From 1d17654e762ed1e31bfb16915fd03499c03d2063 Mon Sep 17 00:00:00 2001 From: Samuel Thibault Date: Sun, 20 Mar 2016 15:09:09 +0100 Subject: [PATCH] slirp: Add dns6 resolution This makes get_dns_addr address family-agnostic, thus allowing to add the IPv6 case. Signed-off-by: Samuel Thibault Reviewed-by: Thomas Huth --- slirp/ip6.h | 9 +++++++ slirp/libslirp.h | 1 + slirp/slirp.c | 79 ++++++++++++++++++++++++++++++++++++++++---------------- slirp/socket.c | 4 +-- 4 files changed, 69 insertions(+), 24 deletions(-) diff --git a/slirp/ip6.h b/slirp/ip6.h index 8ddfa242c4..da23de66f1 100644 --- a/slirp/ip6.h +++ b/slirp/ip6.h @@ -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]) diff --git a/slirp/libslirp.h b/slirp/libslirp.h index 127aa41d40..b0cfbc5b0f 100644 --- a/slirp/libslirp.h +++ b/slirp/libslirp.h @@ -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, diff --git a/slirp/slirp.c b/slirp/slirp.c index e63c5e8fc6..197d9f2979 100644 --- a/slirp/slirp.c +++ b/slirp/slirp.c @@ -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 diff --git a/slirp/socket.c b/slirp/socket.c index b336586c7b..8e8de88044 100644 --- a/slirp/socket.c +++ b/slirp/socket.c @@ -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; } -- 2.11.0