freebsd-dev/usr.sbin/mrouted/ipip.c

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/*
* The mrouted program is covered by the license in the accompanying file
* named "LICENSE". Use of the mrouted program represents acceptance of
* the terms and conditions listed in that file.
*
* The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
* Leland Stanford Junior University.
*
*
* ipip.c,v 3.8.4.6 1998/01/06 01:57:45 fenner Exp
*/
#include "defs.h"
#ifndef lint
static char rcsid[] = "@(#) $Id: \
ipip.c,v 3.8.4.6 1998/01/06 01:57:45 fenner Exp $";
#endif
/*
* Exported variables.
*/
#ifdef notyet
int raw_socket; /* socket for raw network I/O */
#endif
/*
*XXX For now, we just use the IGMP socket to send packets.
* This is legal in BSD, because the protocol # is not checked
* on raw sockets. The k_* interfaces need to gain a socket
* argument so that we can call them on the raw_socket also.
*/
#define raw_socket igmp_socket
/*
* Private variables.
*/
static int rawid = 0;
/*
* Open and initialize the raw socket.
*/
void
init_ipip()
{
#ifdef notyet
if ((raw_socket = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
log(LOG_ERR, errno, "Raw IP socket");
#endif
}
/*
* Allocate and fill in static IP header for encapsulating on a tunnel.
*/
void
init_ipip_on_vif(v)
struct uvif *v;
{
struct ip *ip;
ip = v->uv_encap_hdr = (struct ip *)malloc(sizeof(struct ip));
if (ip == NULL)
log(LOG_ERR, 0, "out of memory");
bzero(ip, sizeof(struct ip));
/*
* Fields zeroed that aren't filled in later:
* - IP ID (let the kernel fill it in)
* - Offset (we don't send fragments)
* - Checksum (let the kernel fill it in)
*/
ip->ip_v = IPVERSION;
ip->ip_hl = sizeof(struct ip) >> 2;
ip->ip_tos = 0xc0; /* Internet Control */
ip->ip_ttl = MAXTTL; /* applies to unicasts only */
ip->ip_p = IPPROTO_IPIP;
ip->ip_src.s_addr = v->uv_lcl_addr;
ip->ip_dst.s_addr = v->uv_rmt_addr;
}
/*
* Call build_igmp() to build an IGMP message in the output packet buffer.
* Then fill in the fields of the IP packet that build_igmp() left for the
* kernel to fill in, and encapsulate the original packet with the
* pre-created ip header for this vif.
*/
void
send_ipip(src, dst, type, code, group, datalen, v)
u_int32 src, dst;
int type, code;
u_int32 group;
int datalen;
struct uvif *v;
{
struct msghdr msg;
struct iovec iov[2];
struct sockaddr_in sdst;
struct ip *ip;
build_igmp(src, dst, type, code, group, datalen);
ip = (struct ip *)send_buf;
#ifndef RAW_OUTPUT_IS_RAW
ip->ip_len = htons(ip->ip_len);
#endif
ip->ip_id = htons(rawid++);
ip->ip_sum = 0;
ip->ip_sum = inet_cksum((u_short *)ip, ip->ip_hl << 2);
ip = v->uv_encap_hdr;
ip->ip_len = 2 * MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen;
#ifdef RAW_OUTPUT_IS_RAW
ip->ip_len = htons(ip->ip_len);
#endif
bzero(&sdst, sizeof(sdst));
sdst.sin_family = AF_INET;
#ifdef HAVE_SA_LEN
sdst.sin_len = sizeof(sdst);
#endif
sdst.sin_addr = ip->ip_dst;
iov[0].iov_base = (caddr_t)v->uv_encap_hdr;
iov[0].iov_len = sizeof(struct ip);
iov[1].iov_base = (caddr_t)send_buf;
iov[1].iov_len = MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen;
bzero(&msg, sizeof(msg));
msg.msg_name = (caddr_t)&sdst;
msg.msg_namelen = sizeof(sdst);
msg.msg_iov = iov;
msg.msg_iovlen = 2;
if (sendmsg(raw_socket, &msg, 0) < 0) {
if (errno == ENETDOWN)
check_vif_state();
else
log(LOG_WARNING, errno,
"sendmsg to %s on %s",
inet_fmt(sdst.sin_addr.s_addr, s1), inet_fmt(src, s2));
}
IF_DEBUG(DEBUG_PKT|igmp_debug_kind(type, code))
log(LOG_DEBUG, 0, "SENT %s from %-15s to %s encaped to %s",
igmp_packet_kind(type, code), src == INADDR_ANY ? "INADDR_ANY" :
inet_fmt(src, s1), inet_fmt(dst, s2),
inet_fmt(sdst.sin_addr.s_addr, s3));
}