sun: Detect correct broadcast address as RTM_NEWADDR lies

I suspect this is because the broadcast address needs to be set
after the address, but RTM_NEWADDR is triggered from adding the
address.

While here, actually set the broadcast address requested
for IPv4 and simplify the code.

diff --git a/src/if-sun.c b/src/if-sun.c
index 191e0e6887900333783457a23fb5464a83999461..9ab81c4812162dbf89b9d2497a57813fd3faaa70 100644 (file)
--- a/src/if-sun.c
+++ b/src/if-sun.c
@@ -845,6 +845,21 @@ if_getalias(struct interface *ifp, const struct sockaddr *sa, char *alias)
        return found;
 }
 
+static int
+if_getbrdaddr(struct dhcpcd_ctx *ctx, const char *ifname, struct in_addr *brd)
+{
+       struct lifreq lifr = { 0 };
+       int r;
+
+       memset(&lifr, 0, sizeof(lifr));
+       strlcpy(lifr.lifr_name, ifname, sizeof(lifr.lifr_name));
+       errno = 0;
+       r = ioctl(ctx->pf_inet_fd, SIOCGLIFBRDADDR, &lifr, sizeof(lifr));
+       if (r != -1)
+               COPYOUT(*brd, (struct sockaddr *)&lifr.lifr_broadaddr);
+       return r;
+}
+
 static void
 if_ifa(struct dhcpcd_ctx *ctx, const struct ifa_msghdr *ifam)
 {
@@ -908,6 +923,11 @@ if_ifa(struct dhcpcd_ctx *ctx, const struct ifa_msghdr *ifam)
                        if (ia == NULL)
                                return;
                        strlcpy(ifalias, ia->alias, sizeof(ifalias));
+               } else if (bcast.s_addr == INADDR_ANY) {
+                       /* Work around a bug where broadcast
+                        * address is not correctly reported. */
+                       if (if_getbrdaddr(ctx, ifalias, &bcast) == -1)
+                               return;
                }
                flags = if_addrflags(ifp, &addr, ifalias);
                if (ifam->ifam_type == RTM_DELADDR) {
@@ -1035,7 +1055,8 @@ if_octetstr(char *buf, const Octet_t *o, ssize_t len)
 
 static int
 if_addaddr(int fd, const char *ifname,
-    struct sockaddr_storage *addr, struct sockaddr_storage *mask)
+    struct sockaddr_storage *addr, struct sockaddr_storage *mask,
+    struct sockaddr_storage *brd)
 {
        struct lifreq           lifr;
 
@@ -1052,6 +1073,13 @@ if_addaddr(int fd, const char *ifname,
        if (ioctl(fd, SIOCSLIFADDR, &lifr) == -1)
                return -1;
 
+       /* Then assign the broadcast address. */
+       if (brd != NULL) {
+               lifr.lifr_broadaddr = *brd;
+               if (ioctl(fd, SIOCSLIFBRDADDR, &lifr) == -1)
+                       return -1;
+       }
+
        /* Now bring it up. */
        if (ioctl(fd, SIOCGLIFFLAGS, &lifr) == -1)
                return -1;
@@ -1205,15 +1233,11 @@ out:
 static int
 if_unplumbif(const struct dhcpcd_ctx *ctx, int af, const char *ifname)
 {
-       struct sockaddr_storage         addr, mask;
+       struct sockaddr_storage         addr = { .ss_family = af };
        int                             fd;
 
        /* For the time being, don't unplumb the interface, just
         * set the address to zero. */
-       memset(&addr, 0, sizeof(addr));
-       addr.ss_family = af;
-       memset(&mask, 0, sizeof(mask));
-       mask.ss_family = af;
        switch (af) {
 #ifdef INET
        case AF_INET:
@@ -1234,7 +1258,8 @@ if_unplumbif(const struct dhcpcd_ctx *ctx, int af, const char *ifname)
                errno = EAFNOSUPPORT;
                return -1;
        }
-       return if_addaddr(fd, ifname, &addr, &mask);
+       return if_addaddr(fd, ifname, &addr, &addr,
+           af == AF_INET ? &addr : NULL);
 }
 
 static int
@@ -1489,8 +1514,10 @@ bpf_send(const struct interface *ifp, __unused int fd, uint16_t protocol,
 int
 if_address(unsigned char cmd, const struct ipv4_addr *ia)
 {
-       struct sockaddr_storage ss_addr, ss_mask;
-       struct sockaddr_in      *sin_addr, *sin_mask;
+       union {
+               struct sockaddr         sa;
+               struct sockaddr_storage ss;
+       } addr, mask, brd;
 
        /* Either remove the alias or ensure it exists. */
        if (if_plumb(cmd, ia->iface->ctx, AF_INET, ia->alias) == -1)
@@ -1507,14 +1534,11 @@ if_address(unsigned char cmd, const struct ipv4_addr *ia)
        /* We need to update the index now */
        ia->iface->index = if_nametoindex(ia->alias);
 
-       sin_addr = (struct sockaddr_in *)&ss_addr;
-       sin_addr->sin_family = AF_INET;
-       sin_addr->sin_addr = ia->addr;
-       sin_mask = (struct sockaddr_in *)&ss_mask;
-       sin_mask->sin_family = AF_INET;
-       sin_mask->sin_addr = ia->mask;
-       return if_addaddr(ia->iface->ctx->pf_inet_fd,
-           ia->alias, &ss_addr, &ss_mask);
+       sa_in_init(&addr.sa, &ia->addr);
+       sa_in_init(&mask.sa, &ia->mask);
+       sa_in_init(&brd.sa, &ia->brd);
+       return if_addaddr(ia->iface->ctx->pf_inet_fd, ia->alias,
+           &addr.ss, &mask.ss, &brd.ss);
 }
 
 int
@@ -1541,9 +1565,12 @@ if_addrflags(const struct interface *ifp, const struct in_addr *addr,
 int
 if_address6(unsigned char cmd, const struct ipv6_addr *ia)
 {
-       struct sockaddr_storage ss_addr, ss_mask;
-       struct sockaddr_in6     *sin6_addr, *sin6_mask;
-       struct priv             *priv;
+       union {
+               struct sockaddr         sa;
+               struct sockaddr_in6     sin6;
+               struct sockaddr_storage ss;
+       } addr, mask;
+       const struct priv               *priv;
        int                     r;
 
        /* Either remove the alias or ensure it exists. */
@@ -1558,15 +1585,11 @@ if_address6(unsigned char cmd, const struct ipv6_addr *ia)
                return -1;
        }
 
-       priv = (struct priv *)ia->iface->ctx->priv;
-       sin6_addr = (struct sockaddr_in6 *)&ss_addr;
-       sin6_addr->sin6_family = AF_INET6;
-       sin6_addr->sin6_addr = ia->addr;
-       sin6_mask = (struct sockaddr_in6 *)&ss_mask;
-       sin6_mask->sin6_family = AF_INET6;
-       ipv6_mask(&sin6_mask->sin6_addr, ia->prefix_len);
-       r = if_addaddr(priv->pf_inet6_fd,
-           ia->alias, &ss_addr, &ss_mask);
+       sa_in6_init(&addr.sa, &ia->addr);
+       mask.sin6.sin6_family = AF_INET6;
+       ipv6_mask(&mask.sin6.sin6_addr, ia->prefix_len);
+       priv = (const struct priv *)ia->iface->ctx->priv;
+       r = if_addaddr(priv->pf_inet6_fd, ia->alias, &addr.ss, &mask.ss, NULL);
        if (r == -1 && errno == EEXIST)
                return 0;
        return r;