X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fnetwork%2F__dns.c;h=97d8031ca1d50e110d30e12575c2957bca5e682f;hb=6739b13a172aad9c01572c04cadacc99c7041811;hp=b8547bbafe307b41c5ddd6f1f7f112dfebfff5ba;hpb=6fbf8bfd750a5c982b716bea0802692847918951;p=musl

diff --git a/src/network/__dns.c b/src/network/__dns.c
index b8547bba..97d8031c 100644
--- a/src/network/__dns.c
+++ b/src/network/__dns.c
@@ -5,59 +5,68 @@
 #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;
-	int nns;
-	int family;
+	socklen_t sl = sizeof sa.sin;
+	int nns = 0;
+	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);
@@ -67,28 +76,59 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt)
 		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; ) {
@@ -102,11 +142,7 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt)
 		}
 
 		/* 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,
@@ -140,7 +176,8 @@ int __dns_doqueries(unsigned char *dest, const char *name, int *rr, int rrcnt)
 		/* 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;
@@ -184,32 +221,7 @@ int __dns_query(unsigned char *r, const void *a, int family, int ptr)
 	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)
 {
@@ -238,7 +250,8 @@ int __dns_get_rr(void *dest, size_t stride, size_t maxlen, size_t limit, const u
 		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);
@@ -257,10 +270,12 @@ int __dns_count_addrs(const unsigned char *r, int cnt)
 	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;