X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=src%2Fnetwork%2Fres_msend.c;h=3e018009ebc61e10c3eb24e0e6039e8fac5e01c4;hb=6a209f14ff7273d9429e5153c5b6b1990cb508e3;hp=cded53531f279c5ad642933ccbc21808656ff131;hpb=8312f7f60f9dfe88118163d38b8282abf04aac2f;p=musl

diff --git a/src/network/res_msend.c b/src/network/res_msend.c
index cded5353..3e018009 100644
--- a/src/network/res_msend.c
+++ b/src/network/res_msend.c
@@ -12,6 +12,7 @@
 #include <pthread.h>
 #include "stdio_impl.h"
 #include "syscall.h"
+#include "lookup.h"
 
 static void cleanup(void *p)
 {
@@ -26,18 +27,16 @@ static unsigned long mtime()
 		+ ts.tv_nsec / 1000000;
 }
 
-int __res_msend(int nqueries, const unsigned char *const *queries,
-	const int *qlens, unsigned char *const *answers, int *alens, int asize)
+int __res_msend_rc(int nqueries, const unsigned char *const *queries,
+	const int *qlens, unsigned char *const *answers, int *alens, int asize,
+	const struct resolvconf *conf)
 {
 	int fd;
-	FILE *f, _f;
-	unsigned char _buf[256];
-	char line[64], *s, *z;
-	int timeout = 5000, attempts = 2, retry_interval;
+	int timeout, attempts, retry_interval, servfail_retry;
 	union {
 		struct sockaddr_in sin;
 		struct sockaddr_in6 sin6;
-	} sa = {0}, ns[3] = {{0}};
+	} sa = {0}, ns[MAXNS] = {{0}};
 	socklen_t sl = sizeof sa.sin;
 	int nns = 0;
 	int family = AF_INET;
@@ -50,48 +49,23 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
 
 	pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cs);
 
-	/* Get nameservers from resolv.conf, fallback to localhost */
-	f = __fopen_rb_ca("/etc/resolv.conf", &_f, _buf, sizeof _buf);
-	if (f) for (nns=0; nns<3 && fgets(line, sizeof line, f); ) {
-		if (!strncmp(line, "options", 7) && isspace(line[7])) {
-			unsigned long x;
-			char *p, *z;
-			p = strstr(line, "timeout:");
-			if (p && isdigit(p[8])) {
-				p += 8;
-				x = strtoul(p, &z, 10);
-				if (z != p) timeout = x < 30 ? x*1000 : 30000;
-			}
-			p = strstr(line, "attempts:");
-			if (p && isdigit(p[9])) {
-				p += 9;
-				x = strtoul(p, &z, 10);
-				if (z != p) attempts = x < 10 ? x : 10;
-				if (!attempts) attempts = 1;
-			}
-		}
-		if (strncmp(line, "nameserver", 10) || !isspace(line[10]))
-			continue;
-		for (s=line+11; isspace(*s); s++);
-		for (z=s; *z && !isspace(*z); z++);
-		*z=0;
+	timeout = 1000*conf->timeout;
+	attempts = conf->attempts;
 
-		if (inet_pton(AF_INET, s, &ns[nns].sin.sin_addr)>0) {
+	for (nns=0; nns<conf->nns; nns++) {
+		const struct address *iplit = &conf->ns[nns];
+		if (iplit->family == AF_INET) {
+			memcpy(&ns[nns].sin.sin_addr, iplit->addr, 4);
 			ns[nns].sin.sin_port = htons(53);
-			ns[nns++].sin.sin_family = AF_INET;
-		} else if (inet_pton(AF_INET6, s, &ns[nns].sin6.sin6_addr)>0) {
+			ns[nns].sin.sin_family = AF_INET;
+		} else {
 			sl = sizeof sa.sin6;
+			memcpy(&ns[nns].sin6.sin6_addr, iplit->addr, 16);
 			ns[nns].sin6.sin6_port = htons(53);
-			ns[nns++].sin6.sin6_family = family = AF_INET6;
+			ns[nns].sin6.sin6_scope_id = iplit->scopeid;
+			ns[nns].sin6.sin6_family = family = AF_INET6;
 		}
 	}
-	if (f) __fclose_ca(f);
-	if (!nns) {
-		ns[0].sin.sin_family = AF_INET;
-		ns[0].sin.sin_port = htons(53);
-		ns[0].sin.sin_addr.s_addr = htonl(0x7f000001);
-		nns=1;
-	}
 
 	/* Get local address and open/bind a socket */
 	sa.sin.sin_family = family;
@@ -102,7 +76,11 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
 		fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
 		family = AF_INET;
 	}
-	if (fd < 0 || bind(fd, (void *)&sa, sl) < 0) return -1;
+	if (fd < 0 || bind(fd, (void *)&sa, sl) < 0) {
+		if (fd >= 0) close(fd);
+		pthread_setcancelstate(cs, 0);
+		return -1;
+	}
 
 	/* Past this point, there are no errors. Each individual query will
 	 * yield either no reply (indicated by zero length) or an answer
@@ -131,6 +109,7 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
 	pfd.fd = fd;
 	pfd.events = POLLIN;
 	retry_interval = timeout / attempts;
+	next = 0;
 	t0 = t2 = mtime();
 	t1 = t2 - retry_interval;
 
@@ -144,6 +123,7 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
 							qlens[i], MSG_NOSIGNAL,
 							(void *)&ns[j], sl);
 			t1 = t2;
+			servfail_retry = 2 * nqueries;
 		}
 
 		/* Wait for a response, or until time to retry */
@@ -152,12 +132,12 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
 		while ((rlen = recvfrom(fd, answers[next], asize, 0,
 		  (void *)&sa, (socklen_t[1]){sl})) >= 0) {
 
-			/* Ignore non-identifiable packets (no query id) */
-			if (rlen < 2) continue;
+			/* Ignore non-identifiable packets */
+			if (rlen < 4) continue;
 
 			/* Ignore replies from addresses we didn't send to */
-			for (i=0; i<nns && memcmp(ns+i, &sa, sl); i++);
-			if (i==nns) continue;
+			for (j=0; j<nns && memcmp(ns+j, &sa, sl); j++);
+			if (j==nns) continue;
 
 			/* Find which query this answer goes with, if any */
 			for (i=next; i<nqueries && (
@@ -166,6 +146,22 @@ int __res_msend(int nqueries, const unsigned char *const *queries,
 			if (i==nqueries) continue;
 			if (alens[i]) continue;
 
+			/* Only accept positive or negative responses;
+			 * retry immediately on server failure, and ignore
+			 * all other codes such as refusal. */
+			switch (answers[next][3] & 15) {
+			case 0:
+			case 3:
+				break;
+			case 2:
+				if (servfail_retry && servfail_retry--)
+					sendto(fd, queries[i],
+						qlens[i], MSG_NOSIGNAL,
+						(void *)&ns[j], sl);
+			default:
+				continue;
+			}
+
 			/* Store answer in the right slot, or update next
 			 * available temp slot if it's already in place. */
 			alens[i] = rlen;
@@ -182,3 +178,11 @@ out:
 
 	return 0;
 }
+
+int __res_msend(int nqueries, const unsigned char *const *queries,
+	const int *qlens, unsigned char *const *answers, int *alens, int asize)
+{
+	struct resolvconf conf;
+	if (__get_resolv_conf(&conf, 0, 0) < 0) return -1;
+	return __res_msend_rc(nqueries, queries, qlens, answers, alens, asize, &conf);
+}