Author: Gleb Paharenko Description: Workaround to this Debian bug Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=420129 --- This patch header follows DEP-3: http://dep.debian.net/deps/dep3/ --- a/dsniff.c +++ b/dsniff.c @@ -70,6 +70,80 @@ { } + +static int get_all_ifaces(struct ifreq **, int *); +static unsigned int get_addr_from_ifreq(struct ifreq *); + +int all_local_ipaddrs_chksum_disable() +{ + struct ifreq *ifaces; + int ifaces_count; + int i, ind = 0; + struct nids_chksum_ctl *ctlp; + unsigned int tmp; + + if (!get_all_ifaces(&ifaces, &ifaces_count)) + return -1; + ctlp = + (struct nids_chksum_ctl *) malloc(ifaces_count * + sizeof(struct + nids_chksum_ctl)); + if (!ctlp) + return -1; + for (i = 0; i < ifaces_count; i++) { + tmp = get_addr_from_ifreq(ifaces + i); + if (tmp) { + ctlp[ind].netaddr = tmp; + ctlp[ind].mask = inet_addr("255.255.255.255"); + ctlp[ind].action = NIDS_DONT_CHKSUM; + ind++; + } + } + free(ifaces); + nids_register_chksum_ctl(ctlp, ind); +} + +/* helper functions for Example 2 */ +unsigned int get_addr_from_ifreq(struct ifreq *iface) +{ + if (iface->ifr_addr.sa_family == AF_INET) + return ((struct sockaddr_in *) &(iface->ifr_addr))-> + sin_addr.s_addr; + return 0; +} + +static int get_all_ifaces(struct ifreq **ifaces, int *count) +{ + int ifaces_size = 8 * sizeof(struct ifreq); + struct ifconf param; + int sock; + unsigned int i; + + *ifaces = malloc(ifaces_size); + sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP); + if (sock <= 0) + return 0; + for (;;) { + param.ifc_len = ifaces_size; + param.ifc_req = *ifaces; + if (ioctl(sock, SIOCGIFCONF, ¶m)) + goto err; + if (param.ifc_len < ifaces_size) + break; + free(*ifaces); + ifaces_size *= 2; + ifaces = malloc(ifaces_size); + } + *count = param.ifc_len / sizeof(struct ifreq); + close(sock); + return 1; + err: + close(sock); + return 0; +} + + + int main(int argc, char *argv[]) { @@ -189,6 +263,8 @@ warnx("using %s", nids_params.filename); } } + + all_local_ipaddrs_chksum_disable(); nids_run();