dnsd: fix several buglets, make smaller
No binary (build failed)
—
(log yok)
| @@ -673,7 +673,7 @@ | |
| " -c Config filename\n" \ | |
| " -t TTL in seconds\n" \ | |
| " -p Listening port\n" \ | |
| - | " -i Listening iface ip (default all)\n" \ |
| + | " -i Listening ip (default all)\n" \ |
| " -d Daemonize" | |
| #define dos2unix_trivial_usage \ | |
| @@ -19,13 +19,6 @@ | |
| #include "busybox.h" | |
| - | static const char *fileconf = "/etc/dnsd.conf"; |
| - | #define LOCK_FILE "/var/run/dnsd.lock" |
| - | |
| - | // Must match getopt32 call |
| - | #define OPT_daemon (option_mask32 & 0x10) |
| - | #define OPT_verbose (option_mask32 & 0x20) |
| - | |
| //#define DEBUG 1 | |
| #define DEBUG 0 | |
| @@ -75,9 +68,16 @@ struct dns_entry { // element of known name, ip address and reversed ip address | |
| char name[MAX_HOST_LEN]; | |
| }; | |
| - | static struct dns_entry *dnsentry = NULL; |
| + | static struct dns_entry *dnsentry; |
| static uint32_t ttl = DEFAULT_TTL; | |
| + | static const char *fileconf = "/etc/dnsd.conf"; |
| + | |
| + | // Must match getopt32 call |
| + | #define OPT_daemon (option_mask32 & 0x10) |
| + | #define OPT_verbose (option_mask32 & 0x20) |
| + | |
| + | |
| /* | |
| * Convert host name from C-string to dns length/string. | |
| */ | |
| @@ -135,12 +135,12 @@ static int getfileentry(FILE * fp, struct dns_entry *s) | |
| while (*r != ' ' && *r != '\t') | |
| r++; | |
| *r++ = '\0'; | |
| - | if (sscanf(r, "%u.%u.%u.%u", &a, &b, &c, &d) != 4) { |
| + | if (sscanf(r, ".%u.%u.%u.%u"+1, &a, &b, &c, &d) != 4) { |
| free(line); | |
| goto restart; /* skipping wrong lines */ | |
| } | |
| - | sprintf(s->ip, "%u.%u.%u.%u", a, b, c, d); |
| + | sprintf(s->ip, ".%u.%u.%u.%u"+1, a, b, c, d); |
| sprintf(s->rip, ".%u.%u.%u.%u", d, c, b, a); | |
| undot((uint8_t*)s->rip); | |
| convname(s->name, (uint8_t*)name); | |
| @@ -185,7 +185,7 @@ static void dnsentryinit(void) | |
| static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs) | |
| { | |
| int i; | |
| - | struct dns_entry *d=dnsentry; |
| + | struct dns_entry *d = dnsentry; |
| do { | |
| #if DEBUG | |
| @@ -201,17 +201,13 @@ static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs) | |
| if (tolower(qs[i]) != d->name[i]) | |
| break; | |
| if (i > (int)(d->name[0])) { | |
| - | #if DEBUG |
| - | fprintf(stderr, " OK"); |
| - | #endif |
| strcpy((char *)as, d->ip); | |
| #if DEBUG | |
| - | fprintf(stderr, " as:%s\n", as); |
| + | fprintf(stderr, " OK as:%s\n", as); |
| #endif | |
| - | return 0; |
| + | return 0; |
| } | |
| - | } else |
| - | if (type == REQ_PTR) { /* search by IP-address */ |
| + | } else if (type == REQ_PTR) { /* search by IP-address */ |
| if (!strncmp((char*)&d->rip[1], (char*)&qs[1], strlen(d->rip)-1)) { | |
| strcpy((char *)as, d->name); | |
| return 0; | |
| @@ -226,7 +222,6 @@ static int table_lookup(uint16_t type, uint8_t * as, uint8_t * qs) | |
| /* | |
| * Decode message and generate answer | |
| */ | |
| - | #define eret(s) do { fputs(s, stderr); return -1; } while (0) |
| static int process_packet(uint8_t * buf) | |
| { | |
| struct dns_head *head; | |
| @@ -241,11 +236,15 @@ static int process_packet(uint8_t * buf) | |
| answstr[0] = '\0'; | |
| head = (struct dns_head *)buf; | |
| - | if (head->nquer == 0) |
| - | eret("no queries\n"); |
| + | if (head->nquer == 0) { |
| + | bb_error_msg("no queries"); |
| + | retunr -1; |
| + | } |
| - | if (head->flags & 0x8000) |
| - | eret("ignoring response packet\n"); |
| + | if (head->flags & 0x8000) { |
| + | bb_error_msg("ignoring response packet"); |
| + | retunr -1; |
| + | } |
| from = (void *)&head[1]; // start of query string | |
| next = answb = from + strlen((char *)from) + 1 + sizeof(struct dns_prop); // where to append answer block | |
| @@ -286,8 +285,7 @@ static int process_packet(uint8_t * buf) | |
| } | |
| memcpy(answstr, &a.s_addr, 4); // save before a disappears | |
| outr.rlen = 4; // uint32_t IP | |
| - | } |
| - | else |
| + | } else |
| outr.rlen = strlen((char *)answstr) + 1; // a host name | |
| outr.r = answstr; // 32 bit ip or a host name | |
| outr.flags |= 0x0400; /* authority-bit */ | |
| @@ -316,7 +314,7 @@ static int process_packet(uint8_t * buf) | |
| head->nauth = head->nadd = htons(0); | |
| head->nquer = htons(1); | |
| - | packet_len = next - (void *)buf; |
| + | packet_len = (uint8_t *)next - buf; |
| return packet_len; | |
| } | |
| @@ -325,7 +323,7 @@ static int process_packet(uint8_t * buf) | |
| */ | |
| static void interrupt(int x) | |
| { | |
| - | unlink(LOCK_FILE); |
| + | /* unlink("/var/run/dnsd.lock"); */ |
| bb_error_msg("interrupt, exiting\n"); | |
| exit(2); | |
| } | |
| @@ -333,7 +331,7 @@ static void interrupt(int x) | |
| int dnsd_main(int argc, char **argv); | |
| int dnsd_main(int argc, char **argv) | |
| { | |
| - | char *listen_interface = NULL; |
| + | const char *listen_interface = "0.0.0.0"; |
| char *sttl, *sport; | |
| len_and_sockaddr *lsa; | |
| int udps; | |
| @@ -346,7 +344,7 @@ int dnsd_main(int argc, char **argv) | |
| if (option_mask32 & 0x4) // -t | |
| ttl = xatou_range(sttl, 1, 0xffffffff); | |
| if (option_mask32 & 0x8) // -p | |
| - | port = xatou_range(sttl, 1, 0xffff); |
| + | port = xatou_range(sport, 1, 0xffff); |
| if (OPT_verbose) { | |
| bb_info_msg("listen_interface: %s", listen_interface); | |
| @@ -355,7 +353,6 @@ int dnsd_main(int argc, char **argv) | |
| } | |
| if (OPT_daemon) { | |
| - | //FIXME: NOMMU will NOT set LOGMODE_SYSLOG! |
| #ifdef BB_NOMMU | |
| if (!re_execed) | |
| vfork_daemon_rexec(1, 0, argv); | |
| @@ -368,7 +365,7 @@ int dnsd_main(int argc, char **argv) | |
| dnsentryinit(); | |
| signal(SIGINT, interrupt); | |
| - | signal(SIGPIPE, SIG_IGN); |
| + | /* why? signal(SIGPIPE, SIG_IGN); */ |
| signal(SIGHUP, SIG_IGN); | |
| #ifdef SIGTSTP | |
| signal(SIGTSTP, SIG_IGN); | |
| @@ -377,50 +374,31 @@ int dnsd_main(int argc, char **argv) | |
| signal(SIGURG, SIG_IGN); | |
| #endif | |
| - | lsa = xhost2sockaddr(listen_interface, port); |
| + | lsa = xdotted2sockaddr(listen_interface, port); |
| udps = xsocket(lsa->sa.sa_family, SOCK_DGRAM, 0); | |
| xbind(udps, &lsa->sa, lsa->len); | |
| - | // xlisten(udps, 50); - ?!! DGRAM sockets are never listened on I think? |
| + | /* xlisten(udps, 50); - ?!! DGRAM sockets are never listened on I think? */ |
| bb_info_msg("Accepting UDP packets on %s", | |
| xmalloc_sockaddr2dotted(&lsa->sa, lsa->len)); | |
| while (1) { | |
| - | fd_set fdset; |
| int r; | |
| - | |
| - | FD_ZERO(&fdset); |
| - | FD_SET(udps, &fdset); |
| - | // Block until a message arrives |
| - | // FIXME: Fantastic. select'ing on just one fd?? |
| - | // Why no just block on it doing recvfrom() ? |
| - | r = select(udps + 1, &fdset, NULL, NULL, NULL); |
| - | if (r < 0) |
| - | bb_perror_msg_and_die("select error"); |
| - | if (r == 0) |
| - | bb_perror_msg_and_die("select spurious return"); |
| - | |
| - | /* Can this test ever be false? - yes */ |
| - | if (FD_ISSET(udps, &fdset)) { |
| - | socklen_t fromlen = lsa->len; |
| + | socklen_t fromlen = lsa->len; |
| // FIXME: need to get *DEST* address (to which of our addresses | |
| // this query was directed), and reply from the same address. | |
| // Or else we can exhibit usual UDP ugliness: | |
| // [ip1.multihomed.ip2] <= query to ip1 <= peer | |
| // [ip1.multihomed.ip2] => reply from ip2 => peer (confused) | |
| - | r = recvfrom(udps, buf, sizeof(buf), 0, &lsa->sa, &fromlen); |
| - | if (OPT_verbose) |
| - | bb_info_msg("Got UDP packet"); |
| - | |
| - | if (r < 12 || r > 512) { |
| - | bb_error_msg("invalid packet size"); |
| - | continue; |
| - | } |
| - | if (r <= 0) |
| - | continue; |
| - | r = process_packet(buf); |
| - | if (r <= 0) |
| - | continue; |
| - | sendto(udps, buf, r, 0, &lsa->sa, fromlen); |
| + | r = recvfrom(udps, buf, sizeof(buf), 0, &lsa->sa, &fromlen); |
| + | if (OPT_verbose) |
| + | bb_info_msg("Got UDP packet"); |
| + | if (r < 12 || r > 512) { |
| + | bb_error_msg("invalid packet size"); |
| + | continue; |
| } | |
| + | r = process_packet(buf); |
| + | if (r <= 0) |
| + | continue; |
| + | sendto(udps, buf, r, 0, &lsa->sa, fromlen); |
| } | |
| } | |