dhcpv4: move dest handling from dhcpv4_handle_msg()

dhcpv4_handle_msg() is already over 300 lines of code, break out the
destination handling into a separate function to make the former function a bit
more manageable in size.

Signed-off-by: David Härdeman <[email protected]>
Link: https://github.com/openwrt/odhcpd/pull/278
Signed-off-by: Álvaro Fernández Rojas <[email protected]>

diff --git a/src/dhcpv4.c b/src/dhcpv4.c
index 236dbcbefdbc7290b4765f3cccac2b7e58d7afce..d1d975bda8f8d62d47c7aa0de7e50b99aea56ceb 100644 (file)
--- a/src/dhcpv4.c
+++ b/src/dhcpv4.c
@@ -556,18 +556,80 @@ static ssize_t dhcpv4_send_reply(struct iovec *iov, size_t iov_len,
        return sendmsg(*sock, &msg, MSG_DONTWAIT);
 }
 
+static void dhcpv4_set_dest_addr(const struct interface *iface,
+                                uint8_t reply_msg,
+                                const struct dhcpv4_message *req,
+                                const struct dhcpv4_message *reply,
+                                const struct sockaddr_in *src,
+                                struct sockaddr_in *dest)
+{
+       *dest = *src;
+
+       //struct sockaddr_in dest = *((struct sockaddr_in*)addr);
+       if (req->giaddr.s_addr) {
+               /*
+                * relay agent is configured, send reply to the agent
+                */
+               dest->sin_addr = req->giaddr;
+               dest->sin_port = htons(DHCPV4_SERVER_PORT);
+
+       } else if (req->ciaddr.s_addr && req->ciaddr.s_addr != dest->sin_addr.s_addr) {
+               /*
+                * client has existing configuration (ciaddr is set) AND this
+                * address is not the address it used for the dhcp message
+                */
+               dest->sin_addr = req->ciaddr;
+               dest->sin_port = htons(DHCPV4_CLIENT_PORT);
+
+       } else if (ntohs(req->flags) & DHCPV4_FLAG_BROADCAST ||
+                  req->hlen != reply->hlen || !reply->yiaddr.s_addr) {
+               /*
+                * client requests a broadcast reply OR we can't offer an IP
+                */
+               dest->sin_addr.s_addr = INADDR_BROADCAST;
+               dest->sin_port = htons(DHCPV4_CLIENT_PORT);
+
+       } else if (!req->ciaddr.s_addr && reply_msg == DHCPV4_MSG_NAK) {
+               /*
+                * client has no previous configuration -> no IP, so we need to
+                * reply with a broadcast packet
+                */
+               dest->sin_addr.s_addr = INADDR_BROADCAST;
+               dest->sin_port = htons(DHCPV4_CLIENT_PORT);
+
+       } else {
+               /*
+                * send reply to the newly allocated IP
+                */
+               dest->sin_addr = reply->yiaddr;
+               dest->sin_port = htons(DHCPV4_CLIENT_PORT);
+
+               if (!(iface->ifflags & IFF_NOARP)) {
+                       struct arpreq arp = { .arp_flags = ATF_COM };
+
+                       memcpy(arp.arp_ha.sa_data, req->chaddr, 6);
+                       memcpy(&arp.arp_pa, dest, sizeof(arp.arp_pa));
+                       memcpy(arp.arp_dev, iface->ifname, sizeof(arp.arp_dev));
+
+                       if (ioctl(iface->dhcpv4_event.uloop.fd, SIOCSARP, &arp) < 0)
+                               error("ioctl(SIOCSARP): %m");
+               }
+       }
+}
+
 enum {
        IOV_HEADER = 0,
        IOV_END,
        IOV_TOTAL
 };
 
-void dhcpv4_handle_msg(void *addr, void *data, size_t len,
-               struct interface *iface, _unused void *dest_addr,
+void dhcpv4_handle_msg(void *src_addr, void *data, size_t len,
+               struct interface *iface, _unused void *our_dest_addr,
                send_reply_cb_t send_reply, void *opaque)
 {
        struct dhcpv4_message *req = data;
        int sock = iface->dhcpv4_event.uloop.fd;
+       struct sockaddr_in dest_addr;
        struct dhcpv4_message reply = {
                .op = DHCPV4_OP_BOOTREPLY,
                .htype = req->htype,
@@ -901,67 +963,22 @@ void dhcpv4_handle_msg(void *addr, void *data, size_t len,
                }
        }
 
-       struct sockaddr_in dest = *((struct sockaddr_in*)addr);
-       if (req->giaddr.s_addr) {
-               /*
-                * relay agent is configured, send reply to the agent
-                */
-               dest.sin_addr = req->giaddr;
-               dest.sin_port = htons(DHCPV4_SERVER_PORT);
-       } else if (req->ciaddr.s_addr && req->ciaddr.s_addr != dest.sin_addr.s_addr) {
-               /*
-                * client has existing configuration (ciaddr is set) AND this address is
-                * not the address it used for the dhcp message
-                */
-               dest.sin_addr = req->ciaddr;
-               dest.sin_port = htons(DHCPV4_CLIENT_PORT);
-       } else if ((ntohs(req->flags) & DHCPV4_FLAG_BROADCAST) ||
-                       req->hlen != reply.hlen || !reply.yiaddr.s_addr) {
-               /*
-                * client requests a broadcast reply OR we can't offer an IP
-                */
-               dest.sin_addr.s_addr = INADDR_BROADCAST;
-               dest.sin_port = htons(DHCPV4_CLIENT_PORT);
-       } else if (!req->ciaddr.s_addr && msg == DHCPV4_MSG_NAK) {
-               /*
-                * client has no previous configuration -> no IP, so we need to reply
-                * with a broadcast packet
-                */
-               dest.sin_addr.s_addr = INADDR_BROADCAST;
-               dest.sin_port = htons(DHCPV4_CLIENT_PORT);
-       } else {
-               struct arpreq arp = {.arp_flags = ATF_COM};
-
-               /*
-                * send reply to the newly (in this process) allocated IP
-                */
-               dest.sin_addr = reply.yiaddr;
-               dest.sin_port = htons(DHCPV4_CLIENT_PORT);
-
-               if (!(iface->ifflags & IFF_NOARP)) {
-                       memcpy(arp.arp_ha.sa_data, req->chaddr, 6);
-                       memcpy(&arp.arp_pa, &dest, sizeof(arp.arp_pa));
-                       memcpy(arp.arp_dev, iface->ifname, sizeof(arp.arp_dev));
-
-                       if (ioctl(sock, SIOCSARP, &arp) < 0)
-                               error("ioctl(SIOCSARP): %m");
-               }
-       }
+       dhcpv4_set_dest_addr(iface, msg, req, &reply, src_addr, &dest_addr);
 
        iov[IOV_HEADER].iov_len = PACKET_SIZE(&reply, cursor);
 
-       if (send_reply(iov, ARRAY_SIZE(iov), (struct sockaddr *)&dest, sizeof(dest), opaque) < 0)
+       if (send_reply(iov, ARRAY_SIZE(iov), (struct sockaddr *)&dest_addr, sizeof(dest_addr), opaque) < 0)
                error("Failed to send %s to %s - %s: %m",
                      dhcpv4_msg_to_string(msg),
-                     dest.sin_addr.s_addr == INADDR_BROADCAST ?
+                     dest_addr.sin_addr.s_addr == INADDR_BROADCAST ?
                      "ff:ff:ff:ff:ff:ff": odhcpd_print_mac(req->chaddr, req->hlen),
-                     inet_ntoa(dest.sin_addr));
+                     inet_ntoa(dest_addr.sin_addr));
        else
-               debug("Sent %s to %s - %s",
+               error("Sent %s to %s - %s",
                      dhcpv4_msg_to_string(msg),
-                     dest.sin_addr.s_addr == INADDR_BROADCAST ?
+                     dest_addr.sin_addr.s_addr == INADDR_BROADCAST ?
                      "ff:ff:ff:ff:ff:ff": odhcpd_print_mac(req->chaddr, req->hlen),
-                     inet_ntoa(dest.sin_addr));
+                     inet_ntoa(dest_addr.sin_addr));
 
        if (msg == DHCPV4_MSG_ACK && a)
                ubus_bcast_dhcp_event("dhcp.ack", req->chaddr,