Reworked fix for #21

This commit is contained in:
Erik Ekman 2008-08-05 14:47:51 +00:00
parent 4d79bf6368
commit 7b90054346
2 changed files with 20 additions and 14 deletions

View File

@ -66,6 +66,15 @@ sigint(int sig)
running = 0; running = 0;
} }
static int
ip_cmp(int userid, struct query *q)
{
struct sockaddr_in *tempin;
tempin = (struct sockaddr_in *) &(q->from);
return memcmp(&(users[userid].host), &(tempin->sin_addr), sizeof(struct in_addr));
}
static int static int
tunnel_tun(int tun_fd, int dns_fd) tunnel_tun(int tun_fd, int dns_fd)
{ {
@ -167,10 +176,14 @@ tunnel_dns(int tun_fd, int dns_fd)
if (version == VERSION) { if (version == VERSION) {
userid = find_available_user(); userid = find_available_user();
if (userid >= 0) { if (userid >= 0) {
struct sockaddr_in *tempin;
users[userid].seed = rand(); users[userid].seed = rand();
memcpy(&(users[userid].host), &(dummy.q.from), dummy.q.fromlen); /* Store remote IP number */
tempin = (struct sockaddr_in *) &(dummy.q.from);
memcpy(&(users[userid].host), &(tempin->sin_addr), sizeof(struct in_addr));
memcpy(&(users[userid].q), &(dummy.q), sizeof(struct query)); memcpy(&(users[userid].q), &(dummy.q), sizeof(struct query));
users[userid].addrlen = dummy.q.fromlen;
users[userid].encoder = get_base32_encoder(); users[userid].encoder = get_base32_encoder();
send_version_response(dns_fd, VERSION_ACK, users[userid].seed, &users[userid]); send_version_response(dns_fd, VERSION_ACK, users[userid].seed, &users[userid]);
users[userid].q.id = 0; users[userid].q.id = 0;
@ -192,8 +205,7 @@ tunnel_dns(int tun_fd, int dns_fd)
users[userid].last_pkt = time(NULL); users[userid].last_pkt = time(NULL);
login_calculate(logindata, 16, password, users[userid].seed); login_calculate(logindata, 16, password, users[userid].seed);
if (check_ip && (dummy.q.fromlen != users[userid].addrlen || if (check_ip && ip_cmp(userid, &(dummy.q)) != 0) {
memcmp(&(users[userid].host), &(dummy.q.from), dummy.q.fromlen) != 0)) {
write_dns(dns_fd, &(dummy.q), "BADIP", 5); write_dns(dns_fd, &(dummy.q), "BADIP", 5);
} else { } else {
if (read >= 18 && (memcmp(logindata, unpacked+1, 16) == 0)) { if (read >= 18 && (memcmp(logindata, unpacked+1, 16) == 0)) {
@ -220,7 +232,7 @@ tunnel_dns(int tun_fd, int dns_fd)
read = unpack_data(unpacked, sizeof(unpacked), &(in[1]), read - 1, b32); read = unpack_data(unpacked, sizeof(unpacked), &(in[1]), read - 1, b32);
/* Ping packet, store userid */ /* Ping packet, store userid */
userid = unpacked[0]; userid = unpacked[0];
if (userid < 0 || userid >= USERS) { if (userid < 0 || userid >= USERS || ip_cmp(userid, &(dummy.q)) != 0) {
write_dns(dns_fd, &(dummy.q), "BADIP", 5); write_dns(dns_fd, &(dummy.q), "BADIP", 5);
return 0; /* illegal id */ return 0; /* illegal id */
} }
@ -249,8 +261,7 @@ tunnel_dns(int tun_fd, int dns_fd)
} }
/* Check sending ip number */ /* Check sending ip number */
if (check_ip && (dummy.q.fromlen != users[userid].addrlen || if (check_ip && ip_cmp(userid, &(dummy.q)) != 0) {
memcmp(&(users[userid].host), &(dummy.q.from), dummy.q.fromlen) != 0)) {
write_dns(dns_fd, &(dummy.q), "BADIP", 5); write_dns(dns_fd, &(dummy.q), "BADIP", 5);
} else { } else {
/* decode with this users encoding */ /* decode with this users encoding */
@ -259,7 +270,6 @@ tunnel_dns(int tun_fd, int dns_fd)
users[userid].last_pkt = time(NULL); users[userid].last_pkt = time(NULL);
memcpy(&(users[userid].q), &(dummy.q), sizeof(struct query)); memcpy(&(users[userid].q), &(dummy.q), sizeof(struct query));
users[userid].addrlen = dummy.q.fromlen;
memcpy(users[userid].inpacket.data + users[userid].inpacket.offset, unpacked, read); memcpy(users[userid].inpacket.data + users[userid].inpacket.offset, unpacked, read);
users[userid].inpacket.len += read; users[userid].inpacket.len += read;
users[userid].inpacket.offset += read; users[userid].inpacket.offset += read;
@ -288,10 +298,7 @@ tunnel_dns(int tun_fd, int dns_fd)
} }
} }
/* userid must be set for a reply to be sent */ /* userid must be set for a reply to be sent */
if (userid >= 0 && userid < USERS && dummy.q.fromlen == users[userid].addrlen && if (userid >= 0 && userid < USERS && ip_cmp(userid, &(dummy.q)) == 0 && users[userid].outpacket.len > 0) {
memcmp(&(users[userid].host), &(dummy.q.from), dummy.q.fromlen) == 0 &&
users[userid].outpacket.len > 0) {
write_dns(dns_fd, &(dummy.q), users[userid].outpacket.data, users[userid].outpacket.len); write_dns(dns_fd, &(dummy.q), users[userid].outpacket.data, users[userid].outpacket.len);
users[userid].outpacket.len = 0; users[userid].outpacket.len = 0;
users[userid].q.id = 0; users[userid].q.id = 0;

View File

@ -25,8 +25,7 @@ struct user {
time_t last_pkt; time_t last_pkt;
int seed; int seed;
in_addr_t tun_ip; in_addr_t tun_ip;
struct sockaddr host; struct in_addr host;
int addrlen;
struct query q; struct query q;
struct packet inpacket; struct packet inpacket;
struct packet outpacket; struct packet outpacket;