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authorAl Viro <viro@zeniv.linux.org.uk>2006-11-20 21:06:59 -0500
committerDavid S. Miller <davem@sunset.davemloft.net>2006-12-03 00:27:17 -0500
commit5b14027bf2132c0631ea9f3be11ced89a5057220 (patch)
treea4d28e0ca2342b8f3c85f702f483a88496c85a3a
parent8e5200f54062b8af0ed1d186ea0f113854786d89 (diff)
[NETFILTER]: ip_nat_snmp_basic annotations.
... and switch the damn checksum update to something saner Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv4/netfilter/ip_nat_snmp_basic.c85
1 files changed, 34 insertions, 51 deletions
diff --git a/net/ipv4/netfilter/ip_nat_snmp_basic.c b/net/ipv4/netfilter/ip_nat_snmp_basic.c
index 168f45fa1898..c3d9f3b090c4 100644
--- a/net/ipv4/netfilter/ip_nat_snmp_basic.c
+++ b/net/ipv4/netfilter/ip_nat_snmp_basic.c
@@ -64,7 +64,7 @@ MODULE_DESCRIPTION("Basic SNMP Application Layer Gateway");
64 64
65#define SNMP_PORT 161 65#define SNMP_PORT 161
66#define SNMP_TRAP_PORT 162 66#define SNMP_TRAP_PORT 162
67#define NOCT1(n) (u_int8_t )((n) & 0xff) 67#define NOCT1(n) (*(u8 *)n)
68 68
69static int debug; 69static int debug;
70static DEFINE_SPINLOCK(snmp_lock); 70static DEFINE_SPINLOCK(snmp_lock);
@@ -613,7 +613,7 @@ struct snmp_v1_trap
613static inline void mangle_address(unsigned char *begin, 613static inline void mangle_address(unsigned char *begin,
614 unsigned char *addr, 614 unsigned char *addr,
615 const struct oct1_map *map, 615 const struct oct1_map *map,
616 u_int16_t *check); 616 __sum16 *check);
617struct snmp_cnv 617struct snmp_cnv
618{ 618{
619 unsigned int class; 619 unsigned int class;
@@ -873,38 +873,24 @@ static unsigned char snmp_request_decode(struct asn1_ctx *ctx,
873 * Fast checksum update for possibly oddly-aligned UDP byte, from the 873 * Fast checksum update for possibly oddly-aligned UDP byte, from the
874 * code example in the draft. 874 * code example in the draft.
875 */ 875 */
876static void fast_csum(unsigned char *csum, 876static void fast_csum(__sum16 *csum,
877 const unsigned char *optr, 877 const unsigned char *optr,
878 const unsigned char *nptr, 878 const unsigned char *nptr,
879 int odd) 879 int offset)
880{ 880{
881 long x, old, new; 881 unsigned char s[4];
882 882
883 x = csum[0] * 256 + csum[1]; 883 if (offset & 1) {
884 884 s[0] = s[2] = 0;
885 x =~ x & 0xFFFF; 885 s[1] = ~*optr;
886 886 s[3] = *nptr;
887 if (odd) old = optr[0] * 256; 887 } else {
888 else old = optr[0]; 888 s[1] = s[3] = 0;
889 889 s[0] = ~*optr;
890 x -= old & 0xFFFF; 890 s[2] = *nptr;
891 if (x <= 0) {
892 x--;
893 x &= 0xFFFF;
894 }
895
896 if (odd) new = nptr[0] * 256;
897 else new = nptr[0];
898
899 x += new & 0xFFFF;
900 if (x & 0x10000) {
901 x++;
902 x &= 0xFFFF;
903 } 891 }
904 892
905 x =~ x & 0xFFFF; 893 *csum = csum_fold(csum_partial(s, 4, ~csum_unfold(*csum)));
906 csum[0] = x / 256;
907 csum[1] = x & 0xFF;
908} 894}
909 895
910/* 896/*
@@ -915,9 +901,9 @@ static void fast_csum(unsigned char *csum,
915static inline void mangle_address(unsigned char *begin, 901static inline void mangle_address(unsigned char *begin,
916 unsigned char *addr, 902 unsigned char *addr,
917 const struct oct1_map *map, 903 const struct oct1_map *map,
918 u_int16_t *check) 904 __sum16 *check)
919{ 905{
920 if (map->from == NOCT1(*addr)) { 906 if (map->from == NOCT1(addr)) {
921 u_int32_t old; 907 u_int32_t old;
922 908
923 if (debug) 909 if (debug)
@@ -927,11 +913,8 @@ static inline void mangle_address(unsigned char *begin,
927 913
928 /* Update UDP checksum if being used */ 914 /* Update UDP checksum if being used */
929 if (*check) { 915 if (*check) {
930 unsigned char odd = !((addr - begin) % 2); 916 fast_csum(check,
931 917 &map->from, &map->to, addr - begin);
932 fast_csum((unsigned char *)check,
933 &map->from, &map->to, odd);
934
935 } 918 }
936 919
937 if (debug) 920 if (debug)
@@ -943,7 +926,7 @@ static inline void mangle_address(unsigned char *begin,
943static unsigned char snmp_trap_decode(struct asn1_ctx *ctx, 926static unsigned char snmp_trap_decode(struct asn1_ctx *ctx,
944 struct snmp_v1_trap *trap, 927 struct snmp_v1_trap *trap,
945 const struct oct1_map *map, 928 const struct oct1_map *map,
946 u_int16_t *check) 929 __sum16 *check)
947{ 930{
948 unsigned int cls, con, tag, len; 931 unsigned int cls, con, tag, len;
949 unsigned char *end; 932 unsigned char *end;
@@ -1037,7 +1020,7 @@ static void hex_dump(unsigned char *buf, size_t len)
1037static int snmp_parse_mangle(unsigned char *msg, 1020static int snmp_parse_mangle(unsigned char *msg,
1038 u_int16_t len, 1021 u_int16_t len,
1039 const struct oct1_map *map, 1022 const struct oct1_map *map,
1040 u_int16_t *check) 1023 __sum16 *check)
1041{ 1024{
1042 unsigned char *eoc, *end; 1025 unsigned char *eoc, *end;
1043 unsigned int cls, con, tag, vers, pdutype; 1026 unsigned int cls, con, tag, vers, pdutype;
@@ -1223,12 +1206,12 @@ static int snmp_translate(struct ip_conntrack *ct,
1223 */ 1206 */
1224 if (dir == IP_CT_DIR_ORIGINAL) { 1207 if (dir == IP_CT_DIR_ORIGINAL) {
1225 /* SNAT traps */ 1208 /* SNAT traps */
1226 map.from = NOCT1(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip); 1209 map.from = NOCT1(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip);
1227 map.to = NOCT1(ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip); 1210 map.to = NOCT1(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip);
1228 } else { 1211 } else {
1229 /* DNAT replies */ 1212 /* DNAT replies */
1230 map.from = NOCT1(ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip); 1213 map.from = NOCT1(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip);
1231 map.to = NOCT1(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip); 1214 map.to = NOCT1(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip);
1232 } 1215 }
1233 1216
1234 if (map.from == map.to) 1217 if (map.from == map.to)
@@ -1294,11 +1277,11 @@ static struct ip_conntrack_helper snmp_helper = {
1294 .help = help, 1277 .help = help,
1295 .name = "snmp", 1278 .name = "snmp",
1296 1279
1297 .tuple = { .src = { .u = { __constant_htons(SNMP_PORT) } }, 1280 .tuple = {.src = {.u = {.udp = {.port = __constant_htons(SNMP_PORT)}}},
1298 .dst = { .protonum = IPPROTO_UDP }, 1281 .dst = {.protonum = IPPROTO_UDP},
1299 }, 1282 },
1300 .mask = { .src = { .u = { 0xFFFF } }, 1283 .mask = {.src = {.u = {0xFFFF}},
1301 .dst = { .protonum = 0xFF }, 1284 .dst = {.protonum = 0xFF},
1302 }, 1285 },
1303}; 1286};
1304 1287
@@ -1309,11 +1292,11 @@ static struct ip_conntrack_helper snmp_trap_helper = {
1309 .help = help, 1292 .help = help,
1310 .name = "snmp_trap", 1293 .name = "snmp_trap",
1311 1294
1312 .tuple = { .src = { .u = { __constant_htons(SNMP_TRAP_PORT) } }, 1295 .tuple = {.src = {.u = {.udp = {.port = __constant_htons(SNMP_TRAP_PORT)}}},
1313 .dst = { .protonum = IPPROTO_UDP }, 1296 .dst = {.protonum = IPPROTO_UDP},
1314 }, 1297 },
1315 .mask = { .src = { .u = { 0xFFFF } }, 1298 .mask = {.src = {.u = {0xFFFF}},
1316 .dst = { .protonum = 0xFF }, 1299 .dst = {.protonum = 0xFF},
1317 }, 1300 },
1318}; 1301};
1319 1302