#include <limits.h>
#include <string.h>
#include <sys/socket.h>
-#include <sys/select.h>
-#include <sys/time.h>
+#include <poll.h>
#include <netinet/in.h>
#include <time.h>
#include <ctype.h>
#include <unistd.h>
+#include <pthread.h>
+#include <errno.h>
#include "__dns.h"
#include "stdio_impl.h"
#define TIMEOUT 5
-#define RETRY 1
+#define RETRY 1000
#define PACKET_MAX 512
#define PTR_MAX (64 + sizeof ".in-addr.arpa")
+static void cleanup(void *p)
+{
+ close((intptr_t)p);
+}
+
int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt)
{
time_t t0 = time(0);
int fd;
FILE *f, _f;
- unsigned char _buf[64];
+ unsigned char _buf[256];
char line[64], *s, *z;
union {
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
} sa = {0}, ns[3] = {{0}};
- socklen_t sl;
+ socklen_t sl = sizeof sa.sin;
int nns = 0;
- int family = AF_UNSPEC;
+ int family = AF_INET;
unsigned char q[280] = "", *r = dest;
int ql;
int rlen;
int got = 0, failed = 0;
int errcode = EAI_AGAIN;
int i, j;
- struct timeval tv;
- fd_set fds;
+ struct timespec ts;
+ struct pollfd pfd;
int id;
+ int cs;
+
+ pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
/* Construct query template - RR and ID will be filled later */
- if (strlen(name)-1 >= 254U) return -1;
+ if (strlen(name)-1 >= 254U) return EAI_NONAME;
q[2] = q[5] = 1;
strcpy((char *)q+13, name);
for (i=13; q[i]; i=j+1) {
for (j=i; q[j] && q[j] != '.'; j++);
- if (j-i-1u > 62u) return -1;
+ if (j-i-1u > 62u) return EAI_NONAME;
q[i-1] = j-i;
}
q[i+3] = 1;
ql = i+4;
/* Make a reasonably unpredictable id */
- gettimeofday(&tv, 0);
- id = tv.tv_usec + tv.tv_usec/256 & 0xffff;
+ clock_gettime(CLOCK_REALTIME, &ts);
+ id = ts.tv_nsec + ts.tv_nsec/65536UL & 0xffff;
/* Get nameservers from resolv.conf, fallback to localhost */
f = __fopen_rb_ca("/etc/resolv.conf", &_f, _buf, sizeof _buf);
for (s=line+11; isspace(*s); s++);
for (z=s; *z && !isspace(*z); z++);
*z=0;
- if (__ipparse(ns+nns, family, s) < 0) continue;
+ if (__ipparse(ns+nns, AF_UNSPEC, s) < 0) continue;
ns[nns].sin.sin_port = htons(53);
- family = ns[nns++].sin.sin_family;
- sl = family==AF_INET6 ? sizeof sa.sin6 : sizeof sa.sin;
+ if (ns[nns++].sin.sin_family == AF_INET6) {
+ family = AF_INET6;
+ sl = sizeof sa.sin6;
+ }
}
if (f) __fclose_ca(f);
if (!nns) {
- ns[0].sin.sin_family = AF_INET;
+ ns[0].sin.sin_family = family = AF_INET;
ns[0].sin.sin_port = htons(53);
+ ns[0].sin.sin_addr.s_addr = htonl(0x7f000001);
nns=1;
sl = sizeof sa.sin;
}
/* Get local address and open/bind a socket */
sa.sin.sin_family = family;
- fd = socket(family, SOCK_DGRAM, 0);
+ fd = socket(family, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+
+ /* Handle case where system lacks IPv6 support */
+ if (fd < 0 && errno == EAFNOSUPPORT) {
+ if (family != AF_INET6) return EAI_SYSTEM;
+ fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+ family = AF_INET;
+ }
+ if (fd < 0) return EAI_SYSTEM;
+
+ /* Convert any IPv4 addresses in a mixed environment to v4-mapped */
+ if (family == AF_INET6) {
+ setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &(int){0}, sizeof 0);
+ for (i=0; i<nns; i++) {
+ if (ns[i].sin.sin_family != AF_INET) continue;
+ memcpy(ns[i].sin6.sin6_addr.s6_addr+12,
+ &ns[i].sin.sin_addr, 4);
+ memcpy(ns[i].sin6.sin6_addr.s6_addr,
+ "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
+ ns[i].sin6.sin6_family = AF_INET6;
+ ns[i].sin6.sin6_flowinfo = 0;
+ ns[i].sin6.sin6_scope_id = 0;
+ }
+ }
+
+ pthread_cleanup_push(cleanup, (void *)(intptr_t)fd);
+ pthread_setcancelstate(cs, 0);
+
if (bind(fd, (void *)&sa, sl) < 0) {
- close(fd);
- return -1;
+ errcode = EAI_SYSTEM;
+ goto out;
}
- /* Nonblocking to work around Linux UDP select bug */
- fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK);
+
+ pfd.fd = fd;
+ pfd.events = POLLIN;
/* Loop until we timeout; break early on success */
for (; time(0)-t0 < TIMEOUT; ) {
}
/* Wait for a response, or until time to retry */
- FD_ZERO(&fds);
- FD_SET(fd, &fds);
- tv.tv_sec = RETRY;
- tv.tv_usec = 0;
- if (select(fd+1, &fds, 0, 0, &tv) <= 0) continue;
+ if (poll(&pfd, 1, RETRY) <= 0) continue;
/* Process any and all replies */
while (got+failed < rrcnt && (rlen = recvfrom(fd, r, 512, 0,
/* Check to see if we have answers to all queries */
if (got+failed == rrcnt) break;
}
- close(fd);
+out:
+ pthread_cleanup_pop(1);
/* Return the number of results, or an error code if none */
if (got) return got;
return __dns_doqueries(r, a, rr, rrcnt);
}
-
-#define BITOP(a,b,op) \
- ((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a))))
-
-static int decname(char *s, const unsigned char *b, const unsigned char *p)
-{
- /* Remember jump destinations to detect loops and abort */
- size_t seen[PACKET_MAX/8/sizeof(size_t)] = { 0 };
- char *sz = s + HOST_NAME_MAX;
- const unsigned char *pz = b+512;
- for (;;) {
- if (p>=pz) return -1;
- else if (*p&0xc0) {
- int j = (p[0]&1) | p[1];
- if (BITOP(seen, j, &)) return -1;
- BITOP(seen, j, |=);
- p = b + j;
- } else if (*p) {
- if (p+*p+1>=pz || s+*p>=sz) return -1;
- memcpy(s, p+1, *p);
- s += *p+1;
- p += *p+1;
- s[-1] = *p ? '.' : 0;
- } else return 0;
- }
-}
+int __dn_expand(const unsigned char *, const unsigned char *, const unsigned char *, char *, int);
int __dns_get_rr(void *dest, size_t stride, size_t maxlen, size_t limit, const unsigned char *r, int rr, int dec)
{
len = p[8]*256 + p[9];
if (p+len > r+512) return -1;
if (p[1]==rr && len <= maxlen) {
- if (dec && decname(tmp, r, p+10)<0) return -1;
+ if (dec && __dn_expand(r, r+512, p+10, tmp, sizeof tmp)<0)
+ return -1;
if (dest && limit) {
if (dec) strcpy(dest, tmp);
else memcpy(dest, p+10, len);
int found=0, res, i;
static const int p[2][2] = { { 4, RR_A }, { 16, RR_AAAA } };
- while (cnt--) for (i=0; i<2; i++) {
- res = __dns_get_rr(0, 0, p[i][0], -1, r, p[i][1], 0);
- if (res < 0) return res;
- found += res;
+ while (cnt--) {
+ for (i=0; i<2; i++) {
+ res = __dns_get_rr(0, 0, p[i][0], -1, r, p[i][1], 0);
+ if (res < 0) return res;
+ found += res;
+ }
r += 512;
}
return found;
projects / musl / blobdiff