switch standard resolver functions to use the new dns backend

this is the third phase of the "resolver overhaul" project.

this commit removes all of the old dns code, and switches the
__lookup_name backend (used by getaddrinfo, etc.) and the getnameinfo
function to use the newly implemented __res_mkquery and __res_msend
interfaces. for parsing the results, a new callback-based __dns_parse
function, based on __dns_get_rr from the old dns code, is used.

1 files changed, 0 insertions, 282 deletions

diff --git a/src/network/__dns.c b/src/network/__dns.c
deleted file mode 100644
index 97d8031c..00000000
--- a/src/network/__dns.c
+++ /dev/null
@@ -1,282 +0,0 @@
-#include <stdint.h>
-#include <netdb.h>
-#include <stdio.h>
-#include <fcntl.h>
-#include <limits.h>
-#include <string.h>
-#include <sys/socket.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 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[256];
-	char line[64], *s, *z;
-	union {
-		struct sockaddr_in sin;
-		struct sockaddr_in6 sin6;
-	} sa = {0}, ns[3] = {{0}};
-	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 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 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 EAI_NONAME;
-		q[i-1] = j-i;
-	}
-	q[i+3] = 1;
-	ql = i+4;
-
-	/* Make a reasonably unpredictable id */
-	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);
-	if (f) for (nns=0; nns<3 && fgets(line, sizeof line, f); ) {
-		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;
-		if (__ipparse(ns+nns, AF_UNSPEC, s) < 0) continue;
-		ns[nns].sin.sin_port = htons(53);
-		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 = 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|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) {
-		errcode = EAI_SYSTEM;
-		goto out;
-	}
-
-	pfd.fd = fd;
-	pfd.events = POLLIN;
-
-	/* Loop until we timeout; break early on success */
-	for (; time(0)-t0 < TIMEOUT; ) {
-
-		/* Query all configured namservers in parallel */
-		for (i=0; i<rrcnt; i++) if (rr[i]) for (j=0; j<nns; j++) {
-			q[0] = id+i >> 8;
-			q[1] = id+i;
-			q[ql-3] = rr[i];
-			sendto(fd, q, ql, MSG_NOSIGNAL, (void *)&ns[j], sl);
-		}
-
-		/* Wait for a response, or until time to retry */
-		if (poll(&pfd, 1, RETRY) <= 0) continue;
-
-		/* Process any and all replies */
-		while (got+failed < rrcnt && (rlen = recvfrom(fd, r, 512, 0,
-			(void *)&sa, (socklen_t[1]){sl})) >= 2)
-		{
-			/* Ignore replies from addresses we didn't send to */
-			for (i=0; i<nns; i++) if (!memcmp(ns+i, &sa, sl)) break;
-			if (i==nns) continue;
-
-			/* Compute index of the query from id */
-			i = r[0]*256+r[1] - id & 0xffff;
-			if ((unsigned)i >= rrcnt || !rr[i]) continue;
-
-			/* Interpret the result code */
-			switch (r[3] & 15) {
-			case 0:
-				got++;
-				break;
-			case 3:
-				if (1) errcode = EAI_NONAME; else
-			default:
-				errcode = EAI_FAIL;
-				failed++;
-			}
-
-			/* Mark this record as answered */
-			rr[i] = 0;
-			r += 512;
-		}
-
-		/* Check to see if we have answers to all queries */
-		if (got+failed == rrcnt) break;
-	}
-out:
-	pthread_cleanup_pop(1);
-
-	/* Return the number of results, or an error code if none */
-	if (got) return got;
-	return errcode;
-}
-
-static void mkptr4(char *s, const unsigned char *ip)
-{
-	sprintf(s, "%d.%d.%d.%d.in-addr.arpa",
-		ip[3], ip[2], ip[1], ip[0]);
-}
-
-static void mkptr6(char *s, const unsigned char *ip)
-{
-	static const char xdigits[] = "0123456789abcdef";
-	int i;
-	for (i=15; i>=0; i--) {
-		*s++ = xdigits[ip[i]&15]; *s++ = '.';
-		*s++ = xdigits[ip[i]>>4]; *s++ = '.';
-	}
-	strcpy(s, "ip6.arpa");
-}
-
-int __dns_query(unsigned char *r, const void *a, int family, int ptr)
-{
-	char buf[PTR_MAX];
-	int rr[2], rrcnt = 1;
-
-	if (ptr) {
-		if (family == AF_INET6) mkptr6(buf, a);
-		else mkptr4(buf, a);
-		rr[0] = RR_PTR;
-		a = buf;
-	} else if (family == AF_INET6) {
-		rr[0] = RR_AAAA;
-	} else {
-		rr[0] = RR_A;
-		if (family != AF_INET) rr[rrcnt++] = RR_AAAA;
-	}
-
-	return __dns_doqueries(r, a, rr, rrcnt);
-}
-
-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)
-{
-	int qdcount, ancount;
-	const unsigned char *p;
-	char tmp[256];
-	int found = 0;
-	int len;
-
-	if ((r[3]&15)) return 0;
-	p = r+12;
-	qdcount = r[4]*256 + r[5];
-	ancount = r[6]*256 + r[7];
-	if (qdcount+ancount > 64) return -1;
-	while (qdcount--) {
-		while (p-r < 512 && *p-1U < 127) p++;
-		if (*p>193 || (*p==193 && p[1]>254) || p>r+506)
-			return -1;
-		p += 5 + !!*p;
-	}
-	while (ancount--) {
-		while (p-r < 512 && *p-1U < 127) p++;
-		if (*p>193 || (*p==193 && p[1]>254) || p>r+506)
-			return -1;
-		p += 1 + !!*p;
-		len = p[8]*256 + p[9];
-		if (p+len > r+512) return -1;
-		if (p[1]==rr && len <= maxlen) {
-			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);
-				dest = (char *)dest + stride;
-				limit--;
-			}
-			found++;
-		}
-		p += 10 + len;
-	}
-	return found;
-}
-
-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;
-		}
-		r += 512;
-	}
-	return found;
-}