X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=lib%2Fpackets.c;h=9d861dab1c8996847bbe2cd8f287a9f72f05e65b;hb=a00ca915ff30a5cb7372cdf145205e339873cd4a;hp=83c852c138db5e87fe8b1a084460ef6b1db02da9;hpb=7c66b273a2addd3f6c60b6c930464d6be74df71e;p=sliver-openvswitch.git diff --git a/lib/packets.c b/lib/packets.c index 83c852c13..9d861dab1 100644 --- a/lib/packets.c +++ b/lib/packets.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2009, 2010, 2011 Nicira Networks. + * Copyright (c) 2009, 2010, 2011, 2012 Nicira Networks. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -18,9 +18,12 @@ #include "packets.h" #include #include +#include #include #include #include "byte-order.h" +#include "csum.h" +#include "flow.h" #include "dynamic-string.h" #include "ofpbuf.h" @@ -75,36 +78,100 @@ compose_benign_packet(struct ofpbuf *b, const char *tag, uint16_t snap_type, memcpy(payload + tag_size, eth_src, ETH_ADDR_LEN); } -/* Modify the TCI field of 'packet', whose data must begin with an Ethernet - * header. If a VLAN tag is present, its TCI field is replaced by 'tci'. If a - * VLAN tag is not present, one is added with the TCI field set to 'tci'. +/* Insert VLAN header according to given TCI. Packet passed must be Ethernet + * packet. Ignores the CFI bit of 'tci' using 0 instead. * * Also sets 'packet->l2' to point to the new Ethernet header. */ void -eth_set_vlan_tci(struct ofpbuf *packet, ovs_be16 tci) +eth_push_vlan(struct ofpbuf *packet, ovs_be16 tci) { struct eth_header *eh = packet->data; struct vlan_eth_header *veh; - if (packet->size >= sizeof(struct vlan_eth_header) - && eh->eth_type == htons(ETH_TYPE_VLAN)) { - veh = packet->data; - veh->veth_tci = tci; - } else { - /* Insert new 802.1Q header. */ - struct vlan_eth_header tmp; - 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_next_type = eh->eth_type; - - veh = ofpbuf_push_uninit(packet, VLAN_HEADER_LEN); - memcpy(veh, &tmp, sizeof tmp); - } + /* Insert new 802.1Q header. */ + struct vlan_eth_header tmp; + 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 & htons(~VLAN_CFI); + tmp.veth_next_type = eh->eth_type; + + veh = ofpbuf_push_uninit(packet, VLAN_HEADER_LEN); + memcpy(veh, &tmp, sizeof tmp); + 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()). */ +int +ip_count_cidr_bits(ovs_be32 netmask) +{ + assert(ip_is_cidr(netmask)); + return 32 - ctz(ntohl(netmask)); +} + +void +ip_format_masked(ovs_be32 ip, ovs_be32 mask, struct ds *s) +{ + ds_put_format(s, IP_FMT, IP_ARGS(&ip)); + if (mask != htonl(UINT32_MAX)) { + if (ip_is_cidr(mask)) { + ds_put_format(s, "/%d", ip_count_cidr_bits(mask)); + } else { + ds_put_format(s, "/"IP_FMT, IP_ARGS(&mask)); + } + } +} + + /* Stores the string representation of the IPv6 address 'addr' into the * character array 'addr_str', which must be at least INET6_ADDRSTRLEN * bytes long. */ @@ -117,10 +184,29 @@ format_ipv6_addr(char *addr_str, const struct in6_addr *addr) void print_ipv6_addr(struct ds *string, const struct in6_addr *addr) { - char addr_str[INET6_ADDRSTRLEN]; + char *dst; - format_ipv6_addr(addr_str, addr); - ds_put_format(string, "%s", addr_str); + ds_reserve(string, string->length + INET6_ADDRSTRLEN); + + dst = string->string + string->length; + format_ipv6_addr(dst, addr); + string->length += strlen(dst); +} + +void +print_ipv6_masked(struct ds *s, const struct in6_addr *addr, + const struct in6_addr *mask) +{ + print_ipv6_addr(s, addr); + if (mask && !ipv6_mask_is_exact(mask)) { + if (ipv6_is_cidr(mask)) { + int cidr_bits = ipv6_count_cidr_bits(mask); + ds_put_format(s, "/%d", cidr_bits); + } else { + ds_put_char(s, '/'); + print_ipv6_addr(s, mask); + } + } } struct in6_addr ipv6_addr_bitand(const struct in6_addr *a, @@ -164,9 +250,9 @@ ipv6_create_mask(int mask) return netmask; } -/* Given the IPv6 netmask 'netmask', returns the number of bits of the - * IPv6 address that it wildcards. 'netmask' must be a CIDR netmask (see - * ipv6_is_cidr()). */ +/* Given the IPv6 netmask 'netmask', returns the number of bits of the IPv6 + * address that it specifies, that is, the number of 1-bits in 'netmask'. + * 'netmask' must be a CIDR netmask (see ipv6_is_cidr()). */ int ipv6_count_cidr_bits(const struct in6_addr *netmask) { @@ -221,7 +307,11 @@ 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. */ void * eth_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN], const uint8_t eth_src[ETH_ADDR_LEN], uint16_t eth_type, @@ -232,7 +322,8 @@ eth_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN], ofpbuf_clear(b); - ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + size); + ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + VLAN_HEADER_LEN + size); + ofpbuf_reserve(b, VLAN_HEADER_LEN); eth = ofpbuf_put_uninit(b, ETH_HEADER_LEN); data = ofpbuf_put_uninit(b, size); @@ -240,13 +331,19 @@ 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; } /* Populates 'b' with an Ethernet LLC+SNAP packet headed with the given * 'eth_dst', 'eth_src', 'snap_org', and 'snap_type'. A payload of 'size' * bytes is allocated in 'b' and returned. This payload may be populated with - * appropriate information by the caller. */ + * appropriate information by the caller. + * + * The returned packet has enough headroom to insert an 802.1Q VLAN header if + * desired. */ void * snap_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN], const uint8_t eth_src[ETH_ADDR_LEN], @@ -259,7 +356,9 @@ snap_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN], /* Compose basic packet structure. (We need the payload size to stick into * the 802.2 header.) */ ofpbuf_clear(b); - ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + LLC_SNAP_HEADER_LEN + size); + ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + VLAN_HEADER_LEN + + LLC_SNAP_HEADER_LEN + size); + ofpbuf_reserve(b, VLAN_HEADER_LEN); eth = ofpbuf_put_zeros(b, ETH_HEADER_LEN); llc_snap = ofpbuf_put_zeros(b, LLC_SNAP_HEADER_LEN); payload = ofpbuf_put_uninit(b, size); @@ -281,45 +380,119 @@ snap_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN], return payload; } -/* Populates 'pdu' with a LACP PDU comprised of 'actor' and 'partner'. */ +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 -compose_lacp_pdu(const struct lacp_info *actor, - const struct lacp_info *partner, struct lacp_pdu *pdu) +packet_set_ipv4(struct ofpbuf *packet, ovs_be32 src, ovs_be32 dst, + uint8_t tos, uint8_t ttl) { - memset(pdu, 0, sizeof *pdu); + struct ip_header *nh = packet->l3; - pdu->subtype = 1; - pdu->version = 1; + if (nh->ip_src != src) { + packet_set_ipv4_addr(packet, &nh->ip_src, src); + } - pdu->actor_type = 1; - pdu->actor_len = 20; - pdu->actor = *actor; + 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; + } - pdu->partner_type = 2; - pdu->partner_len = 20; - pdu->partner = *partner; + if (nh->ip_ttl != ttl) { + uint8_t *field = &nh->ip_ttl; - pdu->collector_type = 3; - pdu->collector_len = 16; - pdu->collector_delay = htons(0); + 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); } -/* Parses 'b' which represents a packet containing a LACP PDU. This function - * returns NULL if 'b' is malformed, or does not represent a LACP PDU format - * supported by OVS. Otherwise, it returns a pointer to the lacp_pdu contained - * within 'b'. */ -const struct lacp_pdu * -parse_lacp_packet(const struct ofpbuf *b) +/* 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) { - const struct lacp_pdu *pdu; + struct udp_header *uh = packet->l4; - pdu = ofpbuf_at(b, (uint8_t *)b->l3 - (uint8_t *)b->data, LACP_PDU_LEN); + 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 (pdu && pdu->subtype == 1 - && pdu->actor_type == 1 && pdu->actor_len == 20 - && pdu->partner_type == 2 && pdu->partner_len == 20) { - return pdu; + if (!uh->udp_csum) { + uh->udp_csum = htons(0xffff); + } + } else { + uh->udp_src = src; + uh->udp_dst = dst; + } +} + +/* If 'packet' is a TCP packet, returns the TCP flags. Otherwise, returns 0. + * + * 'flow' must be the flow corresponding to 'packet' and 'packet''s header + * pointers must be properly initialized (e.g. with flow_extract()). */ +uint8_t +packet_get_tcp_flags(const struct ofpbuf *packet, const struct flow *flow) +{ + /* XXX IPv6? */ + if (flow->dl_type == htons(ETH_TYPE_IP) && packet->l4 + && flow->nw_proto == IPPROTO_TCP && packet->l7) { + const struct tcp_header *tcp = packet->l4; + return TCP_FLAGS(tcp->tcp_ctl); } else { - return NULL; + return 0; } }