udhcpc: regularize the names of receiving functions,

pause on "serious failure to receive".
Some misc fixes are also folded in here.

networking/udhcp/clientpacket.c

@@ -175,7 +175,7 @@ int send_release(uint32_t server, uint32_t ciaddr)
 
 
 /* Returns -1 on errors that are fatal for the socket, -2 for those that aren't */
-int get_raw_packet(struct dhcpMessage *payload, int fd)
+int udhcp_recv_raw_packet(struct dhcpMessage *payload, int fd)
 {
 	int bytes;
 	struct udp_dhcp_packet packet;
@@ -185,7 +185,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
 	bytes = safe_read(fd, &packet, sizeof(packet));
 	if (bytes < 0) {
 		DEBUG("Cannot read on raw listening socket - ignoring");
-		sleep(1); /* possible down interface, looping condition */
+		/* NB: possible down interface, etc. Caller should pause. */
 		return bytes; /* returns -1 */
 	}
 

networking/udhcp/common.h

@@ -61,7 +61,9 @@ uint16_t udhcp_checksum(void *addr, int count);
 
 void udhcp_init_header(struct dhcpMessage *packet, char type);
 
-int udhcp_recv_packet(struct dhcpMessage *packet, int fd);
+/*int udhcp_recv_raw_packet(struct dhcpMessage *payload, int fd); - in dhcpc.h */
+int udhcp_recv_kernel_packet(struct dhcpMessage *packet, int fd);
+
 int udhcp_send_raw_packet(struct dhcpMessage *payload,
 		uint32_t source_ip, int source_port,
 		uint32_t dest_ip, int dest_port,

networking/udhcp/dhcpc.c

@@ -147,9 +147,7 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
 	unsigned opt;
 	int max_fd;
 	int retval;
-	int len;
 	struct timeval tv;
-	struct in_addr temp_addr;
 	struct dhcpMessage packet;
 	fd_set rfds;
 
@@ -380,7 +378,6 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
 					if (packet_num == 0)
 						xid = random_xid();
 
-					/* send discover packet */
 					send_discover(xid, requested_ip); /* broadcast */
 
 					timeout = discover_timeout;
@@ -396,7 +393,7 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
 					retval = 1;
 					goto ret;
 				}
-				/* wait to try again */
+				/* wait before trying again */
 				timeout = tryagain_timeout;
 				packet_num = 0;
 				continue;
@@ -404,11 +401,12 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
 			case REQUESTING:
 				if (packet_num < discover_retries) {
 					/* send request packet */
-					if (state == RENEW_REQUESTED)
+					if (state == RENEW_REQUESTED) /* unicast */
-						send_renew(xid, server_addr, requested_ip); /* unicast */
+						send_renew(xid, server_addr, requested_ip);
-					else send_selecting(xid, server_addr, requested_ip); /* broadcast */
+					else /* broadcast */
+						send_selecting(xid, server_addr, requested_ip);
 
-					timeout = ((packet_num == 2) ? 10 : 2);
+					timeout = discover_timeout;
 					packet_num++;
 					continue;
 				}
@@ -436,7 +434,7 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
 				/* Timed out, enter rebinding state */
 				DEBUG("Entering rebinding state");
 				state = REBINDING;
-				continue;
+				/* fall right through */
 			case REBINDING:
 				/* Lease is *really* about to run out,
 				 * try to find DHCP server using broadcast */
@@ -464,23 +462,24 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
 		/* select() didn't timeout, something did happen. */
 		/* Is is a packet? */
 		if (listen_mode != LISTEN_NONE && FD_ISSET(sockfd, &rfds)) {
+			int len;
 			/* A packet is ready, read it */
 
 			if (listen_mode == LISTEN_KERNEL)
-				len = udhcp_recv_packet(&packet, sockfd);
+				len = udhcp_recv_kernel_packet(&packet, sockfd);
 			else
-				len = get_raw_packet(&packet, sockfd);
+				len = udhcp_recv_raw_packet(&packet, sockfd);
-
+			if (len == -1) { /* error is severe, reopen socket */
+				DEBUG("error on read, %s, reopening socket", strerror(errno));
+				sleep(discover_timeout); /* 3 seconds by default */
+				change_listen_mode(listen_mode); /* just close and reopen */
+			}
 			/* If this packet will turn out to be unrelated/bogus,
 			 * we will go back and wait for next one.
 			 * Be sure timeout is properly decreased. */
 			already_waited_sec += (unsigned)monotonic_sec() - timestamp_before_wait;
-
+			if (len < 0)
-			if (len == -1) { /* error is severe, reopen socket */
+				continue;
-				DEBUG("error on read, %s, reopening socket", strerror(errno));
-				change_listen_mode(listen_mode); /* just close and reopen */
-			}
-			if (len < 0) continue;
 
 			if (packet.xid != xid) {
 				DEBUG("Ignoring XID %x (our xid is %x)",
@@ -563,9 +562,12 @@ int udhcpc_main(int argc ATTRIBUTE_UNUSED, char **argv)
 #endif
 					/* enter bound state */
 					timeout = lease_seconds / 2;
+					{
+						struct in_addr temp_addr;
 						temp_addr.s_addr = packet.yiaddr;
 						bb_info_msg("Lease of %s obtained, lease time %u",
 							inet_ntoa(temp_addr), (unsigned)lease_seconds);
+					}
 					requested_ip = packet.yiaddr;
 					udhcp_run_script(&packet,
 						   ((state == RENEWING || state == REBINDING) ? "renew" : "bound"));

networking/udhcp/dhcpc.h

@@ -62,7 +62,8 @@ int send_decline(uint32_t xid, uint32_t server, uint32_t requested);
 int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr);
 int send_renew(uint32_t xid, uint32_t server, uint32_t ciaddr);
 int send_release(uint32_t server, uint32_t ciaddr);
-int get_raw_packet(struct dhcpMessage *payload, int fd);
+
+int udhcp_recv_raw_packet(struct dhcpMessage *payload, int fd);
 
 #if __GNUC_PREREQ(4,1)
 # pragma GCC visibility pop

networking/udhcp/dhcpd.c

@@ -145,7 +145,7 @@ int udhcpd_main(int argc ATTRIBUTE_UNUSED, char **argv)
 		default: continue;	/* signal or error (probably EINTR) */
 		}
 
-		bytes = udhcp_recv_packet(&packet, server_socket); /* this waits for a packet - idle */
+		bytes = udhcp_recv_kernel_packet(&packet, server_socket); /* this waits for a packet - idle */
 		if (bytes < 0) {
 			if (bytes == -1 && errno != EINTR) {
 				DEBUG("error on read, %s, reopening socket", strerror(errno));
@@ -180,7 +180,7 @@ int udhcpd_main(int argc ATTRIBUTE_UNUSED, char **argv)
 		case DHCPDISCOVER:
 			DEBUG("Received DISCOVER");
 
-			if (sendOffer(&packet) < 0) {
+			if (send_offer(&packet) < 0) {
 				bb_error_msg("send OFFER failed");
 			}
 			break;
@@ -200,20 +200,19 @@ int udhcpd_main(int argc ATTRIBUTE_UNUSED, char **argv)
 					if (server_id_align == server_config.server && requested
 					 && requested_align == lease->yiaddr
 					) {
-						sendACK(&packet, lease->yiaddr);
+						send_ACK(&packet, lease->yiaddr);
 					}
 				} else if (requested) {
 					/* INIT-REBOOT State */
 					if (lease->yiaddr == requested_align)
-						sendACK(&packet, lease->yiaddr);
+						send_ACK(&packet, lease->yiaddr);
 					else
-						sendNAK(&packet);
+						send_NAK(&packet);
 				} else if (lease->yiaddr == packet.ciaddr) {
 					/* RENEWING or REBINDING State */
-					sendACK(&packet, lease->yiaddr);
+					send_ACK(&packet, lease->yiaddr);
-				} else {
+				} else { /* don't know what to do!!!! */
-					/* don't know what to do!!!! */
+					send_NAK(&packet);
-					sendNAK(&packet);
 				}
 
 			/* what to do if we have no record of the client */
@@ -229,13 +228,13 @@ int udhcpd_main(int argc ATTRIBUTE_UNUSED, char **argv)
 						memset(lease->chaddr, 0, 16);
 					/* make some contention for this address */
 					} else
-						sendNAK(&packet);
+						send_NAK(&packet);
 				} else {
 					uint32_t r = ntohl(requested_align);
 					if (r < server_config.start_ip
 				         || r > server_config.end_ip
 					) {
-						sendNAK(&packet);
+						send_NAK(&packet);
 					}
 					/* else remain silent */
 				}

networking/udhcp/dhcpd.h

@@ -104,9 +104,9 @@ void printStaticLeases(struct static_lease **lease_struct);
 
 /*** serverpacket.h ***/
 
-int sendOffer(struct dhcpMessage *oldpacket);
+int send_offer(struct dhcpMessage *oldpacket);
-int sendNAK(struct dhcpMessage *oldpacket);
+int send_NAK(struct dhcpMessage *oldpacket);
-int sendACK(struct dhcpMessage *oldpacket, uint32_t yiaddr);
+int send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr);
 int send_inform(struct dhcpMessage *oldpacket);
 
 

networking/udhcp/dhcprelay.c

@@ -257,7 +257,7 @@ static void dhcprelay_loop(int *fds, int num_sockets, int max_socket, char **cli
 		if (select(max_socket + 1, &rfds, NULL, NULL, &tv) > 0) {
 			/* server */
 			if (FD_ISSET(fds[0], &rfds)) {
-				packlen = udhcp_recv_packet(&dhcp_msg, fds[0]);
+				packlen = udhcp_recv_kernel_packet(&dhcp_msg, fds[0]);
 				if (packlen > 0) {
 					pass_back(&dhcp_msg, packlen, fds);
 				}

networking/udhcp/packet.c

@@ -34,7 +34,7 @@ void udhcp_init_header(struct dhcpMessage *packet, char type)
 
 
 /* read a packet from socket fd, return -1 on read error, -2 on packet error */
-int udhcp_recv_packet(struct dhcpMessage *packet, int fd)
+int udhcp_recv_kernel_packet(struct dhcpMessage *packet, int fd)
 {
 	int bytes;
 	unsigned char *vendor;

networking/udhcp/serverpacket.c

@@ -67,12 +67,9 @@ static int send_packet_to_client(struct dhcpMessage *payload, int force_broadcas
 /* send a dhcp packet, if force broadcast is set, the packet will be broadcast to the client */
 static int send_packet(struct dhcpMessage *payload, int force_broadcast)
 {
-	int ret;
-
 	if (payload->giaddr)
-		ret = send_packet_to_relay(payload);
+		return send_packet_to_relay(payload);
-	else ret = send_packet_to_client(payload, force_broadcast);
+	return send_packet_to_client(payload, force_broadcast);
-	return ret;
 }
 
 
@@ -100,7 +97,7 @@ static void add_bootp_options(struct dhcpMessage *packet)
 
 
 /* send a DHCP OFFER to a DHCP DISCOVER */
-int sendOffer(struct dhcpMessage *oldpacket)
+int send_offer(struct dhcpMessage *oldpacket)
 {
 	struct dhcpMessage packet;
 	struct dhcpOfferedAddr *lease = NULL;
@@ -188,7 +185,7 @@ int sendOffer(struct dhcpMessage *oldpacket)
 }
 
 
-int sendNAK(struct dhcpMessage *oldpacket)
+int send_NAK(struct dhcpMessage *oldpacket)
 {
 	struct dhcpMessage packet;
 
@@ -199,7 +196,7 @@ int sendNAK(struct dhcpMessage *oldpacket)
 }
 
 
-int sendACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
+int send_ACK(struct dhcpMessage *oldpacket, uint32_t yiaddr)
 {
 	struct dhcpMessage packet;
 	struct option_set *curr;