/*
- * Copyright (c) 2009, 2010, 2011 Nicira Networks.
+ * Copyright (c) 2009, 2010, 2011, 2012 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <netinet/in.h>
#include <stdlib.h>
#include "byte-order.h"
+#include "csum.h"
+#include "flow.h"
#include "dynamic-string.h"
#include "ofpbuf.h"
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])
{
}
}
-/* 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
- * packet.
+ * packet. Ignores the CFI bit of 'tci' using 0 instead.
*
* Also sets 'packet->l2' to point to the new Ethernet header. */
void
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);
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;
+}
+
+void
+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 && !eth_mask_is_exact(mask)) {
+ ds_put_format(s, "/"ETH_ADDR_FMT, ETH_ADDR_ARGS(mask));
+ }
+}
+
+void
+eth_addr_bitand(const uint8_t src[ETH_ADDR_LEN],
+ const uint8_t mask[ETH_ADDR_LEN],
+ uint8_t dst[ETH_ADDR_LEN])
+{
+ int i;
+
+ for (i = 0; i < ETH_ADDR_LEN; i++) {
+ dst[i] = src[i] & mask[i];
+ }
+}
+
/* 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));
}
/* 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)
{
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;
/* 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. */
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.
+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;
+ }
+}
+
+/* If 'packet' is a TCP packet, returns the TCP flags. Otherwise, returns 0.
*
- * 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)
+ * '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)
{
- struct eth_header *eth;
- struct llc_snap_header *llc_snap;
- void *payload;
+ if ((flow->dl_type == htons(ETH_TYPE_IP) ||
+ flow->dl_type == htons(ETH_TYPE_IPV6)) &&
+ flow->nw_proto == IPPROTO_TCP && packet->l7) {
+ const struct tcp_header *tcp = packet->l4;
+ return TCP_FLAGS(tcp->tcp_ctl);
+ } else {
+ return 0;
+ }
+}
- /* 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);
+/* Appends a string representation of the TCP flags value 'tcp_flags'
+ * (e.g. obtained via packet_get_tcp_flags() or TCP_FLAGS) to 's', in the
+ * format used by tcpdump. */
+void
+packet_format_tcp_flags(struct ds *s, uint8_t tcp_flags)
+{
+ if (!tcp_flags) {
+ ds_put_cstr(s, "none");
+ return;
+ }
- /* 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;
+ if (tcp_flags & TCP_SYN) {
+ ds_put_char(s, 'S');
+ }
+ if (tcp_flags & TCP_FIN) {
+ ds_put_char(s, 'F');
+ }
+ if (tcp_flags & TCP_PSH) {
+ ds_put_char(s, 'P');
+ }
+ if (tcp_flags & TCP_RST) {
+ ds_put_char(s, 'R');
+ }
+ if (tcp_flags & TCP_URG) {
+ ds_put_char(s, 'U');
+ }
+ if (tcp_flags & TCP_ACK) {
+ ds_put_char(s, '.');
+ }
+ if (tcp_flags & 0x40) {
+ ds_put_cstr(s, "[40]");
+ }
+ if (tcp_flags & 0x80) {
+ ds_put_cstr(s, "[80]");
+ }
}