BSD: Use IP_RECVIF

IP_RECVIF is supported on all BSD platforms as well as Solaris,
so it's more widely available than IP_PKTINFO.

This allows us to ensure that all platforms can retrieve the
receving interface from UDP network packets and thus make the code
paths a lot easier.

diff --git a/src/dhcp.c b/src/dhcp.c
index 65c81f6d086231b53d4976a6f2b1a33c808c5561..d26636d4664656ca9ceebe0824edb6cc5c9d99c7 100644 (file)
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -41,6 +41,10 @@
 #include <netinet/udp.h>
 #undef __FAVOR_BSD
 
+#ifdef AF_LINK
+#  include <net/if_dl.h>
+#endif
+
 #include <assert.h>
 #include <ctype.h>
 #include <errno.h>
@@ -1550,7 +1554,10 @@ dhcp_openudp(struct interface *ifp)
        n = 1;
        if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &n, sizeof(n)) == -1)
                goto eexit;
-#ifdef IP_RECVPKTINFO
+#ifdef IP_RECVIF
+       if (setsockopt(s, IPPROTO_IP, IP_RECVIF, &n, sizeof(n)) == -1)
+               goto eexit;
+#else
        if (setsockopt(s, IPPROTO_IP, IP_RECVPKTINFO, &n, sizeof(n)) == -1)
                goto eexit;
 #endif
@@ -1647,39 +1654,36 @@ dhcp_makeudppacket(size_t *sz, const uint8_t *data, size_t length,
 static ssize_t
 dhcp_sendudp(struct interface *ifp, struct in_addr *to, void *data, size_t len)
 {
-       int s;
-       struct msghdr msg;
-       struct sockaddr_in sin;
-       struct iovec iov[1];
-       struct dhcp_state *state = D_STATE(ifp);
-       ssize_t r;
-
-       iov[0].iov_base = data;
-       iov[0].iov_len = len;
-
-       memset(&sin, 0, sizeof(sin));
-       sin.sin_family = AF_INET;
-       sin.sin_addr = *to;
-       sin.sin_port = htons(BOOTPS);
+       struct sockaddr_in sin = {
+               .sin_family = AF_INET,
+               .sin_addr = *to,
+               .sin_port = htons(BOOTPS),
 #ifdef HAVE_SA_LEN
-       sin.sin_len = sizeof(sin);
+               .sin_len = sizeof(sin),
 #endif
+       };
+       struct iovec iov[] = {
+               { .iov_base = data, .iov_len = len }
+       };
+       struct msghdr msg = {
+               .msg_name = (void *)&sin,
+               .msg_namelen = sizeof(sin),
+               .msg_iov = iov,
+               .msg_iovlen = 1,
+       };
+       struct dhcp_state *state = D_STATE(ifp);
+       ssize_t r;
+       int fd;
 
-       memset(&msg, 0, sizeof(msg));
-       msg.msg_name = (void *)&sin;
-       msg.msg_namelen = sizeof(sin);
-       msg.msg_iov = iov;
-       msg.msg_iovlen = 1;
-
-       s = state->udp_fd;
-       if (s == -1) {
-               s = dhcp_openudp(ifp);
-               if (s == -1)
+       fd = state->udp_fd;
+       if (fd == -1) {
+               fd = dhcp_openudp(ifp);
+               if (fd == -1)
                        return -1;
        }
-       r = sendmsg(s, &msg, 0);
+       r = sendmsg(fd, &msg, 0);
        if (state->udp_fd == -1)
-               close(s);
+               close(fd);
        return r;
 }
 
@@ -1780,7 +1784,7 @@ send_message(struct interface *ifp, uint8_t type,
         * As such we remove it from consideration without actually
         * stopping the interface. */
        if (r == -1) {
-               logerr("%s: if_sendraw", ifp->name);
+               logerr("%s: bpf_send", ifp->name);
                switch(errno) {
                case ENETDOWN:
                case ENETRESET:
@@ -2257,7 +2261,6 @@ dhcp_bind(struct interface *ifp)
 
        ipv4_applyaddr(ifp);
 
-#ifdef IP_PKTINFO
        /* Close the BPF filter as we can now receive DHCP messages
         * on a UDP socket. */
        if (state->udp_fd == -1 ||
@@ -2280,7 +2283,6 @@ dhcp_bind(struct interface *ifp)
                                    state->udp_fd, dhcp_handleifudp, ifp);
                }
        }
-#endif
 }
 
 static void
@@ -3460,16 +3462,15 @@ dhcp_readudp(struct dhcpcd_ctx *ctx, struct interface *ifp)
                .iov_base = buf,
                .iov_len = sizeof(buf),
        };
-#ifdef IP_PKTINFO
+#ifdef IP_RECVIF
+       unsigned char ctl[CMSG_SPACE(sizeof(struct sockaddr_dl))] = { 0 };
+#else
        unsigned char ctl[CMSG_SPACE(sizeof(struct in_pktinfo))] = { 0 };
-       char sfrom[INET_ADDRSTRLEN];
 #endif
        struct msghdr msg = {
            .msg_name = &from, .msg_namelen = sizeof(from),
            .msg_iov = &iov, .msg_iovlen = 1,
-#ifdef IP_PKTINFO
            .msg_control = ctl, .msg_controllen = sizeof(ctl),
-#endif
        };
        int s;
        ssize_t bytes;
@@ -3486,9 +3487,6 @@ dhcp_readudp(struct dhcpcd_ctx *ctx, struct interface *ifp)
                return;
        }
 
-#ifdef IP_PKTINFO
-       inet_ntop(AF_INET, &from.sin_addr, sfrom, sizeof(sfrom));
-
        if (ifp == NULL) {
                ifp = if_findifpfromcmsg(ctx, &msg, NULL);
                if (ifp == NULL) {
@@ -3510,7 +3508,6 @@ dhcp_readudp(struct dhcpcd_ctx *ctx, struct interface *ifp)
 
        dhcp_handlebootp(ifp, (struct bootp *)(void *)buf, (size_t)bytes,
            &from.sin_addr);
-#endif
 }
 
 static void
@@ -3521,7 +3518,6 @@ dhcp_handleudp(void *arg)
        dhcp_readudp(ctx, NULL);
 }
 
-#ifdef IP_PKTINFO
 static void
 dhcp_handleifudp(void *arg)
 {
@@ -3530,7 +3526,6 @@ dhcp_handleifudp(void *arg)
        dhcp_readudp(ifp->ctx, ifp);
 
 }
-#endif
 
 static int
 dhcp_openbpf(struct interface *ifp)

diff --git a/src/if.c b/src/if.c
index 459af3afd5ae1d6c6c0896dfe9acfe78fc5bac65..c0b67ec991442432ff3b9bd08b79d54928ed83a6 100644 (file)
--- a/src/if.c
+++ b/src/if.c
@@ -740,9 +740,13 @@ if_findifpfromcmsg(struct dhcpcd_ctx *ctx, struct msghdr *msg, int *hoplimit)
        struct cmsghdr *cm;
        unsigned int ifindex = 0;
        struct interface *ifp;
-#if defined(INET) && defined(IP_PKTINFO)
+#ifdef INET
+#ifdef IP_RECVIF
+       struct sockaddr_dl sdl;
+#else
        struct in_pktinfo ipi;
 #endif
+#endif
 #ifdef INET6
        struct in6_pktinfo ipi6;
 #else
@@ -753,15 +757,27 @@ if_findifpfromcmsg(struct dhcpcd_ctx *ctx, struct msghdr *msg, int *hoplimit)
             cm;
             cm = (struct cmsghdr *)CMSG_NXTHDR(msg, cm))
        {
-#if defined(INET) && defined(IP_PKTINFO)
+#ifdef INET
                if (cm->cmsg_level == IPPROTO_IP) {
                        switch(cm->cmsg_type) {
+#ifdef IP_RECVIF
+                       case IP_RECVIF:
+                               if (cm->cmsg_len <
+                                   offsetof(struct sockaddr_dl, sdl_index) +
+                                   sizeof(sdl.sdl_index))
+                                       continue;
+                               memcpy(&sdl, CMSG_DATA(cm),
+                                   MIN(sizeof(sdl), cm->cmsg_len));
+                               ifindex = sdl.sdl_index;
+                               break;
+#else
                        case IP_PKTINFO:
                                if (cm->cmsg_len != CMSG_LEN(sizeof(ipi)))
                                        continue;
                                memcpy(&ipi, CMSG_DATA(cm), sizeof(ipi));
                                ifindex = (unsigned int)ipi.ipi_ifindex;
                                break;
+#endif
                        }
                }
 #endif