slirp: Add dns6 resolution (1d17654e) · Commits · SUMMER2020 / students / proj-2021291

slirp/ip6.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -26,6 +26,12 @@
		0x00, 0x00, 0x00, 0x00,\
		0x00, 0x00, 0x00, 0x02 } }

		#define ZERO_ADDR { .s6_addr = \
		{ 0x00, 0x00, 0x00, 0x00,\
		0x00, 0x00, 0x00, 0x00,\
		0x00, 0x00, 0x00, 0x00,\
		0x00, 0x00, 0x00, 0x00 } }

		static inline bool in6_equal(const struct in6_addr a, const struct in6_addr b)
		{
		return memcmp(a, b, sizeof(*a)) == 0;
		@@ -84,6 +90,9 @@ static inline bool in6_equal_mach(const struct in6_addr *a,
		#define in6_solicitednode_multicast(a)\
		(in6_equal_net(a, &(struct in6_addr)SOLICITED_NODE_PREFIX, 104))

		#define in6_zero(a)\
		(in6_equal(a, &(struct in6_addr)ZERO_ADDR))

		/* Compute emulated host MAC address from its ipv6 address */
		static inline void in6_compute_ethaddr(struct in6_addr ip,
		uint8_t eth[ETH_ALEN])

slirp/libslirp.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -7,6 +7,7 @@ struct Slirp;
		typedef struct Slirp Slirp;

		int get_dns_addr(struct in_addr *pdns_addr);
		int get_dns6_addr(struct in6_addr *pdns6_addr);

		Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
		struct in_addr vnetmask, struct in_addr vhost,

slirp/slirp.c

+57 −22

Original line number	Diff line number	Diff line
		@@ -46,7 +46,9 @@ static QTAILQ_HEAD(slirp_instances, Slirp) slirp_instances =
		QTAILQ_HEAD_INITIALIZER(slirp_instances);

		static struct in_addr dns_addr;
		static struct in6_addr dns6_addr;
		static u_int dns_addr_time;
		static u_int dns6_addr_time;

		#define TIMEOUT_FAST 2 /* milliseconds */
		#define TIMEOUT_SLOW 499 /* milliseconds */
		@@ -100,6 +102,11 @@ int get_dns_addr(struct in_addr *pdns_addr)
		return 0;
		}

		int get_dns6_addr(struct in6_addr *pdns_addr6)
		{
		return -1;
		}

		static void winsock_cleanup(void)
		{
		WSACleanup();
		@@ -107,36 +114,37 @@ static void winsock_cleanup(void)

		#else

		static struct stat dns_addr_stat;

		static int get_dns_addr_cached(struct in_addr *pdns_addr)
		static int get_dns_addr_cached(void pdns_addr, void cached_addr,
		socklen_t addrlen,
		struct stat cached_stat, u_int cached_time)
		{
		struct stat old_stat;
		if (curtime - dns_addr_time < TIMEOUT_DEFAULT) {
		*pdns_addr = dns_addr;
		if (curtime - *cached_time < TIMEOUT_DEFAULT) {
		memcpy(pdns_addr, cached_addr, addrlen);
		return 0;
		}
		old_stat = dns_addr_stat;
		if (stat("/etc/resolv.conf", &dns_addr_stat) != 0) {
		old_stat = *cached_stat;
		if (stat("/etc/resolv.conf", cached_stat) != 0) {
		return -1;
		}
		if (dns_addr_stat.st_dev == old_stat.st_dev
		&& dns_addr_stat.st_ino == old_stat.st_ino
		&& dns_addr_stat.st_size == old_stat.st_size
		&& dns_addr_stat.st_mtime == old_stat.st_mtime) {
		*pdns_addr = dns_addr;
		if (cached_stat->st_dev == old_stat.st_dev
		&& cached_stat->st_ino == old_stat.st_ino
		&& cached_stat->st_size == old_stat.st_size
		&& cached_stat->st_mtime == old_stat.st_mtime) {
		memcpy(pdns_addr, cached_addr, addrlen);
		return 0;
		}
		return 1;
		}

		static int get_dns_addr_resolv_conf(struct in_addr *pdns_addr)
		static int get_dns_addr_resolv_conf(int af, void pdns_addr, void cached_addr,
		socklen_t addrlen, u_int *cached_time)
		{
		char buff[512];
		char buff2[257];
		FILE *f;
		int found = 0;
		struct in_addr tmp_addr;
		void *tmp_addr = alloca(addrlen);

		f = fopen("/etc/resolv.conf", "r");
		if (!f)
		@@ -147,13 +155,14 @@ static int get_dns_addr_resolv_conf(struct in_addr *pdns_addr)
		#endif
		while (fgets(buff, 512, f) != NULL) {
		if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) {
		if (!inet_aton(buff2, &tmp_addr))
		if (!inet_pton(af, buff2, tmp_addr)) {
		continue;
		}
		/* If it's the first one, set it to dns_addr */
		if (!found) {
		*pdns_addr = tmp_addr;
		dns_addr = tmp_addr;
		dns_addr_time = curtime;
		memcpy(pdns_addr, tmp_addr, addrlen);
		memcpy(cached_addr, tmp_addr, addrlen);
		*cached_time = curtime;
		}
		#ifdef DEBUG
		else
		@@ -166,8 +175,14 @@ static int get_dns_addr_resolv_conf(struct in_addr *pdns_addr)
		break;
		}
		#ifdef DEBUG
		else
		fprintf(stderr, "%s", inet_ntoa(tmp_addr));
		else {
		char s[INET6_ADDRSTRLEN];
		char *res = inet_ntop(af, tmp_addr, s, sizeof(s));
		if (!res) {
		res = "(string conversion error)";
		}
		fprintf(stderr, "%s", res);
		}
		#endif
		}
		}
		@@ -179,14 +194,34 @@ static int get_dns_addr_resolv_conf(struct in_addr *pdns_addr)

		int get_dns_addr(struct in_addr *pdns_addr)
		{
		static struct stat dns_addr_stat;

		if (dns_addr.s_addr != 0) {
		int ret;
		ret = get_dns_addr_cached(pdns_addr);
		ret = get_dns_addr_cached(pdns_addr, &dns_addr, sizeof(dns_addr),
		&dns_addr_stat, &dns_addr_time);
		if (ret <= 0) {
		return ret;
		}
		}
		return get_dns_addr_resolv_conf(AF_INET, pdns_addr, &dns_addr,
		sizeof(dns_addr), &dns_addr_time);
		}

		int get_dns6_addr(struct in6_addr *pdns6_addr)
		{
		static struct stat dns6_addr_stat;

		if (!in6_zero(&dns6_addr)) {
		int ret;
		ret = get_dns_addr_cached(pdns6_addr, &dns6_addr, sizeof(dns6_addr),
		&dns6_addr_stat, &dns6_addr_time);
		if (ret <= 0) {
		return ret;
		}
		}
		return get_dns_addr_resolv_conf(pdns_addr);
		return get_dns_addr_resolv_conf(AF_INET6, pdns6_addr, &dns6_addr,
		sizeof(dns6_addr), &dns6_addr_time);
		}

		#endif

slirp/socket.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -816,9 +816,9 @@ void sotranslate_out(struct socket so, struct sockaddr_storage addr)
		if (in6_equal_net(&so->so_faddr6, &slirp->vprefix_addr6,
		slirp->vprefix_len)) {
		if (in6_equal(&so->so_faddr6, &slirp->vnameserver_addr6)) {
		/if (get_dns_addr(&addr) < 0) {/ /* TODO */
		if (get_dns6_addr(&sin6->sin6_addr) < 0) {
		sin6->sin6_addr = in6addr_loopback;
		/}/
		}
		} else {
		sin6->sin6_addr = in6addr_loopback;
		}