Example #1
0
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);
Example #2
0
int getaddrinfo(const char *host, const char *serv, const struct addrinfo *hint, struct addrinfo **res)
{
	int flags = hint ? hint->ai_flags : 0;
	int family = hint ? hint->ai_family : AF_UNSPEC;
	int type = hint ? hint->ai_socktype : 0;
	int proto = hint ? hint->ai_protocol : 0;
	unsigned long port = 0;
	struct aibuf *buf;
	union sa sa = {{0}};
	unsigned char reply[1024];
	int i, j;
	char line[512];
	FILE *f, _f;
	unsigned char _buf[1024];
	char *z;
	int result;
	int cnt;

	if (host && strlen(host)>255) return EAI_NONAME;
	if (serv && strlen(serv)>32) return EAI_SERVICE;

	if (type && !proto)
		proto = type==SOCK_DGRAM ? IPPROTO_UDP : IPPROTO_TCP;
	if (!type && proto)
		type = proto==IPPROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;

	if (serv) {
		if (!*serv) return EAI_SERVICE;
		port = strtoul(serv, &z, 10);
		if (!*z && port > 65535) return EAI_SERVICE;
		if (!port) {
			size_t servlen = strlen(serv);
			char *end = line;

			if (flags & AI_NUMERICSERV) return EAI_SERVICE;

			f = __fopen_rb_ca("/etc/services", &_f, _buf, sizeof _buf);
			if (!f) return EAI_SERVICE;
			while (fgets(line, sizeof line, f)) {
				if (strncmp(line, serv, servlen) || !isspace(line[servlen]))
					continue;
				port = strtoul(line+servlen, &end, 10);
				if (strncmp(end, proto==IPPROTO_UDP ? "/udp" : "/tcp", 4))
					continue;
				break;
			}
			__fclose_ca(f);
			if (feof(f)) return EAI_SERVICE;
		}
		port = htons(port);
	}

	if (!host) {
		if (family == AF_UNSPEC) family = AF_INET;
		buf = calloc(sizeof *buf, 1+EXTRA);
		if (!buf) return EAI_MEMORY;
		buf->ai.ai_protocol = proto;
		buf->ai.ai_socktype = type;
		buf->ai.ai_addr = (void *)&buf->sa;
		buf->ai.ai_addrlen = family==AF_INET6 ? sizeof sa.sin6 : sizeof sa.sin;
		buf->ai.ai_family = family;
		buf->sa.sin.sin_family = family;
		buf->sa.sin.sin_port = port;
		if (!(flags & AI_PASSIVE)) {
			if (family == AF_INET) {
				0[(uint8_t*)&buf->sa.sin.sin_addr.s_addr]=127;
				3[(uint8_t*)&buf->sa.sin.sin_addr.s_addr]=1;
			} else buf[0].sa.sin6.sin6_addr.s6_addr[15] = 1;
		}
		*res = &buf->ai;
		return 0;
	}

	if (!*host) return EAI_NONAME;

	/* Try as a numeric address */
	if (__ipparse(&sa, family, host) >= 0) {
		buf = calloc(sizeof *buf, 1+EXTRA);
		if (!buf) return EAI_MEMORY;
		family = sa.sin.sin_family;
		buf->ai.ai_protocol = proto;
		buf->ai.ai_socktype = type;
		buf->ai.ai_addr = (void *)&buf->sa;
		buf->ai.ai_addrlen = family==AF_INET6 ? sizeof sa.sin6 : sizeof sa.sin;
		buf->ai.ai_family = family;
		buf->ai.ai_canonname = (char *)host;
		buf->sa = sa;
		buf->sa.sin.sin_port = port;
		*res = &buf->ai;
		return 0;
	}

	if (flags & AI_NUMERICHOST) return EAI_NONAME;

	f = __fopen_rb_ca("/etc/hosts", &_f, _buf, sizeof _buf);
	if (f) while (fgets(line, sizeof line, f)) {
		char *p;
		size_t l = strlen(host);

		if ((p=strchr(line, '#'))) *p++='\n', *p=0;
		for(p=line+1; (p=strstr(p, host)) &&
			(!isspace(p[-1]) || !isspace(p[l])); p++);
		if (!p) continue;
		__fclose_ca(f);

		/* Isolate IP address to parse */
		for (p=line; *p && !isspace(*p); p++);
		*p++ = 0;
		if (__ipparse(&sa, family, line) < 0) return EAI_NONAME;

		/* Allocate and fill result buffer */
		buf = calloc(sizeof *buf, 1+EXTRA);
		if (!buf) return EAI_MEMORY;
		family = sa.sin.sin_family;
		buf->ai.ai_protocol = proto;
		buf->ai.ai_socktype = type;
		buf->ai.ai_addr = (void *)&buf->sa;
		buf->ai.ai_addrlen = family==AF_INET6 ? sizeof sa.sin6 : sizeof sa.sin;
		buf->ai.ai_family = family;
		buf->sa = sa;
		buf->sa.sin.sin_port = port;

		/* Extract first name as canonical name */
		for (; *p && isspace(*p); p++);
		buf->ai.ai_canonname = (void *)(buf+1);
		snprintf(buf->ai.ai_canonname, 256, "%s", p);
		for (p=buf->ai.ai_canonname; *p && !isspace(*p); p++);
		*p = 0;
		if (!is_valid(buf->ai.ai_canonname))
			buf->ai.ai_canonname = 0;

		*res = &buf->ai;
		return 0;
	}
	if (f) __fclose_ca(f);

#if 0
	f = __fopen_rb_ca("/etc/resolv.conf", &_f, _buf, sizeof _buf);
	if (f) while (fgets(line, sizeof line, f)) {
		if (!isspace(line[10]) || (strncmp(line, "search", 6)
			&& strncmp(line, "domain", 6))) continue;
	}
	if (f) __fclose_ca(f);
#endif

	/* Perform one or more DNS queries for host */
	memset(reply, 0, sizeof reply);
	result = __dns_query(reply, host, family, 0);
	if (result < 0) return result;

	cnt = __dns_count_addrs(reply, result);
	if (cnt <= 0) return EAI_NONAME;

	buf = calloc(sizeof *buf, cnt+EXTRA);
	if (!buf) return EAI_MEMORY;

	i = 0;
	if (family != AF_INET6) {
		j = __dns_get_rr(&buf[i].sa.sin.sin_addr, sizeof *buf, 4, cnt-i, reply, RR_A, 0);
		while (j--) buf[i++].sa.sin.sin_family = AF_INET;
	}
	if (family != AF_INET) {
		j = __dns_get_rr(&buf[i].sa.sin6.sin6_addr, sizeof *buf, 16, cnt-i, reply, RR_AAAA, 0);
		while (j--) buf[i++].sa.sin.sin_family = AF_INET6;
	}
	if (result>1) {
		j = __dns_get_rr(&buf[i].sa.sin.sin_addr, sizeof *buf, 4, cnt-i, reply+512, RR_A, 0);
		while (j--) buf[i++].sa.sin.sin_family = AF_INET;
		j = __dns_get_rr(&buf[i].sa.sin6.sin6_addr, sizeof *buf, 16, cnt-i, reply+512, RR_AAAA, 0);
		while (j--) buf[i++].sa.sin.sin_family = AF_INET6;
	}

	if (__dns_get_rr((void *)&buf[cnt], 0, 256, 1, reply, RR_CNAME, 1) < 0)
		strcpy((void *)&buf[cnt], host);

	for (i=0; i<cnt; i++) {
		buf[i].ai.ai_protocol = proto;
		buf[i].ai.ai_socktype = type;
		buf[i].ai.ai_addr = (void *)&buf[i].sa;
		buf[i].ai.ai_addrlen = buf[i].sa.sin.sin_family==AF_INET6
			? sizeof sa.sin6 : sizeof sa.sin;
		buf[i].ai.ai_family = buf[i].sa.sin.sin_family;
		buf[i].sa.sin.sin_port = port;
		buf[i].ai.ai_next = &buf[i+1].ai;
		buf[i].ai.ai_canonname = (void *)&buf[cnt];
	}
	buf[cnt-1].ai.ai_next = 0;
	*res = &buf->ai;

	return 0;
}