[Qemu-devel] [PATCHv2 0/5] ipv4-only and ipv6-only support

[Qemu-devel] [PATCHv2 0/5] ipv4-only and ipv6-only support

[Samuel Thibault]

Hello,

This series gathers the patches to enable ipv4-only and ipv6-only support: it
adds the discussed ipv4 and ipv6 options to select which is enabled, and adds
support for ipv6 dns translation.

Changes since previous submission:

- code layout
- cope with inet_ntop returning NULL
- move static variables to function using them.
- remove superfluous parenthesis.
- fix coding style
- explicit that qemu options can take ipv[46]=on|off

Samuel Thibault (5):
  slirp: Allow disabling IPv4 or IPv6
  slirp: Split get_dns_addr
  slirp: Add dns6 resolution
  slirp: Support link-local DNS addresses
  slirp: Add RDNSS advertisement

 net/slirp.c       |  36 ++++++++++++---
 qapi-schema.json  |   8 ++++
 qemu-options.hx   |   8 +++-
 slirp/ip6.h       |   9 ++++
 slirp/ip6_icmp.c  |  27 +++++++++--
 slirp/ip6_icmp.h  |  12 ++++-
 slirp/ip6_input.c |   5 +++
 slirp/ip_input.c  |   4 ++
 slirp/libslirp.h  |   4 +-
 slirp/slirp.c     | 132 ++++++++++++++++++++++++++++++++++++++++++------------
 slirp/slirp.h     |   2 +
 slirp/socket.c    |   4 +-
 12 files changed, 207 insertions(+), 44 deletions(-)

-- 
2.8.0.rc3

[Qemu-devel] [PATCHv2 1/5] slirp: Allow disabling IPv4 or IPv6

[Samuel Thibault]

Add ipv4 and ipv6 boolean options, so the user can setup IPv4-only and
IPv6-only network environments.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

---

Changes since previous versions:

- fix coding style
- explicit that qemu options can take ipv[46]=on|off
---
 net/slirp.c       | 36 ++++++++++++++++++++++++++++++------
 qapi-schema.json  |  8 ++++++++
 qemu-options.hx   |  8 ++++++--
 slirp/ip6_icmp.c  |  8 ++++++++
 slirp/ip6_input.c |  5 +++++
 slirp/ip_input.c  |  4 ++++
 slirp/libslirp.h  |  3 ++-
 slirp/slirp.c     | 10 +++++++++-
 slirp/slirp.h     |  2 ++
 9 files changed, 74 insertions(+), 10 deletions(-)

diff --git a/net/slirp.c b/net/slirp.c
index 791a8f7..31630f0 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -136,8 +136,8 @@ static NetClientInfo net_slirp_info = {
 
 static int net_slirp_init(NetClientState *peer, const char *model,
                           const char *name, int restricted,
-                          const char *vnetwork, const char *vhost,
-                          const char *vprefix6, int vprefix6_len,
+                          bool ipv4, const char *vnetwork, const char *vhost,
+                          bool ipv6, const char *vprefix6, int vprefix6_len,
                           const char *vhost6,
                           const char *vhostname, const char *tftp_export,
                           const char *bootfile, const char *vdhcp_start,
@@ -165,6 +165,19 @@ static int net_slirp_init(NetClientState *peer, const char *model,
     char *end;
     struct slirp_config_str *config;
 
+    if (!ipv4 && (vnetwork || vhost || vnameserver)) {
+        return -1;
+    }
+
+    if (!ipv6 && (vprefix6 || vhost6 || vnameserver6)) {
+        return -1;
+    }
+
+    if (!ipv4 && !ipv6) {
+        /* It doesn't make sense to disable both */
+        return -1;
+    }
+
     if (!tftp_export) {
         tftp_export = legacy_tftp_prefix;
     }
@@ -309,8 +322,8 @@ static int net_slirp_init(NetClientState *peer, const char *model,
 
     s = DO_UPCAST(SlirpState, nc, nc);
 
-    s->slirp = slirp_init(restricted, net, mask, host,
-                          ip6_prefix, vprefix6_len, ip6_host,
+    s->slirp = slirp_init(restricted, ipv4, net, mask, host,
+                          ipv6, ip6_prefix, vprefix6_len, ip6_host,
                           vhostname, tftp_export, bootfile, dhcp,
                           dns, ip6_dns, dnssearch, s);
     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
@@ -813,10 +826,20 @@ int net_init_slirp(const NetClientOptions *opts, const char *name,
     int ret;
     const NetdevUserOptions *user;
     const char **dnssearch;
+    bool ipv4 = true, ipv6 = true;
 
     assert(opts->type == NET_CLIENT_OPTIONS_KIND_USER);
     user = opts->u.user.data;
 
+    if ((user->has_ipv6 && user->ipv6 && !user->has_ipv4) ||
+        (user->has_ipv4 && !user->ipv4)) {
+        ipv4 = 0;
+    }
+    if ((user->has_ipv4 && user->ipv4 && !user->has_ipv6) ||
+        (user->has_ipv6 && !user->ipv6)) {
+        ipv6 = 0;
+    }
+
     vnet = user->has_net ? g_strdup(user->net) :
            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
            NULL;
@@ -828,8 +851,9 @@ int net_init_slirp(const NetClientOptions *opts, const char *name,
     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
     net_init_slirp_configs(user->guestfwd, 0);
 
-    ret = net_slirp_init(peer, "user", name, user->q_restrict, vnet,
-                         user->host, user->ipv6_prefix, user->ipv6_prefixlen,
+    ret = net_slirp_init(peer, "user", name, user->q_restrict,
+                         ipv4, vnet, user->host,
+                         ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
                          user->ipv6_host, user->hostname, user->tftp,
                          user->bootfile, user->dhcpstart,
                          user->dns, user->ipv6_dns, user->smb,
diff --git a/qapi-schema.json b/qapi-schema.json
index e58f6a9..54634c4 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2425,6 +2425,12 @@
 #
 # @restrict: #optional isolate the guest from the host
 #
+# @ipv4: #optional whether to support IPv4, default true for enabled
+#        (since 2.6)
+#
+# @ipv6: #optional whether to support IPv6, default true for enabled
+#        (since 2.6)
+#
 # @ip: #optional legacy parameter, use net= instead
 #
 # @net: #optional IP network address that the guest will see, in the
@@ -2473,6 +2479,8 @@
   'data': {
     '*hostname':  'str',
     '*restrict':  'bool',
+    '*ipv4':      'bool',
+    '*ipv6':      'bool',
     '*ip':        'str',
     '*net':       'str',
     '*host':      'str',
diff --git a/qemu-options.hx b/qemu-options.hx
index a770086..789d9f6 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -1551,8 +1551,9 @@ DEF("smb", HAS_ARG, QEMU_OPTION_smb, "", QEMU_ARCH_ALL)
 
 DEF("netdev", HAS_ARG, QEMU_OPTION_netdev,
 #ifdef CONFIG_SLIRP
-    "-netdev user,id=str[,net=addr[/mask]][,host=addr][,ipv6-net=addr[/int]]\n"
-    "         [,ipv6-host=addr][,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
+    "-netdev user,id=str[,ipv4[=on|off]][,net=addr[/mask]][,host=addr]\n"
+    "         [,ipv6[=on|off]][,ipv6-net=addr[/int]][,ipv6-host=addr]\n"
+    "         [,restrict=on|off][,hostname=host][,dhcpstart=addr]\n"
     "         [,dns=addr][,ipv6-dns=addr][,dnssearch=domain][,tftp=dir]\n"
     "         [,bootfile=f][,hostfwd=rule][,guestfwd=rule]"
 #ifndef _WIN32
@@ -1701,6 +1702,9 @@ Connect user mode stack to VLAN @var{n} (@var{n} = 0 is the default).
 @itemx name=@var{name}
 Assign symbolic name for use in monitor commands.
 
+@option{ipv4} and @option{ipv6} specify that either IPv4 or IPv6 must
+be enabled.  If neither is specified both protocols are enabled.
+
 @item net=@var{addr}[/@var{mask}]
 Set IP network address the guest will see. Optionally specify the netmask,
 either in the form a.b.c.d or as number of valid top-most bits. Default is
diff --git a/slirp/ip6_icmp.c b/slirp/ip6_icmp.c
index 9d61349..09571bc 100644
--- a/slirp/ip6_icmp.c
+++ b/slirp/ip6_icmp.c
@@ -24,6 +24,10 @@ static void ra_timer_handler(void *opaque)
 
 void icmp6_init(Slirp *slirp)
 {
+    if (!slirp->in6_enabled) {
+        return;
+    }
+
     slirp->ra_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, ra_timer_handler, slirp);
     timer_mod(slirp->ra_timer,
               qemu_clock_get_ms(QEMU_CLOCK_VIRTUAL) + NDP_Interval);
@@ -31,6 +35,10 @@ void icmp6_init(Slirp *slirp)
 
 void icmp6_cleanup(Slirp *slirp)
 {
+    if (!slirp->in6_enabled) {
+        return;
+    }
+
     timer_del(slirp->ra_timer);
     timer_free(slirp->ra_timer);
 }
diff --git a/slirp/ip6_input.c b/slirp/ip6_input.c
index c0b11e7..ac2e3ea 100644
--- a/slirp/ip6_input.c
+++ b/slirp/ip6_input.c
@@ -24,6 +24,11 @@ void ip6_cleanup(Slirp *slirp)
 void ip6_input(struct mbuf *m)
 {
     struct ip6 *ip6;
+    Slirp *slirp = m->slirp;
+
+    if (!slirp->in6_enabled) {
+        goto bad;
+    }
 
     DEBUG_CALL("ip6_input");
     DEBUG_ARG("m = %lx", (long)m);
diff --git a/slirp/ip_input.c b/slirp/ip_input.c
index b464f6b..cdd5483 100644
--- a/slirp/ip_input.c
+++ b/slirp/ip_input.c
@@ -80,6 +80,10 @@ ip_input(struct mbuf *m)
 	register struct ip *ip;
 	int hlen;
 
+	if (!slirp->in_enabled) {
+		goto bad;
+	}
+
 	DEBUG_CALL("ip_input");
 	DEBUG_ARG("m = %p", m);
 	DEBUG_ARG("m_len = %d", m->m_len);
diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index c4b25c9..127aa41 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -8,8 +8,9 @@ typedef struct Slirp Slirp;
 
 int get_dns_addr(struct in_addr *pdns_addr);
 
-Slirp *slirp_init(int restricted, struct in_addr vnetwork,
+Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
                   struct in_addr vnetmask, struct in_addr vhost,
+                  bool in6_enabled,
                   struct in6_addr vprefix_addr6, uint8_t vprefix_len,
                   struct in6_addr vhost6, const char *vhostname,
                   const char *tftp_path, const char *bootfile,
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 3481fcc..cefb9dc 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -200,8 +200,9 @@ static void slirp_init_once(void)
 static void slirp_state_save(QEMUFile *f, void *opaque);
 static int slirp_state_load(QEMUFile *f, void *opaque, int version_id);
 
-Slirp *slirp_init(int restricted, struct in_addr vnetwork,
+Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
                   struct in_addr vnetmask, struct in_addr vhost,
+                  bool in6_enabled,
                   struct in6_addr vprefix_addr6, uint8_t vprefix_len,
                   struct in6_addr vhost6, const char *vhostname,
                   const char *tftp_path, const char *bootfile,
@@ -216,6 +217,9 @@ Slirp *slirp_init(int restricted, struct in_addr vnetwork,
     slirp->grand = g_rand_new();
     slirp->restricted = restricted;
 
+    slirp->in_enabled = in_enabled;
+    slirp->in6_enabled = in6_enabled;
+
     if_init(slirp);
     ip_init(slirp);
     ip6_init(slirp);
@@ -694,6 +698,10 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
     int ar_op;
     struct ex_list *ex_ptr;
 
+    if (!slirp->in_enabled) {
+        return;
+    }
+
     ar_op = ntohs(ah->ar_op);
     switch(ar_op) {
     case ARPOP_REQUEST:
diff --git a/slirp/slirp.h b/slirp/slirp.h
index 1abbcc6..c99ebb9 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -180,6 +180,8 @@ struct Slirp {
     u_int last_slowtimo;
     bool do_slowtimo;
 
+    bool in_enabled, in6_enabled;
+
     /* virtual network configuration */
     struct in_addr vnetwork_addr;
     struct in_addr vnetwork_mask;
-- 
2.8.0.rc3

[Qemu-devel] [PATCHv2 2/5] slirp: Split get_dns_addr

[Samuel Thibault]

Separate get_dns_addr into get_dns_addr_cached and get_dns_addr_resolv_conf
to make conversion to IPv6 easier.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>

---
Change since v1: remove superfluous parenthesis.
---
 slirp/slirp.c | 53 ++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 34 insertions(+), 19 deletions(-)

diff --git a/slirp/slirp.c b/slirp/slirp.c
index cefb9dc..4478a43 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -109,7 +109,28 @@ static void winsock_cleanup(void)
 
 static struct stat dns_addr_stat;
 
-int get_dns_addr(struct in_addr *pdns_addr)
+static int get_dns_addr_cached(struct in_addr *pdns_addr)
+{
+    struct stat old_stat;
+    if (curtime - dns_addr_time < TIMEOUT_DEFAULT) {
+        *pdns_addr = dns_addr;
+        return 0;
+    }
+    old_stat = dns_addr_stat;
+    if (stat("/etc/resolv.conf", &dns_addr_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;
+        return 0;
+    }
+    return 1;
+}
+
+static int get_dns_addr_resolv_conf(struct in_addr *pdns_addr)
 {
     char buff[512];
     char buff2[257];
@@ -117,24 +138,6 @@ int get_dns_addr(struct in_addr *pdns_addr)
     int found = 0;
     struct in_addr tmp_addr;
 
-    if (dns_addr.s_addr != 0) {
-        struct stat old_stat;
-        if ((curtime - dns_addr_time) < TIMEOUT_DEFAULT) {
-            *pdns_addr = dns_addr;
-            return 0;
-        }
-        old_stat = dns_addr_stat;
-        if (stat("/etc/resolv.conf", &dns_addr_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;
-            return 0;
-        }
-    }
-
     f = fopen("/etc/resolv.conf", "r");
     if (!f)
         return -1;
@@ -174,6 +177,18 @@ int get_dns_addr(struct in_addr *pdns_addr)
     return 0;
 }
 
+int get_dns_addr(struct in_addr *pdns_addr)
+{
+    if (dns_addr.s_addr != 0) {
+        int ret;
+        ret = get_dns_addr_cached(pdns_addr);
+        if (ret <= 0) {
+            return ret;
+        }
+    }
+    return get_dns_addr_resolv_conf(pdns_addr);
+}
+
 #endif
 
 static void slirp_init_once(void)
-- 
2.8.0.rc3

[Qemu-devel] [PATCHv2 3/5] slirp: Add dns6 resolution

[Samuel Thibault]

This makes get_dns_addr address family-agnostic, thus allowing to add the
IPv6 case.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>

---
Changes since v1:
- code layout
- cope with inet_ntop returning NULL
- move static variables to function using them.
---
 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 8ddfa24..da23de6 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 127aa41..b0cfbc5 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 4478a43..c6bcc6e 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 b836c42..653257d 100644
--- a/slirp/socket.c
+++ b/slirp/socket.c
@@ -796,9 +796,9 @@ 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;
             }
-- 
2.8.0.rc3

[Qemu-devel] [PATCHv2 4/5] slirp: Support link-local DNS addresses

[Samuel Thibault]

They look like fe80::%eth0

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 slirp/libslirp.h |  2 +-
 slirp/slirp.c    | 26 ++++++++++++++++++++++----
 slirp/socket.c   |  2 +-
 3 files changed, 24 insertions(+), 6 deletions(-)

diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index b0cfbc5..81bd139 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -7,7 +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);
+int get_dns6_addr(struct in6_addr *pdns6_addr, unsigned *scope_id);
 
 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 c6bcc6e..c00fa32 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -30,6 +30,10 @@
 #include "hw/hw.h"
 #include "qemu/cutils.h"
 
+#ifndef _WIN32
+#include <net/if.h>
+#endif
+
 /* host loopback address */
 struct in_addr loopback_addr;
 /* host loopback network mask */
@@ -138,13 +142,15 @@ static int get_dns_addr_cached(void *pdns_addr, void *cached_addr,
 }
 
 static int get_dns_addr_resolv_conf(int af, void *pdns_addr, void *cached_addr,
-                                    socklen_t addrlen, u_int *cached_time)
+                                    socklen_t addrlen, unsigned *scope_id,
+                                    u_int *cached_time)
 {
     char buff[512];
     char buff2[257];
     FILE *f;
     int found = 0;
     void *tmp_addr = alloca(addrlen);
+    unsigned if_index;
 
     f = fopen("/etc/resolv.conf", "r");
     if (!f)
@@ -155,6 +161,14 @@ static int get_dns_addr_resolv_conf(int af, void *pdns_addr, void *cached_addr,
 #endif
     while (fgets(buff, 512, f) != NULL) {
         if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) {
+            char *c = strchr(buff2, '%');
+            if (c) {
+                if_index = if_nametoindex(c + 1);
+                *c = '\0';
+            } else {
+                if_index = 0;
+            }
+
             if (!inet_pton(af, buff2, tmp_addr)) {
                 continue;
             }
@@ -162,6 +176,9 @@ static int get_dns_addr_resolv_conf(int af, void *pdns_addr, void *cached_addr,
             if (!found) {
                 memcpy(pdns_addr, tmp_addr, addrlen);
                 memcpy(cached_addr, tmp_addr, addrlen);
+                if (scope_id) {
+                    *scope_id = if_index;
+                }
                 *cached_time = curtime;
             }
 #ifdef DEBUG
@@ -205,10 +222,10 @@ int get_dns_addr(struct in_addr *pdns_addr)
         }
     }
     return get_dns_addr_resolv_conf(AF_INET, pdns_addr, &dns_addr,
-                                    sizeof(dns_addr), &dns_addr_time);
+                                    sizeof(dns_addr), NULL, &dns_addr_time);
 }
 
-int get_dns6_addr(struct in6_addr *pdns6_addr)
+int get_dns6_addr(struct in6_addr *pdns6_addr, unsigned *scope_id)
 {
     static struct stat dns6_addr_stat;
 
@@ -221,7 +238,8 @@ int get_dns6_addr(struct in6_addr *pdns6_addr)
         }
     }
     return get_dns_addr_resolv_conf(AF_INET6, pdns6_addr, &dns6_addr,
-                                    sizeof(dns6_addr), &dns6_addr_time);
+                                    sizeof(dns6_addr),
+                                    scope_id, &dns6_addr_time);
 }
 
 #endif
diff --git a/slirp/socket.c b/slirp/socket.c
index 653257d..896c27e 100644
--- a/slirp/socket.c
+++ b/slirp/socket.c
@@ -796,7 +796,7 @@ 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_dns6_addr(&sin6->sin6_addr) < 0) {
+                if (get_dns6_addr(&sin6->sin6_addr, &sin6->sin6_scope_id) < 0) {
                     sin6->sin6_addr = in6addr_loopback;
                 }
             } else {
-- 
2.8.0.rc3

[Qemu-devel] [PATCHv2 5/5] slirp: Add RDNSS advertisement

[Samuel Thibault]

This adds the RDNSS option to IPv6 router advertisements, so that the guest
can autoconfigure the DNS server address.

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
---
 slirp/ip6_icmp.c | 19 ++++++++++++++++---
 slirp/ip6_icmp.h | 12 ++++++++++--
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/slirp/ip6_icmp.c b/slirp/ip6_icmp.c
index 09571bc..74585d1 100644
--- a/slirp/ip6_icmp.c
+++ b/slirp/ip6_icmp.c
@@ -149,7 +149,8 @@ void ndp_send_ra(Slirp *slirp)
     rip->ip_nh = IPPROTO_ICMPV6;
     rip->ip_pl = htons(ICMP6_NDP_RA_MINLEN
                         + NDPOPT_LINKLAYER_LEN
-                        + NDPOPT_PREFIXINFO_LEN);
+                        + NDPOPT_PREFIXINFO_LEN
+                        + NDPOPT_RDNSS_LEN);
     t->m_len = sizeof(struct ip6) + ntohs(rip->ip_pl);
 
     /* Build ICMPv6 packet */
@@ -167,16 +168,16 @@ void ndp_send_ra(Slirp *slirp)
     ricmp->icmp6_nra.lifetime = htons(NDP_AdvDefaultLifetime);
     ricmp->icmp6_nra.reach_time = htonl(NDP_AdvReachableTime);
     ricmp->icmp6_nra.retrans_time = htonl(NDP_AdvRetransTime);
+    t->m_data += ICMP6_NDP_RA_MINLEN;
 
     /* Source link-layer address (NDP option) */
-    t->m_data += ICMP6_NDP_RA_MINLEN;
     struct ndpopt *opt = mtod(t, struct ndpopt *);
     opt->ndpopt_type = NDPOPT_LINKLAYER_SOURCE;
     opt->ndpopt_len = NDPOPT_LINKLAYER_LEN / 8;
     in6_compute_ethaddr(rip->ip_src, opt->ndpopt_linklayer);
+    t->m_data += NDPOPT_LINKLAYER_LEN;
 
     /* Prefix information (NDP option) */
-    t->m_data += NDPOPT_LINKLAYER_LEN;
     struct ndpopt *opt2 = mtod(t, struct ndpopt *);
     opt2->ndpopt_type = NDPOPT_PREFIX_INFO;
     opt2->ndpopt_len = NDPOPT_PREFIXINFO_LEN / 8;
@@ -188,8 +189,20 @@ void ndp_send_ra(Slirp *slirp)
     opt2->ndpopt_prefixinfo.pref_lt = htonl(NDP_AdvPrefLifetime);
     opt2->ndpopt_prefixinfo.reserved2 = 0;
     opt2->ndpopt_prefixinfo.prefix = slirp->vprefix_addr6;
+    t->m_data += NDPOPT_PREFIXINFO_LEN;
+
+    /* Prefix information (NDP option) */
+    struct ndpopt *opt3 = mtod(t, struct ndpopt *);
+    opt3->ndpopt_type = NDPOPT_RDNSS;
+    opt3->ndpopt_len = NDPOPT_RDNSS_LEN / 8;
+    opt3->ndpopt_rdnss.reserved = 0;
+    opt3->ndpopt_rdnss.lifetime = htonl(2 * NDP_MaxRtrAdvInterval);
+    opt3->ndpopt_rdnss.addr = slirp->vnameserver_addr6;
+    t->m_data += NDPOPT_RDNSS_LEN;
 
     /* ICMPv6 Checksum */
+    t->m_data -= NDPOPT_RDNSS_LEN;
+    t->m_data -= NDPOPT_PREFIXINFO_LEN;
     t->m_data -= NDPOPT_LINKLAYER_LEN;
     t->m_data -= ICMP6_NDP_RA_MINLEN;
     t->m_data -= sizeof(struct ip6);
diff --git a/slirp/ip6_icmp.h b/slirp/ip6_icmp.h
index 9460bf8..2282d29 100644
--- a/slirp/ip6_icmp.h
+++ b/slirp/ip6_icmp.h
@@ -122,6 +122,7 @@ struct ndpopt {
     uint8_t     ndpopt_len;                     /* /!\ In units of 8 octets */
     union {
         unsigned char   linklayer_addr[6];      /* Source/Target Link-layer */
+#define ndpopt_linklayer ndpopt_body.linklayer_addr
         struct prefixinfo {                     /* Prefix Information */
             uint8_t     prefix_length;
 #ifdef HOST_WORDS_BIGENDIAN
@@ -134,19 +135,26 @@ struct ndpopt {
             uint32_t    reserved2;
             struct in6_addr prefix;
         } QEMU_PACKED prefixinfo;
-    } ndpopt_body;
-#define ndpopt_linklayer ndpopt_body.linklayer_addr
 #define ndpopt_prefixinfo ndpopt_body.prefixinfo
+        struct rdnss {
+            uint16_t reserved;
+            uint32_t lifetime;
+            struct in6_addr addr;
+        } QEMU_PACKED rdnss;
+#define ndpopt_rdnss ndpopt_body.rdnss
+    } ndpopt_body;
 } QEMU_PACKED;
 
 /* NDP options type */
 #define NDPOPT_LINKLAYER_SOURCE     1   /* Source Link-Layer Address */
 #define NDPOPT_LINKLAYER_TARGET     2   /* Target Link-Layer Address */
 #define NDPOPT_PREFIX_INFO          3   /* Prefix Information */
+#define NDPOPT_RDNSS                25  /* Recursive DNS Server Address */
 
 /* NDP options size, in octets. */
 #define NDPOPT_LINKLAYER_LEN    8
 #define NDPOPT_PREFIXINFO_LEN   32
+#define NDPOPT_RDNSS_LEN        24
 
 /*
  * Definition of type and code field values.
-- 
2.8.0.rc3

Re: [Qemu-devel] [PATCHv2 1/5] slirp: Allow disabling IPv4 or IPv6

[Thomas Huth]

On 31.03.2016 00:58, Samuel Thibault wrote:
> Add ipv4 and ipv6 boolean options, so the user can setup IPv4-only and
> IPv6-only network environments.
> 
> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> 
> ---
> 
> Changes since previous versions:
> 
> - fix coding style
> - explicit that qemu options can take ipv[46]=on|off
> ---
>  net/slirp.c       | 36 ++++++++++++++++++++++++++++++------
>  qapi-schema.json  |  8 ++++++++
>  qemu-options.hx   |  8 ++++++--
>  slirp/ip6_icmp.c  |  8 ++++++++
>  slirp/ip6_input.c |  5 +++++
>  slirp/ip_input.c  |  4 ++++
>  slirp/libslirp.h  |  3 ++-
>  slirp/slirp.c     | 10 +++++++++-
>  slirp/slirp.h     |  2 ++
>  9 files changed, 74 insertions(+), 10 deletions(-)

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [Qemu-devel] [PATCHv2 3/5] slirp: Add dns6 resolution

[Thomas Huth]

On 31.03.2016 00:58, Samuel Thibault wrote:
> This makes get_dns_addr address family-agnostic, thus allowing to add the
> IPv6 case.
> 
> Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
> 
> ---
> Changes since v1:
> - code layout
> - cope with inet_ntop returning NULL
> - move static variables to function using them.
> ---
>  slirp/ip6.h      |  9 +++++++
>  slirp/libslirp.h |  1 +
>  slirp/slirp.c    | 79 ++++++++++++++++++++++++++++++++++++++++----------------
>  slirp/socket.c   |  4 +--
>  4 files changed, 69 insertions(+), 24 deletions(-)

Reviewed-by: Thomas Huth <thuth@redhat.com>

Re: [Qemu-devel] [PATCHv2 3/5] slirp: Add dns6 resolution

[Samuel Thibault]

Hello,

Thanks for the reviews!

Samuel