From 4aca87515a5083ae0e31ce3177189fd43b6d05ac Mon Sep 17 00:00:00 2001 From: Andreas Baumann Date: Sat, 3 Jan 2015 13:58:15 +0100 Subject: patch to Vanilla Tomato 1.28 --- .../src/router/busybox/networking/udhcp/packet.c | 269 ++++++++++++++------- 1 file changed, 183 insertions(+), 86 deletions(-) (limited to 'release/src/router/busybox/networking/udhcp/packet.c') diff --git a/release/src/router/busybox/networking/udhcp/packet.c b/release/src/router/busybox/networking/udhcp/packet.c index 0f2a3bc6..33320238 100644 --- a/release/src/router/busybox/networking/udhcp/packet.c +++ b/release/src/router/busybox/networking/udhcp/packet.c @@ -1,10 +1,13 @@ -#include -#include +/* vi: set sw=4 ts=4: */ +/* + * packet.c -- packet ops + * Rewrite by Russ Dill July 2001 + * + * Licensed under GPLv2, see file LICENSE in this tarball for details. + */ + #include -#include -#include -#include -#if __GLIBC__ >=2 && __GLIBC_MINOR >= 1 +#if (defined(__GLIBC__) && __GLIBC__ >= 2 && __GLIBC_MINOR__ >= 1) || defined _NEWLIB_VERSION #include #include #else @@ -12,27 +15,22 @@ #include #include #endif -#include +#include "common.h" #include "dhcpd.h" #include "options.h" -#include "common.h" +int minpkt = 0; // zzz -void init_header(struct dhcpMessage *packet, char type) +void FAST_FUNC udhcp_init_header(struct dhcpMessage *packet, char type) { memset(packet, 0, sizeof(struct dhcpMessage)); + packet->op = BOOTREQUEST; /* if client to a server */ switch (type) { - case DHCPDISCOVER: - case DHCPREQUEST: - case DHCPRELEASE: - case DHCPINFORM: - packet->op = BOOTREQUEST; - break; case DHCPOFFER: case DHCPACK: case DHCPNAK: - packet->op = BOOTREPLY; + packet->op = BOOTREPLY; /* if server to client */ } packet->htype = ETH_10MB; packet->hlen = ETH_10MB_LEN; @@ -43,52 +41,64 @@ void init_header(struct dhcpMessage *packet, char type) /* read a packet from socket fd, return -1 on read error, -2 on packet error */ -int get_packet(struct dhcpMessage *packet, int fd) +int FAST_FUNC udhcp_recv_kernel_packet(struct dhcpMessage *packet, int fd) { int bytes; - int i; - const char broken_vendors[][8] = { - "MSFT 98", - "" - }; - char unsigned *vendor; + unsigned char *vendor; - memset(packet, 0, sizeof(struct dhcpMessage)); - bytes = read(fd, packet, sizeof(struct dhcpMessage)); + memset(packet, 0, sizeof(*packet)); + bytes = safe_read(fd, packet, sizeof(*packet)); if (bytes < 0) { - DEBUG(LOG_INFO, "couldn't read on listening socket, ignoring"); - return -1; + DEBUG("cannot read on listening socket, ignoring"); + return bytes; /* returns -1 */ } - if (ntohl(packet->cookie) != DHCP_MAGIC) { - LOG(LOG_ERR, "received bogus message, ignoring"); + if (packet->cookie != htonl(DHCP_MAGIC)) { + bb_error_msg("received bogus message, ignoring"); return -2; } - DEBUG(LOG_INFO, "Received a packet"); - - if (packet->op == BOOTREQUEST && (vendor = get_option(packet, DHCP_VENDOR))) { - for (i = 0; broken_vendors[i][0]; i++) { - if (vendor[OPT_LEN - 2] == (unsigned char) strlen(broken_vendors[i]) && - !strncmp(vendor, broken_vendors[i], vendor[OPT_LEN - 2])) { - DEBUG(LOG_INFO, "broken client (%s), forcing broadcast", - broken_vendors[i]); - packet->flags |= htons(BROADCAST_FLAG); + DEBUG("Received a packet"); + + if (packet->op == BOOTREQUEST) { + vendor = get_option(packet, DHCP_VENDOR); + if (vendor) { +#if 0 + static const char broken_vendors[][8] = { + "MSFT 98", + "" + }; + int i; + for (i = 0; broken_vendors[i][0]; i++) { + if (vendor[OPT_LEN - 2] == (uint8_t)strlen(broken_vendors[i]) + && !strncmp((char*)vendor, broken_vendors[i], vendor[OPT_LEN - 2]) + ) { + DEBUG("broken client (%s), forcing broadcast replies", + broken_vendors[i]); + packet->flags |= htons(BROADCAST_FLAG); + } } +#else + if (vendor[OPT_LEN - 2] == (uint8_t)(sizeof("MSFT 98")-1) + && memcmp(vendor, "MSFT 98", sizeof("MSFT 98")-1) == 0 + ) { + DEBUG("broken client (%s), forcing broadcast replies", "MSFT 98"); + packet->flags |= htons(BROADCAST_FLAG); + } +#endif } } - return bytes; } -u_int16_t checksum(void *addr, int count) +uint16_t FAST_FUNC udhcp_checksum(void *addr, int count) { /* Compute Internet Checksum for "count" bytes * beginning at location "addr". */ - register int32_t sum = 0; - u_int16_t *source = (u_int16_t *) addr; + int32_t sum = 0; + uint16_t *source = (uint16_t *) addr; while (count > 1) { /* This is the inner loop */ @@ -100,8 +110,8 @@ u_int16_t checksum(void *addr, int count) if (count > 0) { /* Make sure that the left-over byte is added correctly both * with little and big endian hosts */ - u_int16_t tmp = 0; - *(unsigned char *) (&tmp) = * (unsigned char *) source; + uint16_t tmp = 0; + *(uint8_t*)&tmp = *(uint8_t*)source; sum += tmp; } /* Fold 32-bit sum to 16 bits */ @@ -112,90 +122,177 @@ u_int16_t checksum(void *addr, int count) } -/* Constuct a ip/udp header for a packet, and specify the source and dest hardware address */ -int raw_packet(struct dhcpMessage *payload, u_int32_t source_ip, int source_port, - u_int32_t dest_ip, int dest_port, unsigned char *dest_arp, int ifindex) +/* Construct a ip/udp header for a packet, send packet */ +int FAST_FUNC udhcp_send_raw_packet(struct dhcpMessage *payload, + uint32_t source_ip, int source_port, + uint32_t dest_ip, int dest_port, const uint8_t *dest_arp, + int ifindex) { - int fd; - int result; struct sockaddr_ll dest; struct udp_dhcp_packet packet; + int fd; + int result = -1; + const char *msg; + + enum { + IP_UPD_DHCP_SIZE = sizeof(struct udp_dhcp_packet) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, + UPD_DHCP_SIZE = IP_UPD_DHCP_SIZE - offsetof(struct udp_dhcp_packet, udp), + }; - if ((fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP))) < 0) { - DEBUG(LOG_ERR, "socket call failed: %m"); - return -1; + fd = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP)); + if (fd < 0) { + msg = "socket(%s)"; + goto ret_msg; } - + memset(&dest, 0, sizeof(dest)); memset(&packet, 0, sizeof(packet)); - + packet.data = *payload; /* struct copy */ + dest.sll_family = AF_PACKET; dest.sll_protocol = htons(ETH_P_IP); dest.sll_ifindex = ifindex; dest.sll_halen = 6; memcpy(dest.sll_addr, dest_arp, 6); - if (bind(fd, (struct sockaddr *)&dest, sizeof(struct sockaddr_ll)) < 0) { - DEBUG(LOG_ERR, "bind call failed: %m"); - close(fd); - return -1; + if (bind(fd, (struct sockaddr *)&dest, sizeof(dest)) < 0) { + msg = "bind(%s)"; + goto ret_close; } +#if 1 // zzz + int n; + + // n = size of dhcp only + if (minpkt) n = (end_option(payload->options) + 1 + sizeof(*payload) - sizeof(payload->options)); + else n = sizeof(struct dhcpMessage) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS; + packet.ip.protocol = IPPROTO_UDP; packet.ip.saddr = source_ip; packet.ip.daddr = dest_ip; packet.udp.source = htons(source_port); packet.udp.dest = htons(dest_port); - packet.udp.len = htons(sizeof(packet.udp) + sizeof(struct dhcpMessage)); /* cheat on the psuedo-header */ + /* size, excluding IP header: */ + packet.udp.len = htons(sizeof(packet.udp) + n); // udp + dhcp + + n += sizeof(packet) - sizeof(packet.data); // n = ip + udp + dhcp + + /* for UDP checksumming, ip.len is set to UDP packet len */ packet.ip.tot_len = packet.udp.len; - memcpy(&(packet.data), payload, sizeof(struct dhcpMessage)); - packet.udp.check = checksum(&packet, sizeof(struct udp_dhcp_packet)); - - packet.ip.tot_len = htons(sizeof(struct udp_dhcp_packet)); + packet.udp.check = udhcp_checksum(&packet, n); + /* but for sending, it is set to IP packet len */ + packet.ip.tot_len = htons(n); packet.ip.ihl = sizeof(packet.ip) >> 2; packet.ip.version = IPVERSION; packet.ip.ttl = IPDEFTTL; - packet.ip.check = checksum(&(packet.ip), sizeof(packet.ip)); + packet.ip.check = udhcp_checksum(&packet.ip, sizeof(packet.ip)); +/* + bb_info_msg("%s", __FUNCTION__); + bb_info_msg("packet.udp.len=%d", ntohs(packet.udp.len)); + bb_info_msg("packet.ip.tot_len=%d", ntohs(packet.ip.tot_len)); + bb_info_msg("UPD_DHCP_SIZE=%d", UPD_DHCP_SIZE); + bb_info_msg("IP_UPD_DHCP_SIZE=%d", IP_UPD_DHCP_SIZE); +*/ + result = sendto(fd, &packet, n, 0, (struct sockaddr *) &dest, sizeof(dest)); +#else + packet.ip.protocol = IPPROTO_UDP; + packet.ip.saddr = source_ip; + packet.ip.daddr = dest_ip; + packet.udp.source = htons(source_port); + packet.udp.dest = htons(dest_port); + /* size, excluding IP header: */ + packet.udp.len = htons(UPD_DHCP_SIZE); + /* for UDP checksumming, ip.len is set to UDP packet len */ + packet.ip.tot_len = packet.udp.len; + packet.udp.check = udhcp_checksum(&packet, IP_UPD_DHCP_SIZE); + /* but for sending, it is set to IP packet len */ + packet.ip.tot_len = htons(IP_UPD_DHCP_SIZE); + packet.ip.ihl = sizeof(packet.ip) >> 2; + packet.ip.version = IPVERSION; + packet.ip.ttl = IPDEFTTL; + packet.ip.check = udhcp_checksum(&packet.ip, sizeof(packet.ip)); - result = sendto(fd, &packet, sizeof(struct udp_dhcp_packet), 0, (struct sockaddr *) &dest, sizeof(dest)); - if (result <= 0) { - DEBUG(LOG_ERR, "write on socket failed: %m"); - } + /* Currently we send full-sized DHCP packets (zero padded). + * If you need to change this: last byte of the packet is + * packet.data.options[end_option(packet.data.options)] + */ + result = sendto(fd, &packet, IP_UPD_DHCP_SIZE, 0, + (struct sockaddr *) &dest, sizeof(dest)); +#endif + + msg = "sendto"; + ret_close: close(fd); + if (result < 0) { + ret_msg: + bb_perror_msg(msg, "PACKET"); + } return result; } /* Let the kernel do all the work for packet generation */ -int kernel_packet(struct dhcpMessage *payload, u_int32_t source_ip, int source_port, - u_int32_t dest_ip, int dest_port) +int FAST_FUNC udhcp_send_kernel_packet(struct dhcpMessage *payload, + uint32_t source_ip, int source_port, + uint32_t dest_ip, int dest_port) { - int n = 1; - int fd, result; struct sockaddr_in client; - - if ((fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) - return -1; - - if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *) &n, sizeof(n)) == -1) - return -1; + int fd; + int result = -1; + const char *msg; + + enum { + DHCP_SIZE = sizeof(struct dhcpMessage) - CONFIG_UDHCPC_SLACK_FOR_BUGGY_SERVERS, + }; + + fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (fd < 0) { + msg = "socket(%s)"; + goto ret_msg; + } + setsockopt_reuseaddr(fd); memset(&client, 0, sizeof(client)); client.sin_family = AF_INET; client.sin_port = htons(source_port); client.sin_addr.s_addr = source_ip; - - if (bind(fd, (struct sockaddr *)&client, sizeof(struct sockaddr)) == -1) - return -1; + if (bind(fd, (struct sockaddr *)&client, sizeof(client)) == -1) { + msg = "bind(%s)"; + goto ret_close; + } memset(&client, 0, sizeof(client)); client.sin_family = AF_INET; client.sin_port = htons(dest_port); - client.sin_addr.s_addr = dest_ip; + client.sin_addr.s_addr = dest_ip; + if (connect(fd, (struct sockaddr *)&client, sizeof(client)) == -1) { + msg = "connect"; + goto ret_close; + } - if (connect(fd, (struct sockaddr *)&client, sizeof(struct sockaddr)) == -1) - return -1; +#if 1 // zzz + int n; - result = write(fd, payload, sizeof(struct dhcpMessage)); + if (minpkt) n = (end_option(payload->options) + 1 + sizeof(*payload) - sizeof(payload->options)); + else n = DHCP_SIZE; +/* + bb_info_msg("%s n=%d", __FUNCTION__, n); + bb_info_msg("%s", __FUNCTION__); + bb_info_msg("n=%d", n); + bb_info_msg("DHCP_SIZE=%d", DHCP_SIZE); +*/ + result = write(fd, payload, n); + +#else + /* Currently we send full-sized DHCP packets (see above) */ + result = safe_write(fd, payload, DHCP_SIZE); +#endif + + msg = "write"; + ret_close: close(fd); + if (result < 0) { + ret_msg: + bb_perror_msg(msg, "UDP"); + } return result; -} +} -- cgit v1.2.3-54-g00ecf