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bird/sysdep/linux/sysio.h
Ondrej Zajicek 70e212f913 Implements TTL security for OSPF and RIP.
Interfaces for OSPF and RIP could be configured to use (and request)
TTL 255 for traffic to direct neighbors.

Thanks to Simon Dickhoven for the original patch for RIPng.
2013-06-25 15:39:44 +02:00

346 lines
7.1 KiB
C

/*
* BIRD Internet Routing Daemon -- Linux Multicasting and Network Includes
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <net/if.h>
#ifdef IPV6
#ifndef IPV6_UNICAST_HOPS
/* Needed on glibc 2.0 systems */
#include <linux/in6.h>
#define CONFIG_IPV6_GLIBC_20
#endif
static inline void
set_inaddr(struct in6_addr *ia, ip_addr a)
{
ipa_hton(a);
memcpy(ia, &a, sizeof(a));
}
static inline void
get_inaddr(ip_addr *a, struct in6_addr *ia)
{
memcpy(a, ia, sizeof(*a));
ipa_ntoh(*a);
}
static inline char *
sysio_bind_to_iface(sock *s)
{
struct ifreq ifr;
strcpy(ifr.ifr_name, s->iface->name);
if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
return "SO_BINDTODEVICE";
return NULL;
}
#else
static inline void
set_inaddr(struct in_addr *ia, ip_addr a)
{
ipa_hton(a);
memcpy(&ia->s_addr, &a, sizeof(a));
}
static inline void
get_inaddr(ip_addr *a, struct in_addr *ia)
{
memcpy(a, &ia->s_addr, sizeof(*a));
ipa_ntoh(*a);
}
#ifndef HAVE_STRUCT_IP_MREQN
/* Several versions of glibc don't define this structure, so we have to do it ourselves */
struct ip_mreqn
{
struct in_addr imr_multiaddr; /* IP multicast address of group */
struct in_addr imr_address; /* local IP address of interface */
int imr_ifindex; /* Interface index */
};
#endif
static inline void fill_mreqn(struct ip_mreqn *m, struct iface *ifa, ip_addr saddr, ip_addr maddr)
{
bzero(m, sizeof(*m));
m->imr_ifindex = ifa->index;
set_inaddr(&m->imr_address, saddr);
set_inaddr(&m->imr_multiaddr, maddr);
}
static inline char *
sysio_setup_multicast(sock *s)
{
struct ip_mreqn m;
int zero = 0;
if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_LOOP, &zero, sizeof(zero)) < 0)
return "IP_MULTICAST_LOOP";
if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_TTL, &s->ttl, sizeof(s->ttl)) < 0)
return "IP_MULTICAST_TTL";
/* This defines where should we send _outgoing_ multicasts */
fill_mreqn(&m, s->iface, s->saddr, IPA_NONE);
if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &m, sizeof(m)) < 0)
return "IP_MULTICAST_IF";
/* Is this necessary? */
struct ifreq ifr;
strcpy(ifr.ifr_name, s->iface->name);
if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
return "SO_BINDTODEVICE";
return NULL;
}
static inline char *
sysio_join_group(sock *s, ip_addr maddr)
{
struct ip_mreqn m;
/* And this one sets interface for _receiving_ multicasts from */
fill_mreqn(&m, s->iface, s->saddr, maddr);
if (setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &m, sizeof(m)) < 0)
return "IP_ADD_MEMBERSHIP";
return NULL;
}
static inline char *
sysio_leave_group(sock *s, ip_addr maddr)
{
struct ip_mreqn m;
/* And this one sets interface for _receiving_ multicasts from */
fill_mreqn(&m, s->iface, s->saddr, maddr);
if (setsockopt(s->fd, SOL_IP, IP_DROP_MEMBERSHIP, &m, sizeof(m)) < 0)
return "IP_DROP_MEMBERSHIP";
return NULL;
}
#endif
#include <linux/socket.h>
#include <linux/tcp.h>
/* For the case that we have older kernel headers */
/* Copied from Linux kernel file include/linux/tcp.h */
#ifndef TCP_MD5SIG
#define TCP_MD5SIG 14
#define TCP_MD5SIG_MAXKEYLEN 80
struct tcp_md5sig {
struct sockaddr_storage tcpm_addr; /* address associated */
__u16 __tcpm_pad1; /* zero */
__u16 tcpm_keylen; /* key length */
__u32 __tcpm_pad2; /* zero */
__u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
};
#endif
static int
sk_set_md5_auth_int(sock *s, sockaddr *sa, char *passwd)
{
struct tcp_md5sig md5;
memset(&md5, 0, sizeof(md5));
memcpy(&md5.tcpm_addr, (struct sockaddr *) sa, sizeof(*sa));
if (passwd)
{
int len = strlen(passwd);
if (len > TCP_MD5SIG_MAXKEYLEN)
{
log(L_ERR "MD5 password too long");
return -1;
}
md5.tcpm_keylen = len;
memcpy(&md5.tcpm_key, passwd, len);
}
int rv = setsockopt(s->fd, IPPROTO_TCP, TCP_MD5SIG, &md5, sizeof(md5));
if (rv < 0)
{
if (errno == ENOPROTOOPT)
log(L_ERR "Kernel does not support TCP MD5 signatures");
else
log(L_ERR "sk_set_md5_auth_int: setsockopt: %m");
}
return rv;
}
#ifndef IPV6
/* RX/TX packet info handling for IPv4 */
/* Mostly similar to standardized IPv6 code */
#define CMSG_RX_SPACE (CMSG_SPACE(sizeof(struct in_pktinfo)) + CMSG_SPACE(sizeof(int)))
#define CMSG_TX_SPACE CMSG_SPACE(sizeof(struct in_pktinfo))
static char *
sysio_register_cmsgs(sock *s)
{
int ok = 1;
if ((s->flags & SKF_LADDR_RX) &&
(setsockopt(s->fd, IPPROTO_IP, IP_PKTINFO, &ok, sizeof(ok)) < 0))
return "IP_PKTINFO";
if ((s->flags & SKF_TTL_RX) &&
(setsockopt(s->fd, IPPROTO_IP, IP_RECVTTL, &ok, sizeof(ok)) < 0))
return "IP_RECVTTL";
return NULL;
}
static void
sysio_process_rx_cmsgs(sock *s, struct msghdr *msg)
{
struct cmsghdr *cm;
struct in_pktinfo *pi = NULL;
int *ttl = NULL;
for (cm = CMSG_FIRSTHDR(msg); cm != NULL; cm = CMSG_NXTHDR(msg, cm))
{
if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_PKTINFO)
pi = (struct in_pktinfo *) CMSG_DATA(cm);
if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_TTL)
ttl = (int *) CMSG_DATA(cm);
}
if (s->flags & SKF_LADDR_RX)
{
if (pi)
{
get_inaddr(&s->laddr, &pi->ipi_addr);
s->lifindex = pi->ipi_ifindex;
}
else
{
s->laddr = IPA_NONE;
s->lifindex = 0;
}
}
if (s->flags & SKF_TTL_RX)
s->ttl = ttl ? *ttl : -1;
return;
}
/*
static void
sysio_prepare_tx_cmsgs(sock *s, struct msghdr *msg, void *cbuf, size_t cbuflen)
{
struct cmsghdr *cm;
struct in_pktinfo *pi;
if (!(s->flags & SKF_LADDR_TX))
return;
msg->msg_control = cbuf;
msg->msg_controllen = cbuflen;
cm = CMSG_FIRSTHDR(msg);
cm->cmsg_level = IPPROTO_IP;
cm->cmsg_type = IP_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(*pi));
pi = (struct in_pktinfo *) CMSG_DATA(cm);
set_inaddr(&pi->ipi_spec_dst, s->saddr);
pi->ipi_ifindex = s->iface ? s->iface->index : 0;
msg->msg_controllen = cm->cmsg_len;
}
*/
#endif
#ifndef IP_MINTTL
#define IP_MINTTL 21
#endif
#ifndef IPV6_MINHOPCOUNT
#define IPV6_MINHOPCOUNT 73
#endif
#ifndef IPV6
static int
sk_set_min_ttl4(sock *s, int ttl)
{
if (setsockopt(s->fd, IPPROTO_IP, IP_MINTTL, &ttl, sizeof(ttl)) < 0)
{
if (errno == ENOPROTOOPT)
log(L_ERR "Kernel does not support IPv4 TTL security");
else
log(L_ERR "sk_set_min_ttl4: setsockopt: %m");
return -1;
}
return 0;
}
#else
static int
sk_set_min_ttl6(sock *s, int ttl)
{
if (setsockopt(s->fd, IPPROTO_IPV6, IPV6_MINHOPCOUNT, &ttl, sizeof(ttl)) < 0)
{
if (errno == ENOPROTOOPT)
log(L_ERR "Kernel does not support IPv6 TTL security");
else
log(L_ERR "sk_set_min_ttl6: setsockopt: %m");
return -1;
}
return 0;
}
#endif
#ifndef IPV6_TCLASS
#define IPV6_TCLASS 67
#endif
int sk_priority_control = 7;
static int
sk_set_priority(sock *s, int prio)
{
if (setsockopt(s->fd, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio)) < 0)
{
log(L_WARN "sk_set_priority: setsockopt: %m");
return -1;
}
return 0;
}