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https://github.com/sheumann/hush.git
synced 2024-09-12 00:55:11 +00:00
dhcp: stop using magic constants; use (htonl(CONST) != a) - it's smaller
function old new delta udhcp_get_packet 146 134 -12 get_raw_packet 368 353 -15
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@ -171,7 +171,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
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bytes = read(fd, &packet, sizeof(struct udp_dhcp_packet));
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bytes = read(fd, &packet, sizeof(struct udp_dhcp_packet));
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if (bytes < 0) {
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if (bytes < 0) {
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DEBUG("Cannot read on raw listening socket - ignoring");
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DEBUG("Cannot read on raw listening socket - ignoring");
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usleep(500000); /* possible down interface, looping condition */
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sleep(1); /* possible down interface, looping condition */
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return -1;
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return -1;
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}
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}
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@ -190,7 +190,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
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/* Make sure its the right packet for us, and that it passes sanity checks */
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/* Make sure its the right packet for us, and that it passes sanity checks */
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if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
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if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION
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|| packet.ip.ihl != sizeof(packet.ip) >> 2
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|| packet.ip.ihl != (sizeof(packet.ip) >> 2)
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|| packet.udp.dest != htons(CLIENT_PORT)
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|| packet.udp.dest != htons(CLIENT_PORT)
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|| bytes > (int) sizeof(struct udp_dhcp_packet)
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|| bytes > (int) sizeof(struct udp_dhcp_packet)
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|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
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|| ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip))
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@ -207,7 +207,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
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return -1;
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return -1;
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}
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}
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/* verify the UDP checksum by replacing the header with a psuedo header */
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/* verify the UDP checksum by replacing the header with a pseudo header */
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source = packet.ip.saddr;
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source = packet.ip.saddr;
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dest = packet.ip.daddr;
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dest = packet.ip.daddr;
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check = packet.udp.check;
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check = packet.udp.check;
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@ -225,7 +225,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd)
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memcpy(payload, &(packet.data), bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
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memcpy(payload, &(packet.data), bytes - (sizeof(packet.ip) + sizeof(packet.udp)));
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if (ntohl(payload->cookie) != DHCP_MAGIC) {
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if (payload->cookie != htonl(DHCP_MAGIC)) {
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bb_error_msg("received bogus message (bad magic) - ignoring");
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bb_error_msg("received bogus message (bad magic) - ignoring");
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return -2;
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return -2;
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}
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}
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@ -38,12 +38,18 @@ struct dhcpMessage {
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uint8_t file[128];
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uint8_t file[128];
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uint32_t cookie;
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uint32_t cookie;
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uint8_t options[308]; /* 312 - cookie */
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uint8_t options[308]; /* 312 - cookie */
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};
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} ATTRIBUTE_PACKED;
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struct udp_dhcp_packet {
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struct udp_dhcp_packet {
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struct iphdr ip;
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struct iphdr ip;
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struct udphdr udp;
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struct udphdr udp;
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struct dhcpMessage data;
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struct dhcpMessage data;
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} ATTRIBUTE_PACKED;
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/* Let's see whether compiler understood us right */
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struct BUG_bad_sizeof_struct_udp_dhcp_packet {
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char BUG_bad_sizeof_struct_udp_dhcp_packet
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[sizeof(struct udp_dhcp_packet) != 576 ? -1 : 1];
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};
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};
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void udhcp_init_header(struct dhcpMessage *packet, char type);
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void udhcp_init_header(struct dhcpMessage *packet, char type);
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@ -73,12 +73,13 @@ uint8_t *get_option(struct dhcpMessage *packet, int code)
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{
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{
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int i, length;
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int i, length;
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uint8_t *optionptr;
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uint8_t *optionptr;
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int over = 0, done = 0, curr = OPTION_FIELD;
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int over = 0;
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int curr = OPTION_FIELD;
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optionptr = packet->options;
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optionptr = packet->options;
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i = 0;
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i = 0;
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length = 308;
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length = sizeof(packet->options);
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while (!done) {
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while (1) {
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if (i >= length) {
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if (i >= length) {
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bb_error_msg("bogus packet, option fields too long");
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bb_error_msg("bogus packet, option fields too long");
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return NULL;
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return NULL;
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@ -103,17 +104,18 @@ uint8_t *get_option(struct dhcpMessage *packet, int code)
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i += optionptr[OPT_LEN] + 2;
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i += optionptr[OPT_LEN] + 2;
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break;
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break;
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case DHCP_END:
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case DHCP_END:
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if (curr == OPTION_FIELD && over & FILE_FIELD) {
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if (curr == OPTION_FIELD && (over & FILE_FIELD)) {
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optionptr = packet->file;
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optionptr = packet->file;
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i = 0;
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i = 0;
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length = 128;
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length = sizeof(packet->file);
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curr = FILE_FIELD;
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curr = FILE_FIELD;
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} else if (curr == FILE_FIELD && over & SNAME_FIELD) {
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} else if (curr == FILE_FIELD && (over & SNAME_FIELD)) {
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optionptr = packet->sname;
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optionptr = packet->sname;
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i = 0;
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i = 0;
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length = 64;
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length = sizeof(packet->sname);
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curr = SNAME_FIELD;
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curr = SNAME_FIELD;
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} else done = 1;
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} else
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return NULL;
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break;
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break;
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default:
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default:
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i += optionptr[OPT_LEN + i] + 2;
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i += optionptr[OPT_LEN + i] + 2;
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@ -6,7 +6,7 @@
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#define TYPE_MASK 0x0F
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#define TYPE_MASK 0x0F
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enum {
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enum {
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OPTION_IP=1,
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OPTION_IP = 1,
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OPTION_IP_PAIR,
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OPTION_IP_PAIR,
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OPTION_STRING,
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OPTION_STRING,
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#if ENABLE_FEATURE_RFC3397
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#if ENABLE_FEATURE_RFC3397
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@ -57,7 +57,7 @@ int udhcp_get_packet(struct dhcpMessage *packet, int fd)
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return -1;
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return -1;
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}
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}
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if (ntohl(packet->cookie) != DHCP_MAGIC) {
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if (packet->cookie != htonl(DHCP_MAGIC)) {
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bb_error_msg("received bogus message, ignoring");
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bb_error_msg("received bogus message, ignoring");
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return -2;
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return -2;
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}
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}
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@ -123,7 +123,6 @@ uint16_t udhcp_checksum(void *addr, int count)
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/* Construct a ip/udp header for a packet, and specify the source and dest hardware address */
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/* Construct a ip/udp header for a packet, and specify the source and dest hardware address */
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void BUG_sizeof_struct_udp_dhcp_packet_must_be_576(void);
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int udhcp_raw_packet(struct dhcpMessage *payload,
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int udhcp_raw_packet(struct dhcpMessage *payload,
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uint32_t source_ip, int source_port,
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uint32_t source_ip, int source_port,
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uint32_t dest_ip, int dest_port, const uint8_t *dest_arp, int ifindex)
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uint32_t dest_ip, int dest_port, const uint8_t *dest_arp, int ifindex)
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@ -169,9 +168,6 @@ int udhcp_raw_packet(struct dhcpMessage *payload,
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packet.ip.ttl = IPDEFTTL;
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packet.ip.ttl = IPDEFTTL;
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packet.ip.check = udhcp_checksum(&(packet.ip), sizeof(packet.ip));
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packet.ip.check = udhcp_checksum(&(packet.ip), sizeof(packet.ip));
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if (sizeof(struct udp_dhcp_packet) != 576)
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BUG_sizeof_struct_udp_dhcp_packet_must_be_576();
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result = sendto(fd, &packet, sizeof(struct udp_dhcp_packet), 0,
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result = sendto(fd, &packet, sizeof(struct udp_dhcp_packet), 0,
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(struct sockaddr *) &dest, sizeof(dest));
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(struct sockaddr *) &dest, sizeof(dest));
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if (result <= 0) {
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if (result <= 0) {
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