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send_map_request.c
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send_map_request.c
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/*
* send_map_request.c
*
* By David Meyer <[email protected]>
* Copyright 2009 David Meyer
*
* Functions related to sending a map-request
*
* David Meyer
* Tue Apr 14 14:48:13 2009
*
* IPv6 support added by Lorand Jakab <[email protected]>
* Mon Aug 23 15:26:51 2010 +0200
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* o Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* o Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* o Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*
*
* $Header: /mnt/disk1/dmm/src/lig/RCS/send_map_request.c,v 1.1 2010/11/14 20:48:35 dmm Exp $
*
*/
#include "lig.h"
#include "lig-external.h"
/*
* send_map_request --
*
* Sends a IP/UDP encapsulated map-request for eid to map_server
*
*
* Here's the packet we need to build:
*
* IP header (ip.src = <us>, ip.dst = <map-resolver>)
* UDP header (udp.srcport = <kernel>, udp.dstport = 4342)
* lcp -> lisp_control_pkt
* packet,iph -> IP header (ip.src = <this host>, ip.dst = eid)
* udph -> UDP (udp.srcport = ANY, udp.dstport = 4342)
* map_request -> struct map-request
*
* We'll open a UDP socket on dest port 4342, and
* give it a "packet" that that looks like:
*
* lcp -> lisp_control_pkt
* packet,iph -> IP header (SRC = this host, DEST = eid)
* udph -> UDP (DEST PORT = 4342)
* map_request -> struct map-request
*
*
* David Meyer
* Thu Apr 16 14:46:51 2009
*
* $Header: /mnt/disk1/dmm/src/lig/RCS/send_map_request.c,v 1.1 2010/11/14 20:48:35 dmm Exp $
*
*/
int send_map_request(s,nonce0,nonce1,before,eid_addr,map_resolver_addr,my_addr)
int s;
unsigned int nonce0;
unsigned int nonce1;
struct timeval *before;
struct sockaddr *eid_addr;
struct sockaddr *map_resolver_addr;
struct sockaddr *my_addr;
{
unsigned int ip_len = 0;
unsigned int udp_len = 0;
unsigned int packet_len = 0;
int nbytes = 0;
int e = 0;
char buf1[NI_MAXHOST];
char buf2[NI_MAXHOST];
uchar packet[MAX_IP_PACKET];
struct lisp_control_pkt *lcp;
struct ip *iph;
struct ip6_hdr *ip6h;
struct udphdr *udph;
struct map_request_pkt *map_request;
struct map_request_eid *map_request_eid;
/*
* The source address in the inner IP header
*
* Its address family depends on the destination EID, regardless of the
* Map-Resolver. If the host has no usable IPv6 address, the "::" address
* will be used.
*
*/
struct sockaddr_storage inner_src;
if (get_my_ip_addr(eid_addr->sa_family,&inner_src)) {
struct addrinfo hints;
struct addrinfo *res;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = eid_addr->sa_family;
hints.ai_socktype = 0;
hints.ai_flags = AI_NUMERICHOST;
hints.ai_protocol = 0;
hints.ai_canonname = NULL;
hints.ai_addr = NULL;
hints.ai_next = NULL;
/* Update IPv6 with the v4 mapped address instead of :: */
if ((e = getaddrinfo(
(eid_addr->sa_family == AF_INET) ? "0.0.0.0" : "::",
NULL, &hints, &res)) != 0) {
fprintf(stderr, "getting local socket: getaddrinfo: %s\n", gai_strerror(e));
exit(BAD);
}
memcpy(&inner_src, res->ai_addr, res->ai_addrlen);
freeaddrinfo(res);
}
if (debug > 2) {
getnameinfo((struct sockaddr *)&inner_src,
SA_LEN(((struct sockaddr *)&inner_src)->sa_family),
buf1,NI_MAXHOST,NULL,0,NI_NUMERICHOST);
getnameinfo(eid_addr,SA_LEN(eid_addr->sa_family),buf2,NI_MAXHOST,NULL,0,NI_NUMERICHOST);
fprintf(stderr, "send_map_request (inner header): <%s:%d,%s:%d>\n",
buf1,
emr_inner_src_port,
buf2,
LISP_CONTROL_PORT);
}
/*
* make sure packet is clean
*/
memset(packet, 0, MAX_IP_PACKET);
/*
* Build the packet.
*
* The packet has the following form:
*
* outer-ip-header built by the kernel
* udp-header (4342) built by the kernel
* lisp lisp control packet struct lisp_control_pkt *lcp
* inner-ip-header struct ip *iphdr
* udp-header (4342) struct udphdr *udphdr
* lisp-header (map-request) struct map_request_pkt *map_request
*/
/*
* CO is a macro that makes sure the pointer
* arithmetic is done correctly. Basically...
*
* #define CO(addr,len) (((char *) addr + len))
*
*/
lcp = (struct lisp_control_pkt *) packet;
if (eid_addr->sa_family == AF_INET) {
iph = (struct ip *) CO(lcp, sizeof(struct lisp_control_pkt));
ip6h = NULL;
udph = (struct udphdr *) CO(iph, sizeof(struct ip));
} else {
iph = NULL;
ip6h = (struct ip6_hdr *) CO(lcp, sizeof(struct lisp_control_pkt));
udph = (struct udphdr *) CO(ip6h, sizeof(struct ip6_hdr));
}
map_request = (struct map_request_pkt *) CO(udph, sizeof(struct udphdr));
if (my_addr->sa_family == AF_INET)
map_request_eid = (struct map_request_eid *) CO(map_request, sizeof(struct map_request_pkt) + sizeof(struct in_addr));
else
map_request_eid = (struct map_request_eid *) CO(map_request, sizeof(struct map_request_pkt) + sizeof(struct in6_addr));
/*
* compute lengths of interest
*/
udp_len = sizeof(struct udphdr) + sizeof(struct map_request_pkt)
+ sizeof(struct map_request_eid);
if (my_addr->sa_family == AF_INET)
udp_len = udp_len + sizeof(struct in_addr);
else
udp_len = udp_len + sizeof(struct in6_addr);
if (eid_addr->sa_family == AF_INET) {
udp_len = udp_len + sizeof(struct in_addr);
ip_len = udp_len + sizeof(struct ip);
} else {
udp_len = udp_len + sizeof(struct in6_addr);
ip_len = udp_len + sizeof(struct ip6_hdr);
}
packet_len = ip_len + sizeof(struct lisp_control_pkt);
/*
* Tell the Map Resolver its an LISP Encapsulated control packet
*/
lcp->type = LISP_ENCAP_CONTROL_TYPE;
/*
* Build inner IP header
*
* packet,iph -> IP header (SRC = this host, DEST = EID)
*
*/
if (eid_addr->sa_family == AF_INET) {
iph->ip_hl = 5;
iph->ip_v = 4;
iph->ip_tos = 0;
iph->ip_len = htons(ip_len); /* ip + udp headers, + map_request */
iph->ip_id = htons(54321); /* the value doesn't matter here */
iph->ip_off = 0;
iph->ip_ttl = 255;
iph->ip_p = IPPROTO_UDP;
iph->ip_sum = 0; /* compute checksum later */
iph->ip_src.s_addr = ((struct sockaddr_in *)&inner_src)->sin_addr.s_addr;
iph->ip_dst.s_addr = ((struct sockaddr_in *)eid_addr)->sin_addr.s_addr;
} else {
ip6h->ip6_vfc = 0x6E;
ip6h->ip6_plen = htons(udp_len); /* udp header + map_request */
ip6h->ip6_nxt = IPPROTO_UDP;
ip6h->ip6_hlim = 64;
ip6h->ip6_src = ((struct sockaddr_in6 *)&inner_src)->sin6_addr;
ip6h->ip6_dst = ((struct sockaddr_in6 *)eid_addr)->sin6_addr;
}
/*
* Build UDP inner header
*
* DEST Port is 4342 (LISP Control)
*/
#ifdef BSD
udph->uh_sport = htons(emr_inner_src_port);
udph->uh_dport = htons(LISP_CONTROL_PORT);
udph->uh_ulen = htons(udp_len);
udph->uh_sum = 0;
#else
udph->source = htons(emr_inner_src_port);
udph->dest = htons(LISP_CONTROL_PORT);
udph->len = htons(udp_len);
udph->check = 0;
#endif
/*
* Build the Map-Request
*
* Map-Request Message Format
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |Type=1 |A|M|P|S| Reserved | IRC | Record Count |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Nonce . . . |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | . . . Nonce |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Source-EID-AFI | Source EID Address ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ITR-RLOC-AFI 1 | ITR-RLOC Address 1 ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | ITR-RLOC-AFI n | ITR-RLOC Address n ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* / | Reserved | EID mask-len | EID-prefix-AFI |
* Rec +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* \ | EID-prefix ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Map-Reply Record ... |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | Mapping Protocol Data |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
/*
* We set Source-EID-AFI to 0 and skip the Source EID Address field
*/
map_request->smr_bit = 0;
map_request->rloc_probe = 0;
map_request->map_data_present = 0;
map_request->auth_bit = 0;
map_request->lisp_type = LISP_MAP_REQUEST;
map_request->irc = 0;
map_request->record_count = 1;
map_request->lisp_nonce0 = htonl(nonce0);
map_request->lisp_nonce1 = htonl(nonce1);
map_request->source_eid_afi = 0;
if (my_addr->sa_family == AF_INET) {
map_request->itr_afi = htons(LISP_AFI_IP);
memcpy(&(map_request->originating_itr_rloc),
&(((struct sockaddr_in *)my_addr)->sin_addr), sizeof(struct in_addr));
} else {
map_request->itr_afi = htons(LISP_AFI_IPV6);
memcpy(&(map_request->originating_itr_rloc),
&(((struct sockaddr_in6 *)my_addr)->sin6_addr), sizeof(struct in6_addr));
}
if (eid_addr->sa_family == AF_INET) {
map_request_eid->eid_mask_len = LISP_IP_MASK_LEN;
map_request_eid->eid_prefix_afi = htons(LISP_AFI_IP);
memcpy(&map_request_eid->eid_prefix,
&(((struct sockaddr_in *)eid_addr)->sin_addr), sizeof(struct in_addr));
iph->ip_sum = ip_checksum(packet,ip_len);
} else {
map_request_eid->eid_mask_len = LISP_IPV6_MASK_LEN;
map_request_eid->eid_prefix_afi = htons(LISP_AFI_IPV6);
memcpy(&map_request_eid->eid_prefix,
&(((struct sockaddr_in6 *)eid_addr)->sin6_addr), sizeof(struct in6_addr));
}
if (udp_checksum_disabled)
udpsum(udph) = 0;
else {
if (eid_addr->sa_family == AF_INET)
udpsum(udph) = udp_checksum(udph,udp_len,iph->ip_src.s_addr,iph->ip_dst.s_addr);
else
udpsum(udph) = udp6_checksum(ip6h,udph,udp_len);
}
/*
* Set up to talk to the map-resolver
*
* Kernel puts on:
*
* IP (SRC = my_addr, DEST = map_resolver)
* UDP (DEST PORT = 4342)
*
* The UDP packet we build (packet) looks like:
*
* IP (SRC = my_addr, DEST = eid)
* UDP (DEST PORT = 4342)
* map-request_pkt
*
*/
if (gettimeofday(before,NULL) == -1) {
perror("gettimeofday");
return(BAD);
}
if ((nbytes = sendto(s,
(const void *) packet,
packet_len,
0,
map_resolver_addr,
SA_LEN(map_resolver_addr->sa_family))) < 0) {
perror("sendto");
exit(BAD);
}
if (nbytes != packet_len) {
fprintf(stderr,
"send_map_request: nbytes (%d) != packet_len(%d)\n",
nbytes, packet_len);
exit(BAD);
}
return(GOOD);
}