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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:16:35 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-09 13:16:35 +0000
commite2bbf175a2184bd76f6c54ccf8456babeb1a46fc (patch)
treef0b76550d6e6f500ada964a3a4ee933a45e5a6f1 /vrrpd/vrrp_packet.h
parentInitial commit. (diff)
downloadfrr-e2bbf175a2184bd76f6c54ccf8456babeb1a46fc.tar.xz
frr-e2bbf175a2184bd76f6c54ccf8456babeb1a46fc.zip
Adding upstream version 9.1.upstream/9.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vrrpd/vrrp_packet.h')
-rw-r--r--vrrpd/vrrp_packet.h190
1 files changed, 190 insertions, 0 deletions
diff --git a/vrrpd/vrrp_packet.h b/vrrpd/vrrp_packet.h
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+++ b/vrrpd/vrrp_packet.h
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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * VRRP packet crafting.
+ * Copyright (C) 2018-2019 Cumulus Networks, Inc.
+ * Quentin Young
+ */
+#ifndef __VRRP_PACKET_H__
+#define __VRRP_PACKET_H__
+
+#include <zebra.h>
+
+#include "lib/ipaddr.h"
+#include "lib/memory.h"
+#include "lib/prefix.h"
+
+#define VRRP_TYPE_ADVERTISEMENT 1
+
+/*
+ * Shared header for VRRPv2/v3 packets.
+ */
+struct vrrp_hdr {
+ /*
+ * H L H L
+ * 0000 0000
+ * ver type
+ */
+ uint8_t vertype;
+ uint8_t vrid;
+ uint8_t priority;
+ uint8_t naddr;
+ union {
+ struct {
+ uint8_t auth_type;
+ /* advertisement interval (in sec) */
+ uint8_t adver_int;
+ } v2;
+ struct {
+ /*
+ * advertisement interval (in centiseconds)
+ * H L H L
+ * 0000 000000000000
+ * rsvd adver_int
+ */
+ uint16_t adver_int;
+ } v3;
+ };
+ uint16_t chksum;
+} __attribute__((packed));
+
+#define VRRP_HDR_SIZE sizeof(struct vrrp_hdr)
+
+struct vrrp_pkt {
+ struct vrrp_hdr hdr;
+ /*
+ * When used, this is actually an array of one or the other, not an
+ * array of union. If N v4 addresses are stored then
+ * sizeof(addrs) == N * sizeof(struct in_addr).
+ *
+ * Under v2, the last 2 entries in this array are the authentication
+ * data fields. We don't support auth in v2 so these are always just 8
+ * bytes of 0x00.
+ */
+ union {
+ struct in_addr v4;
+ struct in6_addr v6;
+ } addrs[];
+} __attribute__((packed));
+
+#define VRRP_PKT_SIZE(_f, _ver, _naddr) \
+ ({ \
+ size_t _asz = ((_f) == AF_INET) ? sizeof(struct in_addr) \
+ : sizeof(struct in6_addr); \
+ size_t _auth = 2 * sizeof(uint32_t) * (3 - (_ver)); \
+ sizeof(struct vrrp_hdr) + (_asz * (_naddr)) + _auth; \
+ })
+
+#define VRRP_MIN_PKT_SIZE_V4 VRRP_PKT_SIZE(AF_INET, 3, 1)
+#define VRRP_MAX_PKT_SIZE_V4 VRRP_PKT_SIZE(AF_INET, 2, 255)
+#define VRRP_MIN_PKT_SIZE_V6 VRRP_PKT_SIZE(AF_INET6, 3, 1)
+#define VRRP_MAX_PKT_SIZE_V6 VRRP_PKT_SIZE(AF_INET6, 3, 255)
+
+#define VRRP_MIN_PKT_SIZE VRRP_MIN_PKT_SIZE_V4
+#define VRRP_MAX_PKT_SIZE VRRP_MAX_PKT_SIZE_V6
+
+/*
+ * Builds a VRRP ADVERTISEMENT packet.
+ *
+ * pkt
+ * Pointer to store pointer to result buffer in
+ *
+ * src
+ * Source address packet will be transmitted from. This is needed to compute
+ * the VRRP checksum. The returned packet must be sent in an IP datagram with
+ * the source address equal to this field, or the checksum will be invalid.
+ *
+ * version
+ * VRRP version; must be 2 or 3
+ *
+ * vrid
+ * Virtual Router Identifier
+ *
+ * prio
+ * Virtual Router Priority
+ *
+ * max_adver_int
+ * time between ADVERTISEMENTs
+ *
+ * v6
+ * whether 'ips' is an array of v4 or v6 addresses
+ *
+ * numip
+ * number of IPvX addresses in 'ips'
+ *
+ * ips
+ * array of pointer to either struct in_addr (v6 = false) or struct in6_addr
+ * (v6 = true)
+ */
+ssize_t vrrp_pkt_adver_build(struct vrrp_pkt **pkt, struct ipaddr *src,
+ uint8_t version, uint8_t vrid, uint8_t prio,
+ uint16_t max_adver_int, uint8_t numip,
+ struct ipaddr **ips, bool ipv4_ph);
+
+/* free memory allocated by vrrp_pkt_adver_build's pkt arg */
+void vrrp_pkt_free(struct vrrp_pkt *pkt);
+
+/*
+ * Dumps a VRRP ADVERTISEMENT packet to a string.
+ *
+ * Currently only dumps the header.
+ *
+ * buf
+ * Buffer to store string representation
+ *
+ * buflen
+ * Size of buf
+ *
+ * pkt
+ * Packet to dump to a string
+ *
+ * Returns:
+ * # bytes written to buf
+ */
+size_t vrrp_pkt_adver_dump(char *buf, size_t buflen, struct vrrp_pkt *pkt);
+
+
+/*
+ * Parses a VRRP packet, checking for illegal or invalid data.
+ *
+ * This function parses both VRRPv2 and VRRPv3 packets. Which version is
+ * expected is determined by the version argument. For example, if version is 3
+ * and the received packet has version field 2 it will fail to parse.
+ *
+ * Note that this function only checks whether the packet itself is a valid
+ * VRRP packet. It is up to the caller to validate whether the VRID is correct,
+ * priority and timer values are correct, etc.
+ *
+ * family
+ * Address family of received packet
+ *
+ * version
+ * VRRP version to use for validation
+ *
+ * m
+ * msghdr containing results of recvmsg() on VRRP router socket
+ *
+ * read
+ * Return value of recvmsg() on VRRP router socket; must be non-negative
+ *
+ * src
+ * Pointer to struct ipaddr to store address of datagram sender
+ *
+ * pkt
+ * Pointer to pointer to set to location of VRRP packet within buf
+ *
+ * errmsg
+ * Buffer to store human-readable error message in case of error; may be
+ * NULL, in which case no message will be stored
+ *
+ * errmsg_len
+ * Size of errmsg
+ *
+ * Returns:
+ * Size of VRRP packet, or -1 upon error
+ */
+ssize_t vrrp_pkt_parse_datagram(int family, int version, bool ipv4_ph,
+ struct msghdr *m, size_t read,
+ struct ipaddr *src, struct vrrp_pkt **pkt,
+ char *errmsg, size_t errmsg_len);
+
+#endif /* __VRRP_PACKET_H__ */