X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=lib%2Fpackets.c;h=57291674ac5db6ce38d6bb0379e93dc2560f994c;hb=479df1769d51351d031482acaaf0c713726c05d1;hp=b3851280a31f1a64ea05749af501b9c11c6fb4b7;hpb=3b4d8ad3070ad30da9cf52d4f2abf792bc07f20d;p=openvswitch diff --git a/lib/packets.c b/lib/packets.c index b3851280..57291674 100644 --- a/lib/packets.c +++ b/lib/packets.c @@ -43,6 +43,71 @@ dpid_from_string(const char *s, uint64_t *dpidp) return *dpidp != 0; } +/* Returns true if 'ea' is a reserved multicast address, that a bridge must + * never forward, false otherwise. Includes some proprietary vendor protocols + * that shouldn't be forwarded as well. + * + * If you change this function's behavior, please update corresponding + * documentation in vswitch.xml at the same time. */ +bool +eth_addr_is_reserved(const uint8_t ea[ETH_ADDR_LEN]) +{ + struct masked_eth_addr { + uint8_t ea[ETH_ADDR_LEN]; + uint8_t mask[ETH_ADDR_LEN]; + }; + + static struct masked_eth_addr mea[] = { + { /* STP, IEEE pause frames, and other reserved protocols. */ + {0x01, 0x08, 0xc2, 0x00, 0x00, 0x00}, + {0xff, 0xff, 0xff, 0xff, 0xff, 0xf0}}, + + { /* VRRP IPv4. */ + {0x00, 0x00, 0x5e, 0x00, 0x01, 0x00}, + {0xff, 0xff, 0xff, 0xff, 0xff, 0x00}}, + + { /* VRRP IPv6. */ + {0x00, 0x00, 0x5e, 0x00, 0x02, 0x00}, + {0xff, 0xff, 0xff, 0xff, 0xff, 0x00}}, + + { /* HSRPv1. */ + {0x00, 0x00, 0x0c, 0x07, 0xac, 0x00}, + {0xff, 0xff, 0xff, 0xff, 0xff, 0x00}}, + + { /* HSRPv2. */ + {0x00, 0x00, 0x0c, 0x9f, 0xf0, 0x00}, + {0xff, 0xff, 0xff, 0xff, 0xf0, 0x00}}, + + { /* GLBP. */ + {0x00, 0x07, 0xb4, 0x00, 0x00, 0x00}, + {0xff, 0xff, 0xff, 0x00, 0x00, 0x00}}, + + { /* Extreme Discovery Protocol. */ + {0x00, 0xE0, 0x2B, 0x00, 0x00, 0x00}, + {0xff, 0xff, 0xff, 0xff, 0xf0, 0x00}}, + + { /* Cisco Inter Switch Link. */ + {0x01, 0x00, 0x0c, 0x00, 0x00, 0x00}, + {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}}, + + { /* Cisco protocols plus others following the same pattern: + * + * CDP, VTP, DTP, PAgP (01-00-0c-cc-cc-cc) + * Spanning Tree PVSTP+ (01-00-0c-cc-cc-cd) + * STP Uplink Fast (01-00-0c-cd-cd-cd) */ + {0x01, 0x00, 0x0c, 0xcc, 0xcc, 0xcc}, + {0xff, 0xff, 0xff, 0xfe, 0xfe, 0xfe}}}; + + size_t i; + + for (i = 0; i < ARRAY_SIZE(mea); i++) { + if (eth_addr_equal_except(ea, mea[i].ea, mea[i].mask)) { + return true; + } + } + return false; +} + bool eth_addr_from_string(const char *s, uint8_t ea[ETH_ADDR_LEN]) { @@ -55,27 +120,37 @@ eth_addr_from_string(const char *s, uint8_t ea[ETH_ADDR_LEN]) } } -/* Fills 'b' with an 802.2 SNAP packet with Ethernet source address 'eth_src', - * the Nicira OUI as SNAP organization and 'snap_type' as SNAP type. The text - * string in 'tag' is enclosed as the packet payload. - * +/* Fills 'b' with a Reverse ARP packet with Ethernet source address 'eth_src'. * This function is used by Open vSwitch to compose packets in cases where - * context is important but content doesn't (or shouldn't) matter. For this - * purpose, 'snap_type' should be a random number and 'tag' should be an - * English phrase that explains the purpose of the packet. (The English phrase - * gives hapless admins running Wireshark the opportunity to figure out what's - * going on.) */ + * context is important but content doesn't (or shouldn't) matter. + * + * The returned packet has enough headroom to insert an 802.1Q VLAN header if + * desired. */ void -compose_benign_packet(struct ofpbuf *b, const char *tag, uint16_t snap_type, - const uint8_t eth_src[ETH_ADDR_LEN]) +compose_rarp(struct ofpbuf *b, const uint8_t eth_src[ETH_ADDR_LEN]) { - size_t tag_size = strlen(tag) + 1; - char *payload; + struct eth_header *eth; + struct rarp_header *rarp; - payload = snap_compose(b, eth_addr_broadcast, eth_src, 0x002320, snap_type, - tag_size + ETH_ADDR_LEN); - memcpy(payload, tag, tag_size); - memcpy(payload + tag_size, eth_src, ETH_ADDR_LEN); + ofpbuf_clear(b); + ofpbuf_prealloc_tailroom(b, ETH_HEADER_LEN + VLAN_HEADER_LEN + + RARP_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); } /* Insert VLAN header according to given TCI. Packet passed must be Ethernet @@ -153,7 +228,7 @@ eth_format_masked(const uint8_t eth[ETH_ADDR_LEN], const uint8_t mask[ETH_ADDR_LEN], struct ds *s) { ds_put_format(s, ETH_ADDR_FMT, ETH_ADDR_ARGS(eth)); - if (mask) { + if (mask && !eth_mask_is_exact(mask)) { ds_put_format(s, "/"ETH_ADDR_FMT, ETH_ADDR_ARGS(mask)); } } @@ -171,12 +246,13 @@ eth_addr_bitand(const uint8_t src[ETH_ADDR_LEN], } /* 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()). */ + * that it specifies, that is, the number of 1-bits in 'netmask'. + * + * If 'netmask' is not a CIDR netmask (see ip_is_cidr()), the return value will + * still be in the valid range but isn't otherwise meaningful. */ int ip_count_cidr_bits(ovs_be32 netmask) { - assert(ip_is_cidr(netmask)); return 32 - ctz(ntohl(netmask)); } @@ -274,7 +350,10 @@ ipv6_create_mask(int mask) /* 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()). */ + * 'netmask' must be a CIDR netmask (see ipv6_is_cidr()). + * + * If 'netmask' is not a CIDR netmask (see ipv6_is_cidr()), the return value + * will still be in the valid range but isn't otherwise meaningful. */ int ipv6_count_cidr_bits(const struct in6_addr *netmask) { @@ -282,8 +361,6 @@ ipv6_count_cidr_bits(const struct in6_addr *netmask) int count = 0; const uint8_t *netmaskp = &netmask->s6_addr[0]; - assert(ipv6_is_cidr(netmask)); - for (i=0; i<16; i++) { if (netmaskp[i] == 0xff) { count += 8; @@ -359,49 +436,6 @@ eth_compose(struct ofpbuf *b, const uint8_t eth_dst[ETH_ADDR_LEN], 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. - * - * 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], - unsigned int oui, uint16_t snap_type, size_t size) -{ - struct eth_header *eth; - struct llc_snap_header *llc_snap; - void *payload; - - /* 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 + 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); - - /* Compose 802.2 header. */ - memcpy(eth->eth_dst, eth_dst, ETH_ADDR_LEN); - memcpy(eth->eth_src, eth_src, ETH_ADDR_LEN); - eth->eth_type = htons(b->size - ETH_HEADER_LEN); - - /* Compose LLC, SNAP headers. */ - llc_snap->llc.llc_dsap = LLC_DSAP_SNAP; - llc_snap->llc.llc_ssap = LLC_SSAP_SNAP; - llc_snap->llc.llc_cntl = LLC_CNTL_SNAP; - llc_snap->snap.snap_org[0] = oui >> 16; - llc_snap->snap.snap_org[1] = oui >> 8; - llc_snap->snap.snap_org[2] = oui; - llc_snap->snap.snap_type = htons(snap_type); - - return payload; -} - static void packet_set_ipv4_addr(struct ofpbuf *packet, ovs_be32 *addr, ovs_be32 new_addr) {