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synced 2025-12-26 09:29:01 +00:00
Refactor getsysroutes. It had two ways to get routes: by reading
/proc/net/route and with libdnet. I split those into two separate functions.
This commit is contained in:
david
275
tcpip.cc
275
tcpip.cc
@@ -3042,6 +3042,131 @@ static int nmaskcmp(const void *a, const void *b) {
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else return 1;
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}
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/* Read system routes from a handle to a /proc/net/route file. */
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static struct sys_route *getsysroutes_proc(FILE *routefp, int *howmany) {
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struct sys_route *routes = NULL;
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int route_capacity = 128;
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struct interface_info *ifaces;
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char buf[1024];
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char iface[16];
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char *p, *endptr;
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struct interface_info *ii;
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u32 mask;
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struct sockaddr_in *sin;
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int numifaces = 0, numroutes = 0;
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int i;
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ifaces = getinterfaces(&numifaces);
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routes = (struct sys_route *) safe_zalloc(route_capacity * sizeof(struct sys_route));
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(void) fgets(buf, sizeof(buf), routefp); /* Kill the first line (column headers) */
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while(fgets(buf,sizeof(buf), routefp)) {
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p = strtok(buf, " \t\n");
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if (!p) {
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error("Could not find interface in /proc/net/route line");
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continue;
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}
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if (*p == '*')
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continue; /* Deleted route -- any other valid reason for
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a route to start with an asterict? */
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Strncpy(iface, p, sizeof(iface));
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p = strtok(NULL, " \t\n");
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endptr = NULL;
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routes[numroutes].dest = strtoul(p, &endptr, 16);
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if (!endptr || *endptr) {
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error("Failed to determine Destination from /proc/net/route");
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continue;
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}
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/* Now for the gateway */
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p = strtok(NULL, " \t\n");
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if (!p) break;
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endptr = NULL;
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routes[numroutes].gw.s_addr = strtoul(p, &endptr, 16);
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if (!endptr || *endptr) {
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error("Failed to determine gw for %s from /proc/net/route", iface);
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}
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for(i=0; i < 5; i++) {
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p = strtok(NULL, " \t\n");
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if (!p) break;
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}
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if (!p) {
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error("Failed to find field %d in /proc/net/route", i + 2);
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continue;
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}
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endptr = NULL;
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routes[numroutes].netmask = strtoul(p, &endptr, 16);
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if (!endptr || *endptr) {
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error("Failed to determine mask from /proc/net/route");
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continue;
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}
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for(i=0; i < numifaces; i++) {
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if (!strcmp(iface, ifaces[i].devfullname)) {
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routes[numroutes].device = &ifaces[i];
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break;
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}
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}
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if (i == numifaces) {
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error("Failed to find device %s which was referenced in /proc/net/route", iface);
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continue;
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}
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/* Now to deal with some alias nonsense ... at least on Linux
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this file will just list the short name, even though IP
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information (such as source address) from an alias must be
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used. So if the purported device can't reach the gateway,
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try to find a device that starts with the same short
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devname, but can (e.g. eth0 -> eth0:3) */
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ii = &ifaces[i];
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mask = htonl((unsigned long) (0-1) << (32 - ii->netmask_bits));
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sin = (struct sockaddr_in *) &ii->addr;
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if (routes[numroutes].gw.s_addr && (sin->sin_addr.s_addr & mask) !=
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(routes[numroutes].gw.s_addr & mask)) {
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for(i=0; i < numifaces; i++) {
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if (ii == &ifaces[i]) continue;
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if (strcmp(ii->devname, ifaces[i].devname) == 0) {
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sin = (struct sockaddr_in *) &ifaces[i].addr;
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if ((sin->sin_addr.s_addr & mask) ==
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(routes[numroutes].gw.s_addr & mask)) {
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routes[numroutes].device = &ifaces[i];
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}
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}
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}
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}
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numroutes++;
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if (numroutes >= route_capacity) {
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route_capacity <<= 2;
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routes = (struct sys_route *) safe_realloc(routes, route_capacity * sizeof(struct sys_route));
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}
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}
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*howmany = numroutes;
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return routes;
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}
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/* Read system routes via libdnet. */
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static struct sys_route *getsysroutes_dnet(int *howmany) {
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struct dnet_collector_route_nfo dcrn;
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struct interface_info *ifaces;
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int numifaces = 0;
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ifaces = getinterfaces(&numifaces);
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dcrn.capacity = 128;
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dcrn.routes = (struct sys_route *) safe_zalloc(dcrn.capacity * sizeof(struct sys_route));
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dcrn.ifaces = ifaces;
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dcrn.numifaces = numifaces;
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dcrn.numroutes = 0;
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route_t *dr = route_open();
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if (!dr) fatal("%s: route_open() failed", __func__);
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if (route_loop(dr, collect_dnet_routes, &dcrn) != 0) {
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fatal("%s: route_loop() failed", __func__);
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}
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route_close(dr);
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*howmany = dcrn.numroutes;
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return dcrn.routes;
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}
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/* Parse the system routing table, converting each route into a
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sys_route entry. Returns an array of sys_routes. numroutes is set
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to the number of routes in the array. The routing table is only
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@@ -3049,141 +3174,39 @@ static int nmaskcmp(const void *a, const void *b) {
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The returned route array is sorted by netmask with the most
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specific matches first. */
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struct sys_route *getsysroutes(int *howmany) {
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int route_capacity = 128;
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static struct sys_route *routes = NULL;
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static int numroutes = 0;
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FILE *routefp;
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char buf[1024];
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char iface[16];
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char *p, *endptr;
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struct interface_info *ifaces;
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int numifaces = 0;
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int i;
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u32 mask;
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struct sockaddr_in *sin;
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struct interface_info *ii;
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if (!howmany) fatal("NULL howmany ptr passed to %s()", __func__);
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if (!routes) {
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routes = (struct sys_route *) safe_zalloc(route_capacity * sizeof(struct sys_route));
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ifaces = getinterfaces(&numifaces);
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/* First let us try Linux-style /proc/net/route */
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routefp = fopen("/proc/net/route", "r");
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if (routefp) {
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(void) fgets(buf, sizeof(buf), routefp); /* Kill the first line (column headers) */
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while(fgets(buf,sizeof(buf), routefp)) {
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p = strtok(buf, " \t\n");
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if (!p) {
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error("Could not find interface in /proc/net/route line");
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continue;
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}
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if (*p == '*')
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continue; /* Deleted route -- any other valid reason for
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a route to start with an asterict? */
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Strncpy(iface, p, sizeof(iface));
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p = strtok(NULL, " \t\n");
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endptr = NULL;
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routes[numroutes].dest = strtoul(p, &endptr, 16);
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if (!endptr || *endptr) {
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error("Failed to determine Destination from /proc/net/route");
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continue;
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}
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/* Now for the gateway */
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p = strtok(NULL, " \t\n");
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if (!p) break;
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endptr = NULL;
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routes[numroutes].gw.s_addr = strtoul(p, &endptr, 16);
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if (!endptr || *endptr) {
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error("Failed to determine gw for %s from /proc/net/route", iface);
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}
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for(i=0; i < 5; i++) {
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p = strtok(NULL, " \t\n");
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if (!p) break;
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}
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if (!p) {
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error("Failed to find field %d in /proc/net/route", i + 2);
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continue;
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}
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endptr = NULL;
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routes[numroutes].netmask = strtoul(p, &endptr, 16);
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if (!endptr || *endptr) {
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error("Failed to determine mask from /proc/net/route");
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continue;
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}
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for(i=0; i < numifaces; i++) {
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if (!strcmp(iface, ifaces[i].devfullname)) {
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routes[numroutes].device = &ifaces[i];
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break;
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}
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}
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if (i == numifaces) {
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error("Failed to find device %s which was referenced in /proc/net/route", iface);
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continue;
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}
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/* Now to deal with some alias nonsense ... at least on Linux
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this file will just list the short name, even though IP
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information (such as source address) from an alias must be
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used. So if the purported device can't reach the gateway,
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try to find a device that starts with the same short
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devname, but can (e.g. eth0 -> eth0:3) */
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ii = &ifaces[i];
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mask = htonl((unsigned long) (0-1) << (32 - ii->netmask_bits));
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sin = (struct sockaddr_in *) &ii->addr;
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if (routes[numroutes].gw.s_addr && (sin->sin_addr.s_addr & mask) !=
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(routes[numroutes].gw.s_addr & mask)) {
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for(i=0; i < numifaces; i++) {
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if (ii == &ifaces[i]) continue;
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if (strcmp(ii->devname, ifaces[i].devname) == 0) {
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sin = (struct sockaddr_in *) &ifaces[i].addr;
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if ((sin->sin_addr.s_addr & mask) ==
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(routes[numroutes].gw.s_addr & mask)) {
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routes[numroutes].device = &ifaces[i];
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}
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}
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}
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}
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numroutes++;
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if (numroutes >= route_capacity) {
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route_capacity <<= 2;
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routes = (struct sys_route *) safe_realloc(routes, route_capacity * sizeof(struct sys_route));
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}
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}
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} else {
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struct dnet_collector_route_nfo dcrn;
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dcrn.routes = routes;
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dcrn.numroutes = numroutes;
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dcrn.capacity = route_capacity;
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dcrn.ifaces = ifaces;
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dcrn.numifaces = numifaces;
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route_t *dr = route_open();
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if (!dr) fatal("%s: route_open() failed", __func__);
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if (route_loop(dr, collect_dnet_routes, &dcrn) != 0) {
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fatal("%s: route_loop() failed", __func__);
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}
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route_close(dr);
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/* These values could have changed in the callback */
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route_capacity = dcrn.capacity;
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numroutes = dcrn.numroutes;
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routes = dcrn.routes;
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}
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/* Ensure that the route array is sorted by netmask */
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for(i=1; i < numroutes; i++) {
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if (ntohl(routes[i].netmask) > ntohl(routes[i-1].netmask))
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break;
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}
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if (i < numroutes) {
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/* they're not sorted ... better take care of that */
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qsort(routes, numroutes, sizeof(routes[0]), nmaskcmp);
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}
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if (routes != NULL) {
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/* We have it cached. */
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*howmany = numroutes;
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return routes;
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}
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/* First let us try Linux-style /proc/net/route */
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routefp = fopen("/proc/net/route", "r");
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if (routefp)
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routes = getsysroutes_proc(routefp, howmany);
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else
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routes = getsysroutes_dnet(howmany);
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numroutes = *howmany;
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/* Ensure that the route array is sorted by netmask */
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for(i=1; i < numroutes; i++) {
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if (ntohl(routes[i].netmask) > ntohl(routes[i-1].netmask))
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break;
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}
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if (i < numroutes) {
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/* they're not sorted ... better take care of that */
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qsort(routes, numroutes, sizeof(routes[0]), nmaskcmp);
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}
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*howmany = numroutes;
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return routes;
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}
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