diff options
-rw-r--r-- | checksum.c | 44 | ||||
-rw-r--r-- | checksum.h | 6 | ||||
-rw-r--r-- | dump.c | 8 | ||||
-rw-r--r-- | translate.c | 10 |
4 files changed, 35 insertions, 33 deletions
@@ -28,12 +28,12 @@ /* function: ip_checksum_add * adds data to a checksum - * current_sum - the current checksum (or 0 to start a new checksum) + * current - the current checksum (or 0 to start a new checksum) * data - the data to add to the checksum * len - length of data */ -uint32_t ip_checksum_add(uint32_t current_sum, const void *data, int len) { - uint32_t checksum = current_sum; +uint32_t ip_checksum_add(uint32_t current, const void *data, int len) { + uint32_t checksum = current; int left = len; const uint16_t *data_16 = data; @@ -76,38 +76,40 @@ uint16_t ip_checksum(const void *data, int len) { /* function: ipv6_pseudo_header_checksum * calculate the pseudo header checksum for use in tcp/udp/icmp headers - * current_sum - the current checksum or 0 to start a new checksum - * ip6 - the ipv6 header + * current - the current checksum or 0 to start a new checksum + * ip6 - the ipv6 header + * len - the transport length (transport header + payload) */ -uint32_t ipv6_pseudo_header_checksum(uint32_t current_sum, const struct ip6_hdr *ip6) { +uint32_t ipv6_pseudo_header_checksum(uint32_t current, const struct ip6_hdr *ip6, uint16_t len) { uint32_t checksum_len, checksum_next; - checksum_len = htonl(ntohs(ip6->ip6_plen)); + checksum_len = htonl((uint32_t) len); checksum_next = htonl(ip6->ip6_nxt); - current_sum = ip_checksum_add(current_sum,&(ip6->ip6_src),sizeof(struct in6_addr)); - current_sum = ip_checksum_add(current_sum,&(ip6->ip6_dst),sizeof(struct in6_addr)); - current_sum = ip_checksum_add(current_sum,&checksum_len,sizeof(checksum_len)); - current_sum = ip_checksum_add(current_sum,&checksum_next,sizeof(checksum_next)); + current = ip_checksum_add(current, &(ip6->ip6_src), sizeof(struct in6_addr)); + current = ip_checksum_add(current, &(ip6->ip6_dst), sizeof(struct in6_addr)); + current = ip_checksum_add(current, &checksum_len, sizeof(checksum_len)); + current = ip_checksum_add(current, &checksum_next, sizeof(checksum_next)); - return current_sum; + return current; } /* function: ipv4_pseudo_header_checksum * calculate the pseudo header checksum for use in tcp/udp headers - * current_sum - the current checksum or 0 to start a new checksum - * ip - the ipv4 header + * current - the current checksum or 0 to start a new checksum + * ip - the ipv4 header + * len - the transport length (transport header + payload) */ -uint32_t ipv4_pseudo_header_checksum(uint32_t current_sum, const struct iphdr *ip) { +uint32_t ipv4_pseudo_header_checksum(uint32_t current, const struct iphdr *ip, uint16_t len) { uint16_t temp_protocol, temp_length; temp_protocol = htons(ip->protocol); - temp_length = htons(ntohs(ip->tot_len) - ip->ihl*4); + temp_length = htons(len); - current_sum = ip_checksum_add(current_sum, &(ip->saddr), sizeof(uint32_t)); - current_sum = ip_checksum_add(current_sum, &(ip->daddr), sizeof(uint32_t)); - current_sum = ip_checksum_add(current_sum, &temp_protocol, sizeof(uint16_t)); - current_sum = ip_checksum_add(current_sum, &temp_length, sizeof(uint16_t)); + current = ip_checksum_add(current, &(ip->saddr), sizeof(uint32_t)); + current = ip_checksum_add(current, &(ip->daddr), sizeof(uint32_t)); + current = ip_checksum_add(current, &temp_protocol, sizeof(uint16_t)); + current = ip_checksum_add(current, &temp_length, sizeof(uint16_t)); - return current_sum; + return current; } @@ -18,11 +18,11 @@ #ifndef __CHECKSUM_H__ #define __CHECKSUM_H__ -uint32_t ip_checksum_add(uint32_t current_sum, const void *data, int len); +uint32_t ip_checksum_add(uint32_t current, const void *data, int len); uint16_t ip_checksum_finish(uint32_t temp_sum); uint16_t ip_checksum(const void *data, int len); -uint32_t ipv6_pseudo_header_checksum(uint32_t current_sum, const struct ip6_hdr *ip6); -uint32_t ipv4_pseudo_header_checksum(uint32_t current_sum, const struct iphdr *ip); +uint32_t ipv6_pseudo_header_checksum(uint32_t current, const struct ip6_hdr *ip6, uint16_t len); +uint32_t ipv4_pseudo_header_checksum(uint32_t current, const struct iphdr *ip, uint16_t len); #endif /* __CHECKSUM_H__ */ @@ -146,14 +146,14 @@ void dump_udp_generic(const struct udphdr *udp, uint32_t temp_checksum, const ch /* print ipv4/udp header */ void dump_udp(const struct udphdr *udp, const struct iphdr *ip, const char *payload, size_t payload_size) { uint32_t temp_checksum; - temp_checksum = ipv4_pseudo_header_checksum(0, ip); + temp_checksum = ipv4_pseudo_header_checksum(0, ip, sizeof(*udp) + payload_size); dump_udp_generic(udp, temp_checksum, payload, payload_size); } /* print ipv6/udp header */ void dump_udp6(const struct udphdr *udp, const struct ip6_hdr *ip6, const char *payload, size_t payload_size) { uint32_t temp_checksum; - temp_checksum = ipv6_pseudo_header_checksum(0, ip6); + temp_checksum = ipv6_pseudo_header_checksum(0, ip6, sizeof(*udp) + payload_size); dump_udp_generic(udp, temp_checksum, payload, payload_size); } @@ -202,7 +202,7 @@ void dump_tcp_generic(const struct tcphdr *tcp, const char *options, size_t opti void dump_tcp(const struct tcphdr *tcp, const struct iphdr *ip, const char *payload, size_t payload_size, const char *options, size_t options_size) { uint32_t temp_checksum; - temp_checksum = ipv4_pseudo_header_checksum(0, ip); + temp_checksum = ipv4_pseudo_header_checksum(0, ip, sizeof(*tcp) + options_size + payload_size); dump_tcp_generic(tcp, options, options_size, temp_checksum, payload, payload_size); } @@ -210,7 +210,7 @@ void dump_tcp(const struct tcphdr *tcp, const struct iphdr *ip, const char *payl void dump_tcp6(const struct tcphdr *tcp, const struct ip6_hdr *ip6, const char *payload, size_t payload_size, const char *options, size_t options_size) { uint32_t temp_checksum; - temp_checksum = ipv6_pseudo_header_checksum(0, ip6); + temp_checksum = ipv6_pseudo_header_checksum(0, ip6, sizeof(*tcp) + options_size + payload_size); dump_tcp_generic(tcp, options, options_size, temp_checksum, payload, payload_size); } diff --git a/translate.c b/translate.c index cdaca14..89a7e7b 100644 --- a/translate.c +++ b/translate.c @@ -142,7 +142,7 @@ void icmp_to_icmp6(int fd, const struct iphdr *ip, const struct icmphdr *icmp, c icmp6_targ.icmp6_id = icmp->un.echo.id; icmp6_targ.icmp6_seq = icmp->un.echo.sequence; - checksum_temp = ipv6_pseudo_header_checksum(0,&ip6_targ); + checksum_temp = ipv6_pseudo_header_checksum(0, &ip6_targ, sizeof(icmp6_targ) + payload_size); checksum_temp = ip_checksum_add(checksum_temp, &icmp6_targ, sizeof(icmp6_targ)); checksum_temp = ip_checksum_add(checksum_temp, payload, payload_size); icmp6_targ.icmp6_cksum = ip_checksum_finish(checksum_temp); @@ -255,7 +255,7 @@ void udp_to_udp6(int fd, const struct iphdr *ip, const struct udphdr *udp, const fill_ip6_header(&ip6_targ,payload_size + sizeof(struct udphdr),IPPROTO_UDP,ip); - checksum = ipv6_pseudo_header_checksum(0, &ip6_targ); + checksum = ipv6_pseudo_header_checksum(0, &ip6_targ, sizeof(*udp) + payload_size); io_targ[0].iov_base = &tun_header; io_targ[0].iov_len = sizeof(tun_header); @@ -283,7 +283,7 @@ void udp6_to_udp(int fd, const struct ip6_hdr *ip6, const struct udphdr *udp, co fill_ip_header(&ip_targ,payload_size + sizeof(struct udphdr),IPPROTO_UDP,ip6); - checksum = ipv4_pseudo_header_checksum(0, &ip_targ); + checksum = ipv4_pseudo_header_checksum(0, &ip_targ, sizeof(*udp) + payload_size); io_targ[0].iov_base = &tun_header; io_targ[0].iov_len = sizeof(tun_header); @@ -363,7 +363,7 @@ void tcp_to_tcp6(int fd,const struct iphdr *ip, const struct tcphdr *tcp, const fill_ip6_header(&ip6_targ,payload_size+options_size+sizeof(struct tcphdr),IPPROTO_TCP,ip); - checksum = ipv6_pseudo_header_checksum(0, &ip6_targ); + checksum = ipv6_pseudo_header_checksum(0, &ip6_targ, sizeof(*tcp) + options_size + payload_size); io_targ[0].iov_base = &tun_header; io_targ[0].iov_len = sizeof(tun_header); @@ -393,7 +393,7 @@ void tcp6_to_tcp(int fd,const struct ip6_hdr *ip6, const struct tcphdr *tcp, con fill_ip_header(&ip_targ,payload_size+options_size+sizeof(struct tcphdr),IPPROTO_TCP,ip6); - checksum = ipv4_pseudo_header_checksum(0, &ip_targ); + checksum = ipv4_pseudo_header_checksum(0, &ip_targ, sizeof(*tcp) + payload_size + options_size); io_targ[0].iov_base = &tun_header; io_targ[0].iov_len = sizeof(tun_header); |