[thirdparty/bird.git] / sysdep / linux / sysio.h

/*
 *	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);
}

/*
 *  Multicasting in Linux systems is a real mess. Not only different kernels
 *  have different interfaces, but also different libc's export it in different
 *  ways. Horrible.
 */


#if defined(CONFIG_LINUX_MC_MREQ) || defined(CONFIG_LINUX_MC_MREQ_BIND)
/*
 *  Older kernels support only struct mreq which matches interfaces by their
 *  addresses and thus fails on unnumbered devices. On newer 2.0 kernels
 *  we can use SO_BINDTODEVICE to circumvent this problem.
 */

#define MREQ_IFA struct in_addr
#define MREQ_GRP struct ip_mreq
static inline void fill_mreq_ifa(struct in_addr *m, struct iface *ifa UNUSED, ip_addr saddr, ip_addr maddr UNUSED)
{
  set_inaddr(m, saddr);
}

static inline void fill_mreq_grp(struct ip_mreq *m, struct iface *ifa, ip_addr saddr, ip_addr maddr)
{
  bzero(m, sizeof(*m));
#ifdef CONFIG_LINUX_MC_MREQ_BIND
  m->imr_interface.s_addr = INADDR_ANY;
#else
  set_inaddr(&m->imr_interface, saddr);
#endif
  set_inaddr(&m->imr_multiaddr, maddr);
}
#endif


#ifdef CONFIG_LINUX_MC_MREQN
/*
 *  2.1 and newer kernels use struct mreqn which passes ifindex, so no
 *  problems with unnumbered devices.
 */

#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

#define MREQ_IFA struct ip_mreqn
#define MREQ_GRP struct ip_mreqn
#define fill_mreq_ifa fill_mreq
#define fill_mreq_grp fill_mreq

static inline void fill_mreq(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);
}
#endif

static inline char *
sysio_setup_multicast(sock *s)
{
  MREQ_IFA 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_mreq_ifa(&m, s->iface, s->saddr, IPA_NONE);
  if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &m, sizeof(m)) < 0)
    return "IP_MULTICAST_IF";

#if defined(CONFIG_LINUX_MC_MREQ_BIND) || defined(CONFIG_LINUX_MC_MREQN) 
  {
    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";
  }
#endif

  return NULL;
}

static inline char *
sysio_join_group(sock *s, ip_addr maddr)
{
  MREQ_GRP m;

  /* And this one sets interface for _receiving_ multicasts from */
  fill_mreq_grp(&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)
{
  MREQ_GRP m;

  /* And this one sets interface for _receiving_ multicasts from */
  fill_mreq_grp(&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))
#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";

  return NULL;
}

static void
sysio_process_rx_cmsgs(sock *s, struct msghdr *msg)
{
  struct cmsghdr *cm;
  struct in_pktinfo *pi = NULL;

  if (!(s->flags & SKF_LADDR_RX))
    return;

  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 (!pi)
    {
      s->laddr = IPA_NONE;
      s->lifindex = 0;
      return;
    }

  get_inaddr(&s->laddr, &pi->ipi_addr);
  s->lifindex = pi->ipi_ifindex;
  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_ttl4: setsockopt: %m");

    return -1;
  }

  return 0;
}

#endif
Commit	Line	Data
67ece6df MM	1	/*
	2	* BIRD Internet Routing Daemon -- Linux Multicasting and Network Includes
	3	*
f380aa60	4	* (c) 1998--2000 Martin Mares <mj@ucw.cz>
67ece6df MM	5	*
	6	* Can be freely distributed and used under the terms of the GNU GPL.
	7	*/
	8
e7b09e4a OZ	9	#include <net/if.h>
e7b09e4a OZ	10
67ece6df	11	#ifdef IPV6
a2867cd9	12
84f07002 MM	13	#ifndef IPV6_UNICAST_HOPS
84f07002 MM	14	/* Needed on glibc 2.0 systems */
f380aa60	15	#include <linux/in6.h>
84f07002	16	#define CONFIG_IPV6_GLIBC_20
f380aa60	17	#endif
67ece6df	18
a2867cd9 MM	19	static inline void
	20	set_inaddr(struct in6_addr *ia, ip_addr a)
	21	{
	22	ipa_hton(a);
	23	memcpy(ia, &a, sizeof(a));
	24	}
	25
353729f5 OZ	26	static inline void
	27	get_inaddr(ip_addr a, struct in6_addr ia)
	28	{
	29	memcpy(a, ia, sizeof(*a));
	30	ipa_ntoh(*a);
	31	}
	32
e7b09e4a OZ	33	static inline char *
	34	sysio_bind_to_iface(sock *s)
	35	{
	36	struct ifreq ifr;
	37	strcpy(ifr.ifr_name, s->iface->name);
	38	if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
	39	return "SO_BINDTODEVICE";
67ece6df	40
e7b09e4a OZ	41	return NULL;
	42	}
	43
	44	#else
0e5aa966	45
a2867cd9 MM	46	static inline void
	47	set_inaddr(struct in_addr *ia, ip_addr a)
	48	{
	49	ipa_hton(a);
	50	memcpy(&ia->s_addr, &a, sizeof(a));
	51	}
	52
353729f5 OZ	53	static inline void
	54	get_inaddr(ip_addr a, struct in_addr ia)
	55	{
	56	memcpy(a, &ia->s_addr, sizeof(*a));
	57	ipa_ntoh(*a);
	58	}
	59
67ece6df MM	60	/*
	61	* Multicasting in Linux systems is a real mess. Not only different kernels
	62	* have different interfaces, but also different libc's export it in different
	63	* ways. Horrible.
	64	*/
	65
f9c799a0 OZ	66
	67	#if defined(CONFIG_LINUX_MC_MREQ) \|\| defined(CONFIG_LINUX_MC_MREQ_BIND)
	68	/*
	69	* Older kernels support only struct mreq which matches interfaces by their
	70	* addresses and thus fails on unnumbered devices. On newer 2.0 kernels
	71	* we can use SO_BINDTODEVICE to circumvent this problem.
	72	*/
	73
	74	#define MREQ_IFA struct in_addr
	75	#define MREQ_GRP struct ip_mreq
0aad2b92	76	static inline void fill_mreq_ifa(struct in_addr m, struct iface ifa UNUSED, ip_addr saddr, ip_addr maddr UNUSED)
67ece6df	77	{
0aad2b92	78	set_inaddr(m, saddr);
f9c799a0	79	}
67ece6df	80
0aad2b92	81	static inline void fill_mreq_grp(struct ip_mreq m, struct iface ifa, ip_addr saddr, ip_addr maddr)
f9c799a0 OZ	82	{
	83	bzero(m, sizeof(*m));
	84	#ifdef CONFIG_LINUX_MC_MREQ_BIND
	85	m->imr_interface.s_addr = INADDR_ANY;
	86	#else
0aad2b92	87	set_inaddr(&m->imr_interface, saddr);
67ece6df	88	#endif
f9c799a0	89	set_inaddr(&m->imr_multiaddr, maddr);
67ece6df	90	}
f9c799a0 OZ	91	#endif
f9c799a0 OZ	92
67ece6df MM	93
	94	#ifdef CONFIG_LINUX_MC_MREQN
	95	/*
	96	* 2.1 and newer kernels use struct mreqn which passes ifindex, so no
	97	* problems with unnumbered devices.
	98	*/
	99
	100	#ifndef HAVE_STRUCT_IP_MREQN
	101	/* Several versions of glibc don't define this structure, so we have to do it ourselves */
	102	struct ip_mreqn
	103	{
	104	struct in_addr imr_multiaddr; /* IP multicast address of group */
	105	struct in_addr imr_address; /* local IP address of interface */
	106	int imr_ifindex; /* Interface index */
	107	};
	108	#endif
	109
f9c799a0 OZ	110	#define MREQ_IFA struct ip_mreqn
	111	#define MREQ_GRP struct ip_mreqn
	112	#define fill_mreq_ifa fill_mreq
	113	#define fill_mreq_grp fill_mreq
	114
0aad2b92	115	static inline void fill_mreq(struct ip_mreqn m, struct iface ifa, ip_addr saddr, ip_addr maddr)
67ece6df	116	{
f9c799a0 OZ	117	bzero(m, sizeof(*m));
f9c799a0 OZ	118	m->imr_ifindex = ifa->index;
0aad2b92	119	set_inaddr(&m->imr_address, saddr);
f9c799a0	120	set_inaddr(&m->imr_multiaddr, maddr);
67ece6df MM	121	}
	122	#endif
	123
f9c799a0 OZ	124	static inline char *
f9c799a0 OZ	125	sysio_setup_multicast(sock *s)
67ece6df	126	{
f9c799a0 OZ	127	MREQ_IFA m;
f9c799a0 OZ	128	int zero = 0;
67ece6df	129
f9c799a0 OZ	130	if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_LOOP, &zero, sizeof(zero)) < 0)
	131	return "IP_MULTICAST_LOOP";
	132
	133	if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_TTL, &s->ttl, sizeof(s->ttl)) < 0)
	134	return "IP_MULTICAST_TTL";
	135
	136	/* This defines where should we send _outgoing_ multicasts */
0aad2b92	137	fill_mreq_ifa(&m, s->iface, s->saddr, IPA_NONE);
f9c799a0 OZ	138	if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &m, sizeof(m)) < 0)
	139	return "IP_MULTICAST_IF";
	140
	141	#if defined(CONFIG_LINUX_MC_MREQ_BIND) \|\| defined(CONFIG_LINUX_MC_MREQN)
67ece6df MM	142	{
	143	struct ifreq ifr;
	144	strcpy(ifr.ifr_name, s->iface->name);
	145	if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
	146	return "SO_BINDTODEVICE";
67ece6df	147	}
67ece6df	148	#endif
f9c799a0 OZ	149
	150	return NULL;
	151	}
	152
	153	static inline char *
	154	sysio_join_group(sock *s, ip_addr maddr)
	155	{
	156	MREQ_GRP m;
	157
67ece6df	158	/* And this one sets interface for _receiving_ multicasts from */
0aad2b92	159	fill_mreq_grp(&m, s->iface, s->saddr, maddr);
f9c799a0	160	if (setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &m, sizeof(m)) < 0)
67ece6df	161	return "IP_ADD_MEMBERSHIP";
f9c799a0 OZ	162
	163	return NULL;
	164	}
	165
	166	static inline char *
	167	sysio_leave_group(sock *s, ip_addr maddr)
	168	{
	169	MREQ_GRP m;
	170
	171	/* And this one sets interface for _receiving_ multicasts from */
0aad2b92	172	fill_mreq_grp(&m, s->iface, s->saddr, maddr);
f9c799a0 OZ	173	if (setsockopt(s->fd, SOL_IP, IP_DROP_MEMBERSHIP, &m, sizeof(m)) < 0)
	174	return "IP_DROP_MEMBERSHIP";
	175
67ece6df MM	176	return NULL;
67ece6df MM	177	}
67ece6df MM	178
67ece6df MM	179	#endif
d51aa281	180
f9c799a0	181
d51aa281 OZ	182	#include <linux/socket.h>
	183	#include <linux/tcp.h>
	184
	185	/* For the case that we have older kernel headers */
	186	/* Copied from Linux kernel file include/linux/tcp.h */
	187
	188	#ifndef TCP_MD5SIG
	189
	190	#define TCP_MD5SIG 14
	191	#define TCP_MD5SIG_MAXKEYLEN 80
	192
	193	struct tcp_md5sig {
11ec0f1a	194	struct sockaddr_storage tcpm_addr; /* address associated */
d51aa281 OZ	195	__u16 __tcpm_pad1; /* zero */
	196	__u16 tcpm_keylen; /* key length */
	197	__u32 __tcpm_pad2; /* zero */
	198	__u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
	199	};
	200
	201	#endif
2b70f074 OF	202
	203	static int
	204	sk_set_md5_auth_int(sock s, sockaddr sa, char *passwd)
	205	{
	206	struct tcp_md5sig md5;
	207
	208	memset(&md5, 0, sizeof(md5));
	209	memcpy(&md5.tcpm_addr, (struct sockaddr ) sa, sizeof(sa));
	210
	211	if (passwd)
	212	{
	213	int len = strlen(passwd);
	214
	215	if (len > TCP_MD5SIG_MAXKEYLEN)
	216	{
	217	log(L_ERR "MD5 password too long");
	218	return -1;
	219	}
	220
	221	md5.tcpm_keylen = len;
	222	memcpy(&md5.tcpm_key, passwd, len);
	223	}
	224
	225	int rv = setsockopt(s->fd, IPPROTO_TCP, TCP_MD5SIG, &md5, sizeof(md5));
	226
	227	if (rv < 0)
	228	{
	229	if (errno == ENOPROTOOPT)
	230	log(L_ERR "Kernel does not support TCP MD5 signatures");
	231	else
	232	log(L_ERR "sk_set_md5_auth_int: setsockopt: %m");
	233	}
	234
	235	return rv;
	236	}
353729f5 OZ	237
	238
	239	#ifndef IPV6
	240
	241	/* RX/TX packet info handling for IPv4 */
	242	/* Mostly similar to standardized IPv6 code */
	243
	244	#define CMSG_RX_SPACE CMSG_SPACE(sizeof(struct in_pktinfo))
	245	#define CMSG_TX_SPACE CMSG_SPACE(sizeof(struct in_pktinfo))
	246
	247	static char *
	248	sysio_register_cmsgs(sock *s)
	249	{
	250	int ok = 1;
	251	if ((s->flags & SKF_LADDR_RX) &&
	252	setsockopt(s->fd, IPPROTO_IP, IP_PKTINFO, &ok, sizeof(ok)) < 0)
	253	return "IP_PKTINFO";
	254
	255	return NULL;
	256	}
	257
	258	static void
	259	sysio_process_rx_cmsgs(sock s, struct msghdr msg)
	260	{
	261	struct cmsghdr *cm;
	262	struct in_pktinfo *pi = NULL;
	263
	264	if (!(s->flags & SKF_LADDR_RX))
	265	return;
	266
	267	for (cm = CMSG_FIRSTHDR(msg); cm != NULL; cm = CMSG_NXTHDR(msg, cm))
	268	{
	269	if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_PKTINFO)
	270	pi = (struct in_pktinfo *) CMSG_DATA(cm);
	271	}
	272
	273	if (!pi)
	274	{
	275	s->laddr = IPA_NONE;
	276	s->lifindex = 0;
	277	return;
	278	}
	279
	280	get_inaddr(&s->laddr, &pi->ipi_addr);
	281	s->lifindex = pi->ipi_ifindex;
	282	return;
	283	}
	284
646b24d9	285	/*
bed41728 OZ	286	static void
bed41728 OZ	287	sysio_prepare_tx_cmsgs(sock s, struct msghdr msg, void *cbuf, size_t cbuflen)
353729f5 OZ	288	{
	289	struct cmsghdr *cm;
	290	struct in_pktinfo *pi;
	291
	292	if (!(s->flags & SKF_LADDR_TX))
bed41728 OZ	293	return;
	294
	295	msg->msg_control = cbuf;
	296	msg->msg_controllen = cbuflen;
353729f5 OZ	297
	298	cm = CMSG_FIRSTHDR(msg);
	299	cm->cmsg_level = IPPROTO_IP;
	300	cm->cmsg_type = IP_PKTINFO;
	301	cm->cmsg_len = CMSG_LEN(sizeof(*pi));
	302
	303	pi = (struct in_pktinfo *) CMSG_DATA(cm);
	304	set_inaddr(&pi->ipi_spec_dst, s->saddr);
	305	pi->ipi_ifindex = s->iface ? s->iface->index : 0;
	306
	307	msg->msg_controllen = cm->cmsg_len;
	308	}
646b24d9 OZ	309	*/
646b24d9 OZ	310
353729f5	311	#endif
b1b19433 OZ	312
	313
	314	#ifndef IP_MINTTL
	315	#define IP_MINTTL 21
	316	#endif
	317
	318	#ifndef IPV6_MINHOPCOUNT
	319	#define IPV6_MINHOPCOUNT 73
	320	#endif
	321
	322
	323	#ifndef IPV6
	324
	325	static int
	326	sk_set_min_ttl4(sock *s, int ttl)
	327	{
	328	if (setsockopt(s->fd, IPPROTO_IP, IP_MINTTL, &ttl, sizeof(ttl)) < 0)
	329	{
	330	if (errno == ENOPROTOOPT)
	331	log(L_ERR "Kernel does not support IPv4 TTL security");
	332	else
	333	log(L_ERR "sk_set_min_ttl4: setsockopt: %m");
	334
	335	return -1;
	336	}
	337
	338	return 0;
	339	}
	340
	341	#else
	342
	343	static int
	344	sk_set_min_ttl6(sock *s, int ttl)
	345	{
	346	if (setsockopt(s->fd, IPPROTO_IPV6, IPV6_MINHOPCOUNT, &ttl, sizeof(ttl)) < 0)
	347	{
	348	if (errno == ENOPROTOOPT)
	349	log(L_ERR "Kernel does not support IPv6 TTL security");
	350	else
	351	log(L_ERR "sk_set_min_ttl4: setsockopt: %m");
	352
	353	return -1;
	354	}
	355
	356	return 0;
	357	}
	358
	359	#endif