From cf3ca7e5d0ea1044eeb8a5ee71a057f2189350e1 Mon Sep 17 00:00:00 2001 From: Erik Ekman Date: Sat, 18 Nov 2006 16:19:39 +0000 Subject: [PATCH] Check ip address of incoming packet --- src/iodined.c | 73 +++++++++++++++++++++++++++++++-------------------- 1 file changed, 44 insertions(+), 29 deletions(-) diff --git a/src/iodined.c b/src/iodined.c index 41ce399..70ad089 100644 --- a/src/iodined.c +++ b/src/iodined.c @@ -150,26 +150,32 @@ tunnel(int tun_fd, int dns_fd) dnsd_send(dns_fd, &q, out, 8); } } else if(in[0] == 'L' || in[0] == 'l') { - // Login phase, handle auth - login_calculate(logindata, 16, password, seed); - if (read >= 17 && (memcmp(logindata, in+1, 16) == 0)) { - // Login ok, send ip/mtu info - myip.s_addr = my_ip; - clientip.s_addr = my_ip + inet_addr("0.0.0.1"); - - tmp[0] = strdup(inet_ntoa(myip)); - tmp[1] = strdup(inet_ntoa(clientip)); - - read = snprintf(out, sizeof(out), "%s-%s-%d", - tmp[0], tmp[1], my_mtu); - - dnsd_send(dns_fd, &q, out, read); - q.id = 0; - - free(tmp[1]); - free(tmp[0]); + // Check sending ip number + if (q.fromlen != u.addrlen || + memcmp(&(u.host), &(q.from), q.fromlen) != 0) { + dnsd_send(dns_fd, &q, "BADIP", 5); } else { - dnsd_send(dns_fd, &q, "LNAK", 4); + // Login phase, handle auth + login_calculate(logindata, 16, password, seed); + if (read >= 17 && (memcmp(logindata, in+1, 16) == 0)) { + // Login ok, send ip/mtu info + myip.s_addr = my_ip; + clientip.s_addr = my_ip + inet_addr("0.0.0.1"); + + tmp[0] = strdup(inet_ntoa(myip)); + tmp[1] = strdup(inet_ntoa(clientip)); + + read = snprintf(out, sizeof(out), "%s-%s-%d", + tmp[0], tmp[1], my_mtu); + + dnsd_send(dns_fd, &q, out, read); + q.id = 0; + + free(tmp[1]); + free(tmp[0]); + } else { + dnsd_send(dns_fd, &q, "LNAK", 4); + } } } else if((in[0] >= '0' && in[0] <= '9') || (in[0] >= 'a' && in[0] <= 'f') @@ -180,21 +186,30 @@ tunnel(int tun_fd, int dns_fd) code = in[0] - 'a' + 10; if ((in[0] >= 'A' && in[0] <= 'F')) code = in[0] - 'A' + 10; + + // Check sending ip number + if (q.fromlen != u.addrlen || + memcmp(&(u.host), &(q.from), q.fromlen) != 0) { + dnsd_send(dns_fd, &q, "BADIP", 5); + } else { + memcpy(packetbuf.data + packetbuf.offset, in + 1, read - 1); + packetbuf.len += read - 1; + packetbuf.offset += read - 1; - memcpy(packetbuf.data + packetbuf.offset, in + 1, read - 1); - packetbuf.len += read - 1; - packetbuf.offset += read - 1; + if (code & 1) { + outlen = sizeof(out); + uncompress(out, &outlen, packetbuf.data, packetbuf.len); - if (code & 1) { - outlen = sizeof(out); - uncompress(out, &outlen, packetbuf.data, packetbuf.len); + write_tun(tun_fd, out, outlen); - write_tun(tun_fd, out, outlen); - - packetbuf.len = packetbuf.offset = 0; + packetbuf.len = packetbuf.offset = 0; + } } } - if (outpacket.len > 0) { + if (q.fromlen == u.addrlen && + memcmp(&(u.host), &(q.from), q.fromlen) == 0 && + outpacket.len > 0) { + dnsd_send(dns_fd, &q, outpacket.data, outpacket.len); outpacket.len = 0; q.id = 0;