Initial revision

svn path=/trunk/; revision=686

1 files changed, 191 insertions, 0 deletions

diff --git a/interface.c b/interface.c
new file mode 100644
index 00000000..9520f1c5
--- /dev/null
+++ b/interface.c
@@ -0,0 +1,191 @@
+/*
+ * interface.c -- implements fetchmail 'interface' and 'monitor' commands
+ *
+ * This module was implemented by George M. Sipe 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 <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <arpa/inet.h>
+#include <linux/netdevice.h>
+#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);
+	if (ioctl(socket_fd, SIOCGIFFLAGS, &request) < 0)
+		return(FALSE);
+	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) fprintf(stderr, "missing IP interface address\n");
+		exit(PS_SYNTAX);
+	}
+	*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) fprintf(stderr, "invalid IP interface address\n");
+		exit(PS_SYNTAX);
+	}
+	if (!inet_aton(cp2, &interface_mask)) {
+		(void) fprintf(stderr, "invalid IP interface mask\n");
+		exit(PS_SYNTAX);
+	}
+	/* 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)) {
+			fprintf(stderr, "fetchmail: skipping poll, %s down\n",
+				interface);
+			return(FALSE);
+		}
+		/* check the IP address (range) */
+		if ((ifinfo.addr.s_addr & interface_mask.s_addr) !=
+				interface_address.s_addr) {
+			fprintf(stderr,
+			   "fetchmail: skipping poll, %s IP address excluded\n",
+			   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) {
+		fprintf(stderr, "fetchmail: skipping poll, %s inactive\n",
+			monitor);
+		return(FALSE);
+	}
+
+	return(TRUE);
+}
+#endif	/* linux */