From 6884f665bd7bc101f56ff9047afaffbc06dc99e2 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Fri, 23 Nov 2007 00:08:54 +0000 Subject: 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 --- networking/udhcp/clientpacket.c | 8 ++++---- networking/udhcp/common.h | 8 +++++++- networking/udhcp/options.c | 18 ++++++++++-------- networking/udhcp/options.h | 2 +- networking/udhcp/packet.c | 6 +----- 5 files changed, 23 insertions(+), 19 deletions(-) diff --git a/networking/udhcp/clientpacket.c b/networking/udhcp/clientpacket.c index e7eeb58b1..4a5c627f4 100644 --- a/networking/udhcp/clientpacket.c +++ b/networking/udhcp/clientpacket.c @@ -171,7 +171,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd) bytes = read(fd, &packet, sizeof(struct udp_dhcp_packet)); if (bytes < 0) { DEBUG("Cannot read on raw listening socket - ignoring"); - usleep(500000); /* possible down interface, looping condition */ + sleep(1); /* possible down interface, looping condition */ return -1; } @@ -190,7 +190,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd) /* Make sure its the right packet for us, and that it passes sanity checks */ if (packet.ip.protocol != IPPROTO_UDP || packet.ip.version != IPVERSION - || packet.ip.ihl != sizeof(packet.ip) >> 2 + || packet.ip.ihl != (sizeof(packet.ip) >> 2) || packet.udp.dest != htons(CLIENT_PORT) || bytes > (int) sizeof(struct udp_dhcp_packet) || ntohs(packet.udp.len) != (uint16_t)(bytes - sizeof(packet.ip)) @@ -207,7 +207,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd) return -1; } - /* verify the UDP checksum by replacing the header with a psuedo header */ + /* verify the UDP checksum by replacing the header with a pseudo header */ source = packet.ip.saddr; dest = packet.ip.daddr; check = packet.udp.check; @@ -225,7 +225,7 @@ int get_raw_packet(struct dhcpMessage *payload, int fd) memcpy(payload, &(packet.data), bytes - (sizeof(packet.ip) + sizeof(packet.udp))); - if (ntohl(payload->cookie) != DHCP_MAGIC) { + if (payload->cookie != htonl(DHCP_MAGIC)) { bb_error_msg("received bogus message (bad magic) - ignoring"); return -2; } diff --git a/networking/udhcp/common.h b/networking/udhcp/common.h index 179c21fdb..4f2d31c98 100644 --- a/networking/udhcp/common.h +++ b/networking/udhcp/common.h @@ -38,12 +38,18 @@ struct dhcpMessage { uint8_t file[128]; uint32_t cookie; uint8_t options[308]; /* 312 - cookie */ -}; +} ATTRIBUTE_PACKED; struct udp_dhcp_packet { struct iphdr ip; struct udphdr udp; struct dhcpMessage data; +} ATTRIBUTE_PACKED; + +/* Let's see whether compiler understood us right */ +struct BUG_bad_sizeof_struct_udp_dhcp_packet { + char BUG_bad_sizeof_struct_udp_dhcp_packet + [sizeof(struct udp_dhcp_packet) != 576 ? -1 : 1]; }; void udhcp_init_header(struct dhcpMessage *packet, char type); diff --git a/networking/udhcp/options.c b/networking/udhcp/options.c index 3168fc69a..2b4f1644f 100644 --- a/networking/udhcp/options.c +++ b/networking/udhcp/options.c @@ -73,12 +73,13 @@ uint8_t *get_option(struct dhcpMessage *packet, int code) { int i, length; uint8_t *optionptr; - int over = 0, done = 0, curr = OPTION_FIELD; + int over = 0; + int curr = OPTION_FIELD; optionptr = packet->options; i = 0; - length = 308; - while (!done) { + length = sizeof(packet->options); + while (1) { if (i >= length) { bb_error_msg("bogus packet, option fields too long"); return NULL; @@ -103,17 +104,18 @@ uint8_t *get_option(struct dhcpMessage *packet, int code) i += optionptr[OPT_LEN] + 2; break; case DHCP_END: - if (curr == OPTION_FIELD && over & FILE_FIELD) { + if (curr == OPTION_FIELD && (over & FILE_FIELD)) { optionptr = packet->file; i = 0; - length = 128; + length = sizeof(packet->file); curr = FILE_FIELD; - } else if (curr == FILE_FIELD && over & SNAME_FIELD) { + } else if (curr == FILE_FIELD && (over & SNAME_FIELD)) { optionptr = packet->sname; i = 0; - length = 64; + length = sizeof(packet->sname); curr = SNAME_FIELD; - } else done = 1; + } else + return NULL; break; default: i += optionptr[OPT_LEN + i] + 2; diff --git a/networking/udhcp/options.h b/networking/udhcp/options.h index 5e9adf881..33a968ce9 100644 --- a/networking/udhcp/options.h +++ b/networking/udhcp/options.h @@ -6,7 +6,7 @@ #define TYPE_MASK 0x0F enum { - OPTION_IP=1, + OPTION_IP = 1, OPTION_IP_PAIR, OPTION_STRING, #if ENABLE_FEATURE_RFC3397 diff --git a/networking/udhcp/packet.c b/networking/udhcp/packet.c index 41cd32135..0abe851a4 100644 --- a/networking/udhcp/packet.c +++ b/networking/udhcp/packet.c @@ -57,7 +57,7 @@ int udhcp_get_packet(struct dhcpMessage *packet, int fd) return -1; } - if (ntohl(packet->cookie) != DHCP_MAGIC) { + if (packet->cookie != htonl(DHCP_MAGIC)) { bb_error_msg("received bogus message, ignoring"); return -2; } @@ -123,7 +123,6 @@ uint16_t udhcp_checksum(void *addr, int count) /* Construct a ip/udp header for a packet, and specify the source and dest hardware address */ -void BUG_sizeof_struct_udp_dhcp_packet_must_be_576(void); int udhcp_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) @@ -169,9 +168,6 @@ int udhcp_raw_packet(struct dhcpMessage *payload, packet.ip.ttl = IPDEFTTL; packet.ip.check = udhcp_checksum(&(packet.ip), sizeof(packet.ip)); - if (sizeof(struct udp_dhcp_packet) != 576) - BUG_sizeof_struct_udp_dhcp_packet_must_be_576(); - result = sendto(fd, &packet, sizeof(struct udp_dhcp_packet), 0, (struct sockaddr *) &dest, sizeof(dest)); if (result <= 0) { -- cgit v1.2.3