diff options
Diffstat (limited to 'tcpip/rip98r.c')
| -rw-r--r-- | tcpip/rip98r.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/tcpip/rip98r.c b/tcpip/rip98r.c new file mode 100644 index 0000000..765e786 --- /dev/null +++ b/tcpip/rip98r.c @@ -0,0 +1,255 @@ +#include <unistd.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <syslog.h> + +#include <sys/types.h> +#include <sys/ioctl.h> + +#include <sys/socket.h> +#include <arpa/inet.h> +#include <net/if.h> +#include <netinet/in.h> +#include <net/route.h> + + +#include "rip98d.h" + +#define UNMATCH_ROUTE 0 +#define NO_ROUTE 1 +#define REPLACE_ROUTE 2 +#define ADDITIONAL_ROUTE 3 + +static int cmp_route(struct route_struct *route, struct in_addr addr, int bits, int metric) +{ + unsigned long int old_mask, new_mask; + unsigned long int old_addr, new_addr; + + old_mask = ntohl(bits2mask(route->bits)); + new_mask = ntohl(bits2mask(bits)); + + old_addr = route->addr.s_addr; + new_addr = addr.s_addr; + + if (bits < route->bits) { + new_addr = ntohl(new_addr) & new_mask; + old_addr = ntohl(old_addr) & new_mask; + } else { + new_addr = ntohl(new_addr) & old_mask; + old_addr = ntohl(old_addr) & old_mask; + } + + if (route->action == DEL_ROUTE || route->action == NEW_ROUTE) + return UNMATCH_ROUTE; + + if (old_addr != new_addr) + return UNMATCH_ROUTE; + + if (route->metric <= metric) + return NO_ROUTE; + + if (debug && logging) { + syslog(LOG_DEBUG, "comparing old: %s/%d to\n", inet_ntoa(route->addr), route->bits); + syslog(LOG_DEBUG, " new: %s/%d\n", inet_ntoa(addr), bits); + } + + if (route->bits <= bits) { + if (route->action == ORIG_ROUTE) { + if (debug && logging) + syslog(LOG_DEBUG, " better route, replacing existing route\n"); + return REPLACE_ROUTE; + } else { + if (debug && logging) + syslog(LOG_DEBUG, " better route, adding additional route\n"); + return ADDITIONAL_ROUTE; + } + } else { + if (debug && logging) + syslog(LOG_DEBUG, " better route, adding additional route\n"); + return ADDITIONAL_ROUTE; + } +} + +void receive_routes(int s) +{ + unsigned char message[500], *p; + struct sockaddr_in rem_addr; + struct in_addr addr; + struct route_struct *route, *new; + struct sockaddr_in trg; + struct rtentry rt; + unsigned long int netmask; + unsigned long int network; + int bits, metric; + int size, found, matched; + int mess_len; + int i; + + size = sizeof(struct sockaddr_in); + + mess_len = recvfrom(s, message, 500, 0, (struct sockaddr *)&rem_addr, &size); + + if (message[0] != RIPCMD_RESPONSE || message[1] != RIP_VERSION_98) { + if (debug && logging) { + syslog(LOG_DEBUG, "invalid RIP98 header received\n"); + syslog(LOG_DEBUG, " cmd: %d vers: %d\n", message[0], message[1]); + } + return; + } + + for (found = FALSE, i = 0; i < dest_count; i++) { + if (rem_addr.sin_addr.s_addr == dest_list[i].dest_addr.s_addr) { + found = TRUE; + break; + } + } + + if (!found) { + if (debug && logging) + syslog(LOG_DEBUG, "RIP98 message from unknown address %s\n", inet_ntoa(rem_addr.sin_addr)); + return; + } + + if (debug && logging) + syslog(LOG_DEBUG, "RIP98 message received from %s\n", inet_ntoa(rem_addr.sin_addr)); + + for (p = message + RIP98_HEADER; p < message + mess_len; p += RIP98_ENTRY) { + bcopy((char *)p, (char *)&addr, sizeof(addr)); + bits = p[4]; + metric = p[5]; + + network = inet_netof(addr); + + if (network == 0 || network == 127) { + if (debug && logging) + syslog(LOG_DEBUG, " route to %s/%d metric %d - rejected\n", inet_ntoa(addr), bits, metric); + continue; + } + + if (restrict) { + if (network != 44) { + if (debug && logging) + syslog(LOG_DEBUG, " route to %s/%d metric %d - rejected\n", inet_ntoa(addr), bits, metric); + continue; + } + } + + if (debug && logging) + syslog(LOG_DEBUG, " route to %s/%d metric %d\n", inet_ntoa(addr), bits, metric); + + metric++; + + if (metric > RIP98_INFINITY) + metric = RIP98_INFINITY; + + found = FALSE; + matched = FALSE; + + for (route = first_route; route != NULL; route = route->next) { + + switch (cmp_route(route, addr, bits, metric)) { + + case NO_ROUTE: + matched = TRUE; + break; + + case REPLACE_ROUTE: + route->action = DEL_ROUTE; + + case ADDITIONAL_ROUTE: + if (!found) { + if ((new = malloc(sizeof(struct route_struct))) == NULL) { + if (logging) + syslog(LOG_ERR, "out of memory\n"); + return; + } + + new->addr = addr; + new->bits = bits; + new->metric = metric; + new->action = NEW_ROUTE; + + new->next = first_route; + first_route = new; + + found = TRUE; + } + + matched = TRUE; + break; + + default: + break; + } + } + + if (!matched) { + if ((new = malloc(sizeof(struct route_struct))) == NULL) { + if (logging) + syslog(LOG_ERR, "out of memory\n"); + return; + } + + new->addr = addr; + new->bits = bits; + new->metric = metric; + new->action = NEW_ROUTE; + + new->next = first_route; + first_route = new; + } + } + + for (route = first_route; route != NULL; route = route->next) { + if (route->action == DEL_ROUTE) { + bzero((char *)&rt, sizeof(rt)); + + trg.sin_family = AF_INET; + trg.sin_addr = route->addr; + trg.sin_port = 0; + bcopy((char *)&trg, (char *)&rt.rt_dst, sizeof(struct sockaddr)); + + if (ioctl(s, SIOCDELRT, &rt) < 0) { + if (logging) + syslog(LOG_ERR, "SIOCDELRT: %m"); + } + } + } + + for (route = first_route; route != NULL; route = route->next) { + if (route->action == NEW_ROUTE) { + bzero((char *)&rt, sizeof(rt)); + + trg.sin_family = AF_INET; + trg.sin_addr = route->addr; + trg.sin_port = 0; + bcopy((char *)&trg, (char *)&rt.rt_dst, sizeof(struct sockaddr)); + + rt.rt_flags = RTF_UP | RTF_GATEWAY | RTF_DYNAMIC; + + if (route->bits == 32) { + rt.rt_flags |= RTF_HOST; + } else { + netmask = bits2mask(route->bits); + + trg.sin_family = AF_INET; + bcopy((char *)&netmask, (char *)&trg.sin_addr, sizeof(struct in_addr)); + trg.sin_port = 0; + bcopy((char *)&trg, (char *)&rt.rt_genmask, sizeof(struct sockaddr)); + } + + rt.rt_metric = route->metric; + + trg.sin_family = AF_INET; + trg.sin_addr = rem_addr.sin_addr; + trg.sin_port = 0; + bcopy((char *)&trg, (char *)&rt.rt_gateway, sizeof(struct sockaddr)); + + if (ioctl(s, SIOCADDRT, &rt) < 0) { + if (logging) + syslog(LOG_ERR, "SIOCADDRT: %m"); + } + } + } +} |