X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fpackets.c;h=eaf3e43f4c1cb86d5bbe1f10cfbc7135b9674ecd;hb=05e547e7ee479fa2c3ca5bc9d2eb57bc8a07bdb8;hp=b704276caae43dfa3eab59b69127025046c011f3;hpb=6ca00f6f1789a510bc4dbb73386a8dae197531df;p=sliver-openvswitch.git diff --git a/lib/packets.c b/lib/packets.c index b704276ca..eaf3e43f4 100644 --- a/lib/packets.c +++ b/lib/packets.c @@ -22,6 +22,7 @@ #include #include #include "byte-order.h" +#include "csum.h" #include "dynamic-string.h" #include "ofpbuf.h" @@ -77,7 +78,7 @@ compose_benign_packet(struct ofpbuf *b, const char *tag, uint16_t snap_type, } /* Insert VLAN header according to given TCI. Packet passed must be Ethernet - * packet. + * packet. Ignores the CFI bit of 'tci' using 0 instead. * * Also sets 'packet->l2' to point to the new Ethernet header. */ void @@ -91,7 +92,7 @@ eth_push_vlan(struct ofpbuf *packet, ovs_be16 tci) memcpy(tmp.veth_dst, eh->eth_dst, ETH_ADDR_LEN); memcpy(tmp.veth_src, eh->eth_src, ETH_ADDR_LEN); tmp.veth_type = htons(ETH_TYPE_VLAN); - tmp.veth_tci = tci; + tmp.veth_tci = tci & htons(~VLAN_CFI); tmp.veth_next_type = eh->eth_type; veh = ofpbuf_push_uninit(packet, VLAN_HEADER_LEN); @@ -100,6 +101,52 @@ eth_push_vlan(struct ofpbuf *packet, ovs_be16 tci) packet->l2 = packet->data; } +/* Removes outermost VLAN header (if any is present) from 'packet'. + * + * 'packet->l2' must initially point to 'packet''s Ethernet header. */ +void +eth_pop_vlan(struct ofpbuf *packet) +{ + struct vlan_eth_header *veh = packet->l2; + if (packet->size >= sizeof *veh + && veh->veth_type == htons(ETH_TYPE_VLAN)) { + struct eth_header tmp; + + memcpy(tmp.eth_dst, veh->veth_dst, ETH_ADDR_LEN); + memcpy(tmp.eth_src, veh->veth_src, ETH_ADDR_LEN); + tmp.eth_type = veh->veth_next_type; + + ofpbuf_pull(packet, VLAN_HEADER_LEN); + packet->l2 = (char*)packet->l2 + VLAN_HEADER_LEN; + memcpy(packet->data, &tmp, sizeof tmp); + } +} + +/* Converts hex digits in 'hex' to an Ethernet packet in '*packetp'. The + * caller must free '*packetp'. On success, returns NULL. On failure, returns + * an error message and stores NULL in '*packetp'. */ +const char * +eth_from_hex(const char *hex, struct ofpbuf **packetp) +{ + struct ofpbuf *packet; + + packet = *packetp = ofpbuf_new(strlen(hex) / 2); + + if (ofpbuf_put_hex(packet, hex, NULL)[0] != '\0') { + ofpbuf_delete(packet); + *packetp = NULL; + return "Trailing garbage in packet data"; + } + + if (packet->size < ETH_HEADER_LEN) { + ofpbuf_delete(packet); + *packetp = NULL; + return "Packet data too short for Ethernet"; + } + + return NULL; +} + /* Given the IP netmask 'netmask', returns the number of bits of the IP address * that it specifies, that is, the number of 1-bits in 'netmask'. 'netmask' * must be a CIDR netmask (see ip_is_cidr()). */ @@ -259,7 +306,8 @@ ipv6_is_cidr(const struct in6_addr *netmask) /* Populates 'b' with an Ethernet II packet headed with the given 'eth_dst', * 'eth_src' and 'eth_type' parameters. A payload of 'size' bytes is allocated * in 'b' and returned. This payload may be populated with appropriate - * information by the caller. + * information by the caller. Sets 'b''s 'l2' and 'l3' pointers to the + * Ethernet header and payload respectively. * * The returned packet has enough headroom to insert an 802.1Q VLAN header if * desired. */ @@ -282,6 +330,9 @@ eth_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN], memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN); eth->eth_type = htons(eth_type); + b->l2 = eth; + b->l3 = data; + return data; } @@ -327,3 +378,103 @@ snap_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN], return payload; } + +static void +packet_set_ipv4_addr(struct ofpbuf *packet, ovs_be32 *addr, ovs_be32 new_addr) +{ + struct ip_header *nh = packet->l3; + + if (nh->ip_proto == IPPROTO_TCP && packet->l7) { + struct tcp_header *th = packet->l4; + + th->tcp_csum = recalc_csum32(th->tcp_csum, *addr, new_addr); + } else if (nh->ip_proto == IPPROTO_UDP && packet->l7) { + struct udp_header *uh = packet->l4; + + if (uh->udp_csum) { + uh->udp_csum = recalc_csum32(uh->udp_csum, *addr, new_addr); + if (!uh->udp_csum) { + uh->udp_csum = htons(0xffff); + } + } + } + nh->ip_csum = recalc_csum32(nh->ip_csum, *addr, new_addr); + *addr = new_addr; +} + +/* Modifies the IPv4 header fields of 'packet' to be consistent with 'src', + * 'dst', 'tos', and 'ttl'. Updates 'packet''s L4 checksums as appropriate. + * 'packet' must contain a valid IPv4 packet with correctly populated l[347] + * markers. */ +void +packet_set_ipv4(struct ofpbuf *packet, ovs_be32 src, ovs_be32 dst, + uint8_t tos, uint8_t ttl) +{ + struct ip_header *nh = packet->l3; + + if (nh->ip_src != src) { + packet_set_ipv4_addr(packet, &nh->ip_src, src); + } + + if (nh->ip_dst != dst) { + packet_set_ipv4_addr(packet, &nh->ip_dst, dst); + } + + if (nh->ip_tos != tos) { + uint8_t *field = &nh->ip_tos; + + nh->ip_csum = recalc_csum16(nh->ip_csum, htons((uint16_t) *field), + htons((uint16_t) tos)); + *field = tos; + } + + if (nh->ip_ttl != ttl) { + uint8_t *field = &nh->ip_ttl; + + nh->ip_csum = recalc_csum16(nh->ip_csum, htons(*field << 8), + htons(ttl << 8)); + *field = ttl; + } +} + +static void +packet_set_port(ovs_be16 *port, ovs_be16 new_port, ovs_be16 *csum) +{ + if (*port != new_port) { + *csum = recalc_csum16(*csum, *port, new_port); + *port = new_port; + } +} + +/* Sets the TCP source and destination port ('src' and 'dst' respectively) of + * the TCP header contained in 'packet'. 'packet' must be a valid TCP packet + * with its l4 marker properly populated. */ +void +packet_set_tcp_port(struct ofpbuf *packet, ovs_be16 src, ovs_be16 dst) +{ + struct tcp_header *th = packet->l4; + + packet_set_port(&th->tcp_src, src, &th->tcp_csum); + packet_set_port(&th->tcp_dst, dst, &th->tcp_csum); +} + +/* Sets the UDP source and destination port ('src' and 'dst' respectively) of + * the UDP header contained in 'packet'. 'packet' must be a valid UDP packet + * with its l4 marker properly populated. */ +void +packet_set_udp_port(struct ofpbuf *packet, ovs_be16 src, ovs_be16 dst) +{ + struct udp_header *uh = packet->l4; + + if (uh->udp_csum) { + packet_set_port(&uh->udp_src, src, &uh->udp_csum); + packet_set_port(&uh->udp_dst, dst, &uh->udp_csum); + + if (!uh->udp_csum) { + uh->udp_csum = htons(0xffff); + } + } else { + uh->udp_src = src; + uh->udp_dst = dst; + } +}