udhcp: s/sipservers/sipsrv/ to match other similar option names
[oweals/busybox.git] / networking / udhcp / dhcprelay.c
index 08fb733d7c0bb5a174bc2cee2c0385063bc7b3ac..e14325dcaaed3e465fab07dd138a17e8fdfc662d 100644 (file)
@@ -9,11 +9,8 @@
  *                   Netbeat AG
  * Upstream has GPL v2 or later
  */
-
 #include "common.h"
-#include "options.h"
 
-/* constants */
 #define SERVER_PORT      67
 #define SELECT_TIMEOUT    5 /* select timeout in sec. */
 #define MAX_LIFETIME   2*60 /* lifetime of an xid entry in sec. */
@@ -98,7 +95,7 @@ static void xid_del(uint32_t xid)
  * p - pointer to the dhcp packet
  * returns the message type on success, -1 otherwise
  */
-static int get_dhcp_packet_type(struct dhcpMessage *p)
+static int get_dhcp_packet_type(struct dhcp_packet *p)
 {
        uint8_t *op;
 
@@ -106,7 +103,7 @@ static int get_dhcp_packet_type(struct dhcpMessage *p)
        if (p->op != BOOTREQUEST && p->op != BOOTREPLY)
                return -1;
        /* get message type option */
-       op = get_option(p, DHCP_MESSAGE_TYPE);
+       op = udhcp_get_option(p, DHCP_MESSAGE_TYPE);
        if (op != NULL)
                return op[0];
        return -1;
@@ -148,33 +145,33 @@ static char **get_client_devices(char *dev_list, int *client_number)
        return client_dev;
 }
 
-
-/* Creates listen sockets (in fds) and returns numerically max fd. */
-static int init_sockets(char **client, int num_clients,
-                       char *server, int *fds)
+/* Creates listen sockets (in fds) bound to client and server ifaces,
+ * and returns numerically max fd.
+ */
+static int init_sockets(char **client_ifaces, int num_clients,
+                       char *server_iface, int *fds)
 {
        int i, n;
 
        /* talk to real server on bootps */
-       fds[0] = listen_socket(/*INADDR_ANY,*/ SERVER_PORT, server);
+       fds[0] = udhcp_listen_socket(/*INADDR_ANY,*/ SERVER_PORT, server_iface);
        n = fds[0];
 
        for (i = 1; i < num_clients; i++) {
                /* listen for clients on bootps */
-               fds[i] = listen_socket(/*INADDR_ANY,*/ SERVER_PORT, client[i-1]);
+               fds[i] = udhcp_listen_socket(/*INADDR_ANY,*/ SERVER_PORT, client_ifaces[i-1]);
                if (fds[i] > n)
                        n = fds[i];
        }
        return n;
 }
 
-
 /**
- * pass_on() - forwards dhcp packets from client to server
+ * pass_to_server() - forwards dhcp packets from client to server
  * p - packet to send
  * client - number of the client
  */
-static void pass_on(struct dhcpMessage *p, int packet_len, int client, int *fds,
+static void pass_to_server(struct dhcp_packet *p, int packet_len, int client, int *fds,
                        struct sockaddr_in *client_addr, struct sockaddr_in *server_addr)
 {
        int res, type;
@@ -193,19 +190,19 @@ static void pass_on(struct dhcpMessage *p, int packet_len, int client, int *fds,
        item = xid_add(p->xid, client_addr, client);
 
        /* forward request to LAN (server) */
+       errno = 0;
        res = sendto(fds[0], p, packet_len, 0, (struct sockaddr*)server_addr,
                        sizeof(struct sockaddr_in));
        if (res != packet_len) {
-               bb_perror_msg("pass_on");
-               return;
+               bb_perror_msg("sendto");
        }
 }
 
 /**
- * pass_back() - forwards dhcp packets from server to client
+ * pass_to_client() - forwards dhcp packets from server to client
  * p - packet to send
  */
-static void pass_back(struct dhcpMessage *p, int packet_len, int *fds)
+static void pass_to_client(struct dhcp_packet *p, int packet_len, int *fds)
 {
        int res, type;
        struct xid_item *item;
@@ -224,10 +221,11 @@ static void pass_back(struct dhcpMessage *p, int packet_len, int *fds)
 
        if (item->ip.sin_addr.s_addr == htonl(INADDR_ANY))
                item->ip.sin_addr.s_addr = htonl(INADDR_BROADCAST);
-       res = sendto(fds[item->client], p, packet_len, 0, (struct sockaddr*)(&item->ip),
-                               sizeof(item->ip));
+       errno = 0;
+       res = sendto(fds[item->client], p, packet_len, 0, (struct sockaddr*) &(item->ip),
+                       sizeof(item->ip));
        if (res != packet_len) {
-               bb_perror_msg("pass_back");
+               bb_perror_msg("sendto");
                return;
        }
 
@@ -235,20 +233,53 @@ static void pass_back(struct dhcpMessage *p, int packet_len, int *fds)
        xid_del(p->xid);
 }
 
-static void dhcprelay_loop(int *fds, int num_sockets, int max_socket, char **clients,
-               struct sockaddr_in *server_addr, uint32_t gw_ip) ATTRIBUTE_NORETURN;
-static void dhcprelay_loop(int *fds, int num_sockets, int max_socket, char **clients,
-               struct sockaddr_in *server_addr, uint32_t gw_ip)
+int dhcprelay_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int dhcprelay_main(int argc, char **argv)
 {
-       struct dhcpMessage dhcp_msg;
-       fd_set rfds;
-       size_t packlen;
-       socklen_t addr_size;
+       struct dhcp_packet dhcp_msg;
+       struct sockaddr_in server_addr;
        struct sockaddr_in client_addr;
-       struct timeval tv;
-       int i;
+       fd_set rfds;
+       char **client_ifaces;
+       int *fds;
+       int num_sockets, max_socket;
+       uint32_t our_nip;
+
+       server_addr.sin_family = AF_INET;
+       server_addr.sin_port = htons(SERVER_PORT);
 
+       /* dhcprelay client_iface1,client_iface2,... server_iface [server_IP] */
+       if (argc == 4) {
+               if (!inet_aton(argv[3], &server_addr.sin_addr))
+                       bb_perror_msg_and_die("bad server IP");
+       } else if (argc == 3) {
+               server_addr.sin_addr.s_addr = htonl(INADDR_BROADCAST);
+       } else {
+               bb_show_usage();
+       }
+
+       /* Produce list of client ifaces */
+       client_ifaces = get_client_devices(argv[1], &num_sockets);
+
+       num_sockets++; /* for server socket at fds[0] */
+       fds = xmalloc(num_sockets * sizeof(fds[0]));
+
+       /* Create sockets and bind one to every iface */
+       max_socket = init_sockets(client_ifaces, num_sockets, argv[2], fds);
+
+       /* Get our IP on server_iface */
+       if (udhcp_read_interface(argv[2], NULL, &our_nip, NULL))
+               return 1;
+
+       /* Main loop */
        while (1) {
+//reinit stuff from time to time? go back to get_client_devices
+//every N minutes?
+               struct timeval tv;
+               size_t packlen;
+               socklen_t addr_size;
+               int i;
+
                FD_ZERO(&rfds);
                for (i = 0; i < num_sockets; i++)
                        FD_SET(fds[i], &rfds);
@@ -259,56 +290,32 @@ static void dhcprelay_loop(int *fds, int num_sockets, int max_socket, char **cli
                        if (FD_ISSET(fds[0], &rfds)) {
                                packlen = udhcp_recv_kernel_packet(&dhcp_msg, fds[0]);
                                if (packlen > 0) {
-                                       pass_back(&dhcp_msg, packlen, fds);
+                                       pass_to_client(&dhcp_msg, packlen, fds);
                                }
                        }
+                       /* clients */
                        for (i = 1; i < num_sockets; i++) {
-                               /* clients */
                                if (!FD_ISSET(fds[i], &rfds))
                                        continue;
                                addr_size = sizeof(struct sockaddr_in);
                                packlen = recvfrom(fds[i], &dhcp_msg, sizeof(dhcp_msg), 0,
-                                                       (struct sockaddr *)(&client_addr), &addr_size);
+                                               (struct sockaddr *)(&client_addr), &addr_size);
                                if (packlen <= 0)
                                        continue;
-                               if (read_interface(clients[i-1], NULL, &dhcp_msg.giaddr, NULL))
-                                       dhcp_msg.giaddr = gw_ip;
-                               pass_on(&dhcp_msg, packlen, i, fds, &client_addr, server_addr);
+
+                               /* Get our IP on corresponding client_iface */
+//why? what if server can't route such IP?
+                               if (udhcp_read_interface(client_ifaces[i-1], NULL, &dhcp_msg.gateway_nip, NULL)) {
+                                       /* Fall back to our server_iface's IP */
+//this makes more sense!
+                                       dhcp_msg.gateway_nip = our_nip;
+                               }
+//maybe set dhcp_msg.flags |= BROADCAST_FLAG too?
+                               pass_to_server(&dhcp_msg, packlen, i, fds, &client_addr, &server_addr);
                        }
                }
                xid_expire();
-       }
-}
-
-int dhcprelay_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int dhcprelay_main(int argc, char **argv)
-{
-       int num_sockets, max_socket;
-       int *fds;
-       uint32_t gw_ip;
-       char **clients;
-       struct sockaddr_in server_addr;
-
-       server_addr.sin_family = AF_INET;
-       server_addr.sin_port = htons(SERVER_PORT);
-       if (argc == 4) {
-               if (!inet_aton(argv[3], &server_addr.sin_addr))
-                       bb_perror_msg_and_die("didn't grok server");
-       } else if (argc == 3) {
-               server_addr.sin_addr.s_addr = htonl(INADDR_BROADCAST);
-       } else {
-               bb_show_usage();
-       }
-
-       clients = get_client_devices(argv[1], &num_sockets);
-       num_sockets++; /* for server socket at fds[0] */
-       fds = xmalloc(num_sockets * sizeof(fds[0]));
-       max_socket = init_sockets(clients, num_sockets, argv[2], fds);
-
-       if (read_interface(argv[2], NULL, &gw_ip, NULL))
-               return 1;
+       } /* while (1) */
 
-       /* doesn't return */
-       dhcprelay_loop(fds, num_sockets, max_socket, clients, &server_addr, gw_ip);
        /* return 0; - not reached */
 }