diff options
author | Andreas Baumann <mail@andreasbaumann.cc> | 2015-01-03 12:04:58 +0100 |
---|---|---|
committer | Andreas Baumann <mail@andreasbaumann.cc> | 2015-01-03 12:04:58 +0100 |
commit | 008d0be72b2f160382c6e880765e96b64a050c65 (patch) | |
tree | 36f48a98a3815a408e2ce1693dd182af90f80305 /release/src/linux/linux/net/ipv4/netfilter/ip_nat_proto_udp.c | |
parent | 611becfb8726c60cb060368541ad98191d4532f5 (diff) | |
download | tomato-008d0be72b2f160382c6e880765e96b64a050c65.tar.gz tomato-008d0be72b2f160382c6e880765e96b64a050c65.tar.bz2 |
imported original firmware WRT54GL_v4.30.11_11_US
Diffstat (limited to 'release/src/linux/linux/net/ipv4/netfilter/ip_nat_proto_udp.c')
-rw-r--r-- | release/src/linux/linux/net/ipv4/netfilter/ip_nat_proto_udp.c | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/release/src/linux/linux/net/ipv4/netfilter/ip_nat_proto_udp.c b/release/src/linux/linux/net/ipv4/netfilter/ip_nat_proto_udp.c new file mode 100644 index 00000000..05aefcd4 --- /dev/null +++ b/release/src/linux/linux/net/ipv4/netfilter/ip_nat_proto_udp.c @@ -0,0 +1,145 @@ +#include <linux/types.h> +#include <linux/init.h> +#include <linux/netfilter.h> +#include <linux/ip.h> +#include <linux/udp.h> +#include <linux/if.h> + +#include <linux/netfilter_ipv4/ip_nat.h> +#include <linux/netfilter_ipv4/ip_nat_rule.h> +#include <linux/netfilter_ipv4/ip_nat_protocol.h> + +static int +udp_in_range(const struct ip_conntrack_tuple *tuple, + enum ip_nat_manip_type maniptype, + const union ip_conntrack_manip_proto *min, + const union ip_conntrack_manip_proto *max) +{ + u_int16_t port; + + if (maniptype == IP_NAT_MANIP_SRC) + port = tuple->src.u.udp.port; + else + port = tuple->dst.u.udp.port; + + return ntohs(port) >= ntohs(min->udp.port) + && ntohs(port) <= ntohs(max->udp.port); +} + +static int +udp_unique_tuple(struct ip_conntrack_tuple *tuple, + const struct ip_nat_range *range, + enum ip_nat_manip_type maniptype, + const struct ip_conntrack *conntrack) +{ + static u_int16_t port = 0, *portptr; + unsigned int range_size, min, i; + + if (maniptype == IP_NAT_MANIP_SRC) + portptr = &tuple->src.u.udp.port; + else + portptr = &tuple->dst.u.udp.port; + + if(ntohs(*portptr) == 500) + return 0;//must not be "return 1" + + /* If no range specified... */ + if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) { + /* If it's dst rewrite, can't change port */ + if (maniptype == IP_NAT_MANIP_DST) + return 0; + + if (ntohs(*portptr) < 1024) { + /* Loose convention: >> 512 is credential passing */ + if (ntohs(*portptr)<512) { + min = 1; + range_size = 511 - min + 1; + } else { + min = 600; + range_size = 1023 - min + 1; + } + } else { + min = 1024; + range_size = 65535 - 1024 + 1; + } + } else { + min = ntohs(range->min.udp.port); + range_size = ntohs(range->max.udp.port) - min + 1; + } + + for (i = 0; i < range_size; i++, port++) { + *portptr = htons(min + port % range_size); + if (!ip_nat_used_tuple(tuple, conntrack)) + return 1; + } + return 0; +} + +static void +udp_manip_pkt(struct iphdr *iph, size_t len, + const struct ip_conntrack_manip *manip, + enum ip_nat_manip_type maniptype) +{ + struct udphdr *hdr = (struct udphdr *)((u_int32_t *)iph + iph->ihl); + u_int32_t oldip; + u_int16_t *portptr; + + if (maniptype == IP_NAT_MANIP_SRC) { + /* Get rid of src ip and src pt */ + oldip = iph->saddr; + portptr = &hdr->source; + } else { + /* Get rid of dst ip and dst pt */ + oldip = iph->daddr; + portptr = &hdr->dest; + } + if (hdr->check) /* 0 is a special case meaning no checksum */ + hdr->check = ip_nat_cheat_check(~oldip, manip->ip, + ip_nat_cheat_check(*portptr ^ 0xFFFF, + manip->u.udp.port, + hdr->check)); + *portptr = manip->u.udp.port; +} + +static unsigned int +udp_print(char *buffer, + const struct ip_conntrack_tuple *match, + const struct ip_conntrack_tuple *mask) +{ + unsigned int len = 0; + + if (mask->src.u.udp.port) + len += sprintf(buffer + len, "srcpt=%u ", + ntohs(match->src.u.udp.port)); + + + if (mask->dst.u.udp.port) + len += sprintf(buffer + len, "dstpt=%u ", + ntohs(match->dst.u.udp.port)); + + return len; +} + +static unsigned int +udp_print_range(char *buffer, const struct ip_nat_range *range) +{ + if (range->min.udp.port != 0 || range->max.udp.port != 0xFFFF) { + if (range->min.udp.port == range->max.udp.port) + return sprintf(buffer, "port %u ", + ntohs(range->min.udp.port)); + else + return sprintf(buffer, "ports %u-%u ", + ntohs(range->min.udp.port), + ntohs(range->max.udp.port)); + } + else return 0; +} + +struct ip_nat_protocol ip_nat_protocol_udp += { { NULL, NULL }, "UDP", IPPROTO_UDP, + udp_manip_pkt, + udp_in_range, + udp_unique_tuple, + udp_print, + udp_print_range +}; |