networking: consolidate the IP checksum code. -129 bytes.
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—
(log yok)
| @@ -640,6 +640,7 @@ ssize_t recv_from_to(int fd, void *buf, size_t len, int flags, | |
| struct sockaddr *to, | |
| socklen_t sa_size) FAST_FUNC; | |
| + | uint16_t inet_cksum(uint16_t *addr, int len) FAST_FUNC; |
| char *xstrdup(const char *s) FAST_FUNC RETURNS_MALLOC; | |
| char *xstrndup(const char *s, int n) FAST_FUNC RETURNS_MALLOC; | |
| @@ -166,6 +166,12 @@ lib-$(CONFIG_IOSTAT) += get_cpu_count.o | |
| lib-$(CONFIG_MPSTAT) += get_cpu_count.o | |
| lib-$(CONFIG_POWERTOP) += get_cpu_count.o | |
| + | lib-$(CONFIG_PING) += inet_cksum.o |
| + | lib-$(CONFIG_TRACEROUTE) += inet_cksum.o |
| + | lib-$(CONFIG_TRACEROUTE6) += inet_cksum.o |
| + | lib-$(CONFIG_UDHCPC) += inet_cksum.o |
| + | lib-$(CONFIG_UDHCPD) += inet_cksum.o |
| + | |
| # We shouldn't build xregcomp.c if we don't need it - this ensures we don't | |
| # require regex.h to be in the include dir even if we don't need it thereby | |
| # allowing us to build busybox even if uclibc regex support is disabled. | |
| @@ -0,0 +1,32 @@ | |
| + | /* |
| + | * Checksum routine for Internet Protocol family headers (C Version) |
| + | * |
| + | * Licensed under GPLv2, see file LICENSE in this source tree. |
| + | */ |
| + | |
| + | #include "libbb.h" |
| + | |
| + | uint16_t FAST_FUNC inet_cksum(uint16_t *addr, int nleft) |
| + | { |
| + | /* |
| + | * Our algorithm is simple, using a 32 bit accumulator, |
| + | * we add sequential 16 bit words to it, and at the end, fold |
| + | * back all the carry bits from the top 16 bits into the lower |
| + | * 16 bits. |
| + | */ |
| + | unsigned sum = 0; |
| + | while (nleft > 1) { |
| + | sum += *addr++; |
| + | nleft -= 2; |
| + | } |
| + | |
| + | /* Mop up an odd byte, if necessary */ |
| + | if (nleft) |
| + | sum += *(uint8_t*)addr; |
| + | |
| + | /* Add back carry outs from top 16 bits to low 16 bits */ |
| + | sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ |
| + | sum += (sum >> 16); /* add carry */ |
| + | |
| + | return (uint16_t)~sum; |
| + | } |
| @@ -149,31 +149,6 @@ enum { | |
| PINGINTERVAL = 1, /* 1 second */ | |
| }; | |
| - | /* Common routines */ |
| - | |
| - | static int in_cksum(unsigned short *buf, int sz) |
| - | { |
| - | int nleft = sz; |
| - | int sum = 0; |
| - | unsigned short *w = buf; |
| - | unsigned short ans = 0; |
| - | |
| - | while (nleft > 1) { |
| - | sum += *w++; |
| - | nleft -= 2; |
| - | } |
| - | |
| - | if (nleft == 1) { |
| - | *(unsigned char *) (&ans) = *(unsigned char *) w; |
| - | sum += ans; |
| - | } |
| - | |
| - | sum = (sum >> 16) + (sum & 0xFFFF); |
| - | sum += (sum >> 16); |
| - | ans = ~sum; |
| - | return ans; |
| - | } |
| - | |
| #if !ENABLE_FEATURE_FANCY_PING | |
| /* Simple version */ | |
| @@ -201,7 +176,7 @@ static void ping4(len_and_sockaddr *lsa) | |
| pkt = (struct icmp *) G.packet; | |
| memset(pkt, 0, sizeof(G.packet)); | |
| pkt->icmp_type = ICMP_ECHO; | |
| - | pkt->icmp_cksum = in_cksum((unsigned short *) pkt, sizeof(G.packet)); |
| + | pkt->icmp_cksum = inet_cksum((uint16_t *) pkt, sizeof(G.packet)); |
| xsendto(pingsock, G.packet, DEFDATALEN + ICMP_MINLEN, &lsa->u.sa, lsa->len); | |
| @@ -493,7 +468,7 @@ static void sendping4(int junk UNUSED_PARAM) | |
| /* No hton: we'll read it back on the same machine */ | |
| *(uint32_t*)&pkt->icmp_dun = monotonic_us(); | |
| - | pkt->icmp_cksum = in_cksum((unsigned short *) pkt, datalen + ICMP_MINLEN); |
| + | pkt->icmp_cksum = inet_cksum((uint16_t *) pkt, datalen + ICMP_MINLEN); |
| sendping_tail(sendping4, ICMP_MINLEN); | |
| } | |
| @@ -512,7 +487,7 @@ static void sendping6(int junk UNUSED_PARAM) | |
| /*if (datalen >= 4)*/ | |
| *(uint32_t*)(&pkt->icmp6_data8[4]) = monotonic_us(); | |
| - | //TODO? pkt->icmp_cksum = in_cksum(...); |
| + | //TODO? pkt->icmp_cksum = inet_cksum(...); |
| sendping_tail(sendping6, sizeof(struct icmp6_hdr)); | |
| } | |
| @@ -418,39 +418,6 @@ wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timest | |
| return read_len; | |
| } | |
| - | /* |
| - | * Checksum routine for Internet Protocol family headers (C Version) |
| - | */ |
| - | static uint16_t |
| - | in_cksum(uint16_t *addr, int len) |
| - | { |
| - | int nleft = len; |
| - | uint16_t *w = addr; |
| - | uint16_t answer; |
| - | int sum = 0; |
| - | |
| - | /* |
| - | * Our algorithm is simple, using a 32 bit accumulator (sum), |
| - | * we add sequential 16 bit words to it, and at the end, fold |
| - | * back all the carry bits from the top 16 bits into the lower |
| - | * 16 bits. |
| - | */ |
| - | while (nleft > 1) { |
| - | sum += *w++; |
| - | nleft -= 2; |
| - | } |
| - | |
| - | /* mop up an odd byte, if necessary */ |
| - | if (nleft == 1) |
| - | sum += *(unsigned char *)w; |
| - | |
| - | /* add back carry outs from top 16 bits to low 16 bits */ |
| - | sum = (sum >> 16) + (sum & 0xffff); /* add hi 16 to low 16 */ |
| - | sum += (sum >> 16); /* add carry */ |
| - | answer = ~sum; /* truncate to 16 bits */ |
| - | return answer; |
| - | } |
| - | |
| static void | |
| send_probe(int seq, int ttl) | |
| { | |
| @@ -477,7 +444,7 @@ send_probe(int seq, int ttl) | |
| /* Always calculate checksum for icmp packets */ | |
| outicmp->icmp_cksum = 0; | |
| - | outicmp->icmp_cksum = in_cksum((uint16_t *)outicmp, |
| + | outicmp->icmp_cksum = inet_cksum((uint16_t *)outicmp, |
| packlen - (sizeof(*outip) + optlen)); | |
| if (outicmp->icmp_cksum == 0) | |
| outicmp->icmp_cksum = 0xffff; | |
| @@ -739,7 +739,7 @@ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) | |
| /* verify IP checksum */ | |
| check = packet.ip.check; | |
| packet.ip.check = 0; | |
| - | if (check != udhcp_checksum(&packet.ip, sizeof(packet.ip))) { |
| + | if (check != inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip))) { |
| log1("Bad IP header checksum, ignoring"); | |
| return -2; | |
| } | |
| @@ -750,7 +750,7 @@ static NOINLINE int udhcp_recv_raw_packet(struct dhcp_packet *dhcp_pkt, int fd) | |
| packet.ip.tot_len = packet.udp.len; /* yes, this is needed */ | |
| check = packet.udp.check; | |
| packet.udp.check = 0; | |
| - | if (check && check != udhcp_checksum(&packet, bytes)) { |
| + | if (check && check != inet_cksum((uint16_t *)&packet, bytes)) { |
| log1("Packet with bad UDP checksum received, ignoring"); | |
| return -2; | |
| } | |
| @@ -129,35 +129,6 @@ int FAST_FUNC udhcp_recv_kernel_packet(struct dhcp_packet *packet, int fd) | |
| return bytes; | |
| } | |
| - | uint16_t FAST_FUNC udhcp_checksum(void *addr, int count) |
| - | { |
| - | /* Compute Internet Checksum for "count" bytes |
| - | * beginning at location "addr". |
| - | */ |
| - | int32_t sum = 0; |
| - | uint16_t *source = (uint16_t *) addr; |
| - | |
| - | while (count > 1) { |
| - | /* This is the inner loop */ |
| - | sum += *source++; |
| - | count -= 2; |
| - | } |
| - | |
| - | /* Add left-over byte, if any */ |
| - | if (count > 0) { |
| - | /* Make sure that the left-over byte is added correctly both |
| - | * with little and big endian hosts */ |
| - | uint16_t tmp = 0; |
| - | *(uint8_t*)&tmp = *(uint8_t*)source; |
| - | sum += tmp; |
| - | } |
| - | /* Fold 32-bit sum to 16 bits */ |
| - | while (sum >> 16) |
| - | sum = (sum & 0xffff) + (sum >> 16); |
| - | |
| - | return ~sum; |
| - | } |
| - | |
| /* Construct a ip/udp header for a packet, send packet */ | |
| int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, | |
| uint32_t source_nip, int source_port, | |
| @@ -212,13 +183,14 @@ int FAST_FUNC udhcp_send_raw_packet(struct dhcp_packet *dhcp_pkt, | |
| packet.udp.len = htons(UDP_DHCP_SIZE - padding); | |
| /* 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_UDP_DHCP_SIZE - padding); |
| + | packet.udp.check = inet_cksum((uint16_t *)&packet, |
| + | IP_UDP_DHCP_SIZE - padding); |
| /* but for sending, it is set to IP packet len */ | |
| packet.ip.tot_len = htons(IP_UDP_DHCP_SIZE - padding); | |
| 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)); |
| + | packet.ip.check = inet_cksum((uint16_t *)&packet.ip, sizeof(packet.ip)); |
| udhcp_dump_packet(dhcp_pkt); | |
| result = sendto(fd, &packet, IP_UDP_DHCP_SIZE - padding, /*flags:*/ 0, | |