X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fpackets.c;h=fa73b50a043246a3944fbd4bd8e216636216668f;hb=558e2cc58e16f6e3cee44926d69d385d84d42521;hp=687a84c5d2a461de791fb8ed28b5e2dd4019c8ad;hpb=7d48a4cca4c426bbad5872eb9f062b8735adbe8c;p=openvswitch diff --git a/lib/packets.c b/lib/packets.c index 687a84c5..fa73b50a 100644 --- a/lib/packets.c +++ b/lib/packets.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include "byte-order.h" #include "csum.h" @@ -143,27 +144,27 @@ void compose_rarp(struct ofpbuf *b, const uint8_t eth_src[ETH_ADDR_LEN]) { struct eth_header *eth; - struct rarp_header *rarp; + struct arp_eth_header *arp; ofpbuf_clear(b); ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + VLAN_HEADER_LEN - + RARP_HEADER_LEN); + + ARP_ETH_HEADER_LEN); ofpbuf_reserve(b, VLAN_HEADER_LEN); eth = ofpbuf_put_uninit(b, sizeof *eth); memcpy(eth->eth_dst, eth_addr_broadcast, ETH_ADDR_LEN); memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN); eth->eth_type = htons(ETH_TYPE_RARP); - rarp = ofpbuf_put_uninit(b, sizeof *rarp); - rarp->hw_addr_space = htons(ARP_HTYPE_ETH); - rarp->proto_addr_space = htons(ETH_TYPE_IP); - rarp->hw_addr_length = ETH_ADDR_LEN; - rarp->proto_addr_length = sizeof rarp->src_proto_addr; - rarp->opcode = htons(RARP_REQUEST_REVERSE); - memcpy(rarp->src_hw_addr, eth_src, ETH_ADDR_LEN); - rarp->src_proto_addr = htonl(0); - memcpy(rarp->target_hw_addr, eth_src, ETH_ADDR_LEN); - rarp->target_proto_addr = htonl(0); + arp = ofpbuf_put_uninit(b, sizeof *arp); + arp->ar_hrd = htons(ARP_HRD_ETHERNET); + arp->ar_pro = htons(ARP_PRO_IP); + arp->ar_hln = sizeof arp->ar_sha; + arp->ar_pln = sizeof arp->ar_spa; + arp->ar_op = htons(ARP_OP_RARP); + memcpy(arp->ar_sha, eth_src, ETH_ADDR_LEN); + arp->ar_spa = htonl(0); + memcpy(arp->ar_tha, eth_src, ETH_ADDR_LEN); + arp->ar_tpa = htonl(0); } /* Insert VLAN header according to given TCI. Packet passed must be Ethernet @@ -472,6 +473,133 @@ packet_set_ipv4_addr(struct ofpbuf *packet, ovs_be32 *addr, ovs_be32 new_addr) *addr = new_addr; } +/* Returns true, if packet contains at least one routing header where + * segements_left > 0. + * + * This function assumes that L3 and L4 markers are set in the packet. */ +static bool +packet_rh_present(struct ofpbuf *packet) +{ + const struct ip6_hdr *nh; + int nexthdr; + size_t len; + size_t remaining; + uint8_t *data = packet->l3; + + remaining = (uint8_t *)packet->l4 - (uint8_t *)packet->l3; + + if (remaining < sizeof *nh) { + return false; + } + nh = (struct ip6_hdr *)data; + data += sizeof *nh; + remaining -= sizeof *nh; + nexthdr = nh->ip6_nxt; + + while (1) { + if ((nexthdr != IPPROTO_HOPOPTS) + && (nexthdr != IPPROTO_ROUTING) + && (nexthdr != IPPROTO_DSTOPTS) + && (nexthdr != IPPROTO_AH) + && (nexthdr != IPPROTO_FRAGMENT)) { + /* It's either a terminal header (e.g., TCP, UDP) or one we + * don't understand. In either case, we're done with the + * packet, so use it to fill in 'nw_proto'. */ + break; + } + + /* We only verify that at least 8 bytes of the next header are + * available, but many of these headers are longer. Ensure that + * accesses within the extension header are within those first 8 + * bytes. All extension headers are required to be at least 8 + * bytes. */ + if (remaining < 8) { + return false; + } + + if (nexthdr == IPPROTO_AH) { + /* A standard AH definition isn't available, but the fields + * we care about are in the same location as the generic + * option header--only the header length is calculated + * differently. */ + const struct ip6_ext *ext_hdr = (struct ip6_ext *)data; + + nexthdr = ext_hdr->ip6e_nxt; + len = (ext_hdr->ip6e_len + 2) * 4; + } else if (nexthdr == IPPROTO_FRAGMENT) { + const struct ip6_frag *frag_hdr = (struct ip6_frag *)data; + + nexthdr = frag_hdr->ip6f_nxt; + len = sizeof *frag_hdr; + } else if (nexthdr == IPPROTO_ROUTING) { + const struct ip6_rthdr *rh = (struct ip6_rthdr *)data; + + if (rh->ip6r_segleft > 0) { + return true; + } + + nexthdr = rh->ip6r_nxt; + len = (rh->ip6r_len + 1) * 8; + } else { + const struct ip6_ext *ext_hdr = (struct ip6_ext *)data; + + nexthdr = ext_hdr->ip6e_nxt; + len = (ext_hdr->ip6e_len + 1) * 8; + } + + if (remaining < len) { + return false; + } + remaining -= len; + data += len; + } + + return false; +} + +static void +packet_update_csum128(struct ofpbuf *packet, uint8_t proto, + ovs_be32 addr[4], const ovs_be32 new_addr[4]) +{ + if (proto == IPPROTO_TCP && packet->l7) { + struct tcp_header *th = packet->l4; + + th->tcp_csum = recalc_csum128(th->tcp_csum, addr, new_addr); + } else if (proto == IPPROTO_UDP && packet->l7) { + struct udp_header *uh = packet->l4; + + if (uh->udp_csum) { + uh->udp_csum = recalc_csum128(uh->udp_csum, addr, new_addr); + if (!uh->udp_csum) { + uh->udp_csum = htons(0xffff); + } + } + } +} + +static void +packet_set_ipv6_addr(struct ofpbuf *packet, uint8_t proto, + struct in6_addr *addr, const ovs_be32 new_addr[4], + bool recalculate_csum) +{ + if (recalculate_csum) { + packet_update_csum128(packet, proto, (ovs_be32 *)addr, new_addr); + } + memcpy(addr, new_addr, sizeof(*addr)); +} + +static void +packet_set_ipv6_flow_label(ovs_be32 *flow_label, ovs_be32 flow_key) +{ + *flow_label = (*flow_label & htonl(~IPV6_LABEL_MASK)) | flow_key; +} + +static void +packet_set_ipv6_tc(ovs_be32 *flow_label, uint8_t tc) +{ + *flow_label = (*flow_label & htonl(0xF00FFFFF)) | htonl(tc << 20); +} + /* 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] @@ -507,6 +635,33 @@ packet_set_ipv4(struct ofpbuf *packet, ovs_be32 src, ovs_be32 dst, } } +/* Modifies the IPv6 header fields of 'packet' to be consistent with 'src', + * 'dst', 'traffic class', and 'next hop'. Updates 'packet''s L4 checksums as + * appropriate. 'packet' must contain a valid IPv6 packet with correctly + * populated l[347] markers. */ +void +packet_set_ipv6(struct ofpbuf *packet, uint8_t proto, const ovs_be32 src[4], + const ovs_be32 dst[4], uint8_t key_tc, ovs_be32 key_fl, + uint8_t key_hl) +{ + struct ip6_hdr *nh = packet->l3; + + if (memcmp(&nh->ip6_src, src, sizeof(ovs_be32[4]))) { + packet_set_ipv6_addr(packet, proto, &nh->ip6_src, src, true); + } + + if (memcmp(&nh->ip6_dst, dst, sizeof(ovs_be32[4]))) { + packet_set_ipv6_addr(packet, proto, &nh->ip6_dst, dst, + !packet_rh_present(packet)); + } + + packet_set_ipv6_tc(&nh->ip6_flow, key_tc); + + packet_set_ipv6_flow_label(&nh->ip6_flow, key_fl); + + nh->ip6_hlim = key_hl; +} + static void packet_set_port(ovs_be16 *port, ovs_be16 new_port, ovs_be16 *csum) {