e9b76e1f1
Denis Vlasenko
2008-05-22
Subject
dnsd: fixes various segfaults. One was a lib api change that was not updated and another is a stack buffer overflow. It also adds support for '*' in dnsd.conf. It resolves all hostnames to a specific ip address. This is useful if you for example want redirect all http traffic to your first-boot-web-
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libbb/udp_io.c+11 -6
| @@ -36,11 +36,12 @@ send_to_from(int fd, void *buf, size_t len, int flags, | |
| #else | |
| struct iovec iov[1]; | |
| struct msghdr msg; | |
| - | char cbuf[sizeof(struct in_pktinfo) |
| + | union { |
| + | char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))]; |
| #if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO) | |
| - | | sizeof(struct in6_pktinfo) /* (a|b) is poor man's max(a,b) */ |
| + | char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; |
| #endif | |
| - | ]; |
| + | } u; |
| struct cmsghdr* cmsgptr; | |
| if (from->sa_family != AF_INET | |
| @@ -57,15 +58,15 @@ send_to_from(int fd, void *buf, size_t len, int flags, | |
| iov[0].iov_base = buf; | |
| iov[0].iov_len = len; | |
| - | memset(cbuf, 0, sizeof(cbuf)); |
| + | memset(&u, 0, sizeof(u)); |
| memset(&msg, 0, sizeof(msg)); | |
| msg.msg_name = (void *)(struct sockaddr *)to; /* or compiler will annoy us */ | |
| msg.msg_namelen = tolen; | |
| msg.msg_iov = iov; | |
| msg.msg_iovlen = 1; | |
| - | msg.msg_control = cbuf; |
| - | msg.msg_controllen = sizeof(cbuf); |
| + | msg.msg_control = &u; |
| + | msg.msg_controllen = sizeof(u); |
| msg.msg_flags = flags; | |
| cmsgptr = CMSG_FIRSTHDR(&msg); | |
| @@ -89,6 +90,8 @@ send_to_from(int fd, void *buf, size_t len, int flags, | |
| pktptr->ipi6_addr = ((struct sockaddr_in6*)from)->sin6_addr; | |
| } | |
| #endif | |
| + | msg.msg_controllen = cmsgptr->cmsg_len; |
| + | |
| return sendmsg(fd, &msg, flags); | |
| #endif | |
| } | |
| @@ -109,7 +112,9 @@ recv_from_to(int fd, void *buf, size_t len, int flags, | |
| struct iovec iov[1]; | |
| union { | |
| char cmsg[CMSG_SPACE(sizeof(struct in_pktinfo))]; | |
| + | #if ENABLE_FEATURE_IPV6 && defined(IPV6_PKTINFO) |
| char cmsg6[CMSG_SPACE(sizeof(struct in6_pktinfo))]; | |
| + | #endif |
| } u; | |
| struct cmsghdr *cmsgptr; | |
| struct msghdr msg; | |
networking/dnsd.c+5 -3
| @@ -194,7 +194,8 @@ static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs) | |
| for (i = 1; i <= (int)(d->name[0]); i++) | |
| if (tolower(qs[i]) != d->name[i]) | |
| break; | |
| - | if (i > (int)(d->name[0])) { |
| + | if (i > (int)(d->name[0]) || |
| + | (d->name[0] == 1 && d->name[1] == '*')) { |
| strcpy((char *)as, d->ip); | |
| #if DEBUG | |
| fprintf(stderr, " OK as:%s\n", as); | |
| @@ -202,7 +203,8 @@ static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs) | |
| return 0; | |
| } | |
| } else if (type == REQ_PTR) { /* search by IP-address */ | |
| - | if (!strncmp((char*)&d->rip[1], (char*)&qs[1], strlen(d->rip)-1)) { |
| + | if ((d->name[0] != 1 || d->name[1] != '*') && |
| + | !strncmp((char*)&d->rip[1], (char*)&qs[1], strlen(d->rip)-1)) { |
| strcpy((char *)as, d->name); | |
| return 0; | |
| } | |
| @@ -401,7 +403,7 @@ int dnsd_main(int argc ATTRIBUTE_UNUSED, char **argv) | |
| r = process_packet(buf); | |
| if (r <= 0) | |
| continue; | |
| - | send_to_from(udps, buf, r, 0, &to->u.sa, &from->u.sa, lsa->len); |
| + | send_to_from(udps, buf, r, 0, &from->u.sa, &to->u.sa, lsa->len); |
| } | |
| return 0; | |
| } | |