if ((ifinfo.addr.s_addr & interface_mask.s_addr) != interface_address.s_addr) { (void) error(0, 0, "skipping poll, %s IP address excluded", interface); return(FALSE); } } /* if monitoring, check link for activity if it is up */ if (monitor && get_ifinfo(monitor, &ifinfo) && monitor_io == ifinfo.rx_packets + ifinfo.tx_packets) { (void) error(0, 0, "skipping poll, %s inactive", monitor); return(FALSE); } return(TRUE); } #endif /* linux */