Adding upstream version 1:2.3.19.1+dfsg1.upstream/1%2.3.19.1+dfsg1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1237 insertions, 0 deletions

diff --git a/src/lib/net.c b/src/lib/net.c
new file mode 100644
index 0000000..fe69faf
--- /dev/null
+++ b/src/lib/net.c
@@ -0,0 +1,1237 @@
+/* Copyright (c) 1999-2018 Dovecot authors, see the included COPYING file */
+
+#define _GNU_SOURCE /* For Linux's struct ucred */
+#include "lib.h"
+#include "time-util.h"
+#include "net.h"
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <sys/un.h>
+#include <netinet/tcp.h>
+#if defined(HAVE_UCRED_H)
+#  include <ucred.h> /* for getpeerucred() */
+#elif defined(HAVE_SYS_UCRED_H)
+#  include <sys/ucred.h> /* for FreeBSD struct xucred */
+#endif
+
+union sockaddr_union {
+	struct sockaddr sa;
+	struct sockaddr_in sin;
+	struct sockaddr_in6 sin6;
+};
+
+union sockaddr_union_unix {
+	struct sockaddr sa;
+	struct sockaddr_un un;
+};
+
+#define SIZEOF_SOCKADDR(so) ((so).sa.sa_family == AF_INET6 ? \
+	sizeof(so.sin6) : sizeof(so.sin))
+
+#if !defined(HAVE_GETPEEREID) && !defined(SO_PEERCRED) && !defined(HAVE_GETPEERUCRED) && defined(MSG_WAITALL) && defined(LOCAL_CREDS)
+#  define NEEDS_LOCAL_CREDS 1
+#else
+#  undef NEEDS_LOCAL_CREDS
+#endif
+
+/* If connect() fails with EADDRNOTAVAIL (or some others on FreeBSD), retry it
+   this many times.
+
+   This is needed on busy systems kernel may assign the same source port to two
+   sockets at bind() stage, which is what we generally want to allow more than
+   64k outgoing connections to different destinations. However, at bind() stage
+   the kernel doesn't know the destination yet. So it's possible that it
+   assigns the same source port to two (or more) sockets that have the same
+   destination IP+port as well. In this case connect() will fail with
+   EADDRNOTAVAIL. We'll need to retry this and hope that the next attempt won't
+   conflict. */
+#define MAX_CONNECT_RETRIES 20
+
+bool net_ip_compare(const struct ip_addr *ip1, const struct ip_addr *ip2)
+{
+	return net_ip_cmp(ip1, ip2) == 0;
+}
+
+int net_ip_cmp(const struct ip_addr *ip1, const struct ip_addr *ip2)
+{
+	if (ip1->family != ip2->family)
+		return ip1->family - ip2->family;
+
+	switch (ip1->family) {
+	case AF_INET6:
+		return memcmp(&ip1->u.ip6, &ip2->u.ip6, sizeof(ip1->u.ip6));
+	case AF_INET:
+		return memcmp(&ip1->u.ip4, &ip2->u.ip4, sizeof(ip1->u.ip4));
+	default:
+		break;
+	}
+	return 0;
+}
+
+unsigned int net_ip_hash(const struct ip_addr *ip)
+{
+        const unsigned char *p;
+	unsigned int len, g, h = 0;
+
+	if (ip->family == AF_INET6) {
+		p = ip->u.ip6.s6_addr;
+		len = sizeof(ip->u.ip6);
+	} else
+	{
+		return ip->u.ip4.s_addr;
+	}
+
+	for (; len > 0; len--, p++) {
+		h = (h << 4) + *p;
+		if ((g = h & 0xf0000000UL) != 0) {
+			h = h ^ (g >> 24);
+			h = h ^ g;
+		}
+	}
+
+	return h;
+}
+
+/* copy IP to sockaddr */
+static inline void
+sin_set_ip(union sockaddr_union *so, const struct ip_addr *ip)
+{
+	if (ip == NULL) {
+		so->sin6.sin6_family = AF_INET6;
+		so->sin6.sin6_addr = in6addr_any;
+		return;
+	}
+
+	so->sin.sin_family = ip->family;
+	if (ip->family == AF_INET6)
+		memcpy(&so->sin6.sin6_addr, &ip->u.ip6, sizeof(ip->u.ip6));
+	else
+		memcpy(&so->sin.sin_addr, &ip->u.ip4, sizeof(ip->u.ip4));
+}
+
+static inline void
+sin_get_ip(const union sockaddr_union *so, struct ip_addr *ip)
+{
+	/* IP structs may be sent across processes. Clear the whole struct
+	   first to make sure it won't leak any data across processes. */
+	i_zero(ip);
+
+	ip->family = so->sin.sin_family;
+
+	if (ip->family == AF_INET6)
+		memcpy(&ip->u.ip6, &so->sin6.sin6_addr, sizeof(ip->u.ip6));
+	else
+	if (ip->family == AF_INET)
+		memcpy(&ip->u.ip4, &so->sin.sin_addr, sizeof(ip->u.ip4));
+	else
+		i_zero(&ip->u);
+}
+
+static inline void sin_set_port(union sockaddr_union *so, in_port_t port)
+{
+	if (so->sin.sin_family == AF_INET6)
+                so->sin6.sin6_port = htons(port);
+	else
+		so->sin.sin_port = htons(port);
+}
+
+static inline in_port_t sin_get_port(union sockaddr_union *so)
+{
+	if (so->sin.sin_family == AF_INET6)
+		return ntohs(so->sin6.sin6_port);
+	if (so->sin.sin_family == AF_INET)
+		return ntohs(so->sin.sin_port);
+
+	return 0;
+}
+
+static int net_connect_ip_once(const struct ip_addr *ip, in_port_t port,
+			       const struct ip_addr *my_ip, int sock_type, bool blocking)
+{
+	union sockaddr_union so;
+	int fd, ret, opt = 1;
+
+	if (my_ip != NULL && ip->family != my_ip->family) {
+		i_warning("net_connect_ip(): ip->family != my_ip->family");
+                my_ip = NULL;
+	}
+
+	/* create the socket */
+	i_zero(&so);
+        so.sin.sin_family = ip->family;
+	fd = socket(ip->family, sock_type, 0);
+
+	if (fd == -1) {
+		i_error("socket() failed: %m");
+		return -1;
+	}
+
+	/* set socket options */
+	(void)setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+	if (sock_type == SOCK_STREAM)
+		(void)setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &opt, sizeof(opt));
+	if (!blocking)
+		net_set_nonblock(fd, TRUE);
+
+	/* set our own address */
+	if (my_ip != NULL) {
+		sin_set_ip(&so, my_ip);
+		if (bind(fd, &so.sa, SIZEOF_SOCKADDR(so)) == -1) {
+			i_error("bind(%s) failed: %m", net_ip2addr(my_ip));
+			i_close_fd(&fd);
+			return -1;
+		}
+	}
+
+	/* connect */
+	sin_set_ip(&so, ip);
+	sin_set_port(&so, port);
+	ret = connect(fd, &so.sa, SIZEOF_SOCKADDR(so));
+
+#ifndef WIN32
+	if (ret < 0 && errno != EINPROGRESS)
+#else
+	if (ret < 0 && WSAGetLastError() != WSAEWOULDBLOCK)
+#endif
+	{
+                i_close_fd(&fd);
+		return -1;
+	}
+
+	return fd;
+}
+
+static int net_connect_ip_full(const struct ip_addr *ip, in_port_t port,
+			       const struct ip_addr *my_ip, int sock_type,
+			       bool blocking)
+{
+	int fd, try;
+
+	for (try = 0;;) {
+		fd = net_connect_ip_once(ip, port, my_ip, sock_type, blocking);
+		if (fd != -1 || try++ >= MAX_CONNECT_RETRIES ||
+		    (errno != EADDRNOTAVAIL
+#ifdef __FreeBSD__
+		     /* busy */
+		     && errno != EADDRINUSE
+		     /* pf may cause this if another connection used
+			the same port recently */
+		     && errno != EACCES
+#endif
+		    ))
+			break;
+	}
+	return fd;
+}
+
+int net_connect_ip(const struct ip_addr *ip, in_port_t port,
+		   const struct ip_addr *my_ip)
+{
+	return net_connect_ip_full(ip, port, my_ip, SOCK_STREAM, FALSE);
+}
+
+int net_connect_ip_blocking(const struct ip_addr *ip, in_port_t port,
+			    const struct ip_addr *my_ip)
+{
+	return net_connect_ip_full(ip, port, my_ip, SOCK_STREAM, TRUE);
+}
+
+int net_connect_udp(const struct ip_addr *ip, in_port_t port,
+			       const struct ip_addr *my_ip)
+{
+	return net_connect_ip_full(ip, port, my_ip, SOCK_DGRAM, FALSE);
+}
+
+int net_try_bind(const struct ip_addr *ip)
+{
+	union sockaddr_union so;
+	int fd;
+
+	/* create the socket */
+	i_zero(&so);
+        so.sin.sin_family = ip->family;
+	fd = socket(ip->family, SOCK_STREAM, 0);
+	if (fd == -1) {
+		i_error("socket() failed: %m");
+		return -1;
+	}
+
+	sin_set_ip(&so, ip);
+	if (bind(fd, &so.sa, SIZEOF_SOCKADDR(so)) == -1) {
+		i_close_fd(&fd);
+		return -1;
+	}
+	i_close_fd(&fd);
+	return 0;
+}
+
+int net_connect_unix(const char *path)
+{
+	union sockaddr_union_unix sa;
+	int fd, ret;
+
+	i_zero(&sa);
+	sa.un.sun_family = AF_UNIX;
+	if (i_strocpy(sa.un.sun_path, path, sizeof(sa.un.sun_path)) < 0) {
+		/* too long path */
+#ifdef ENAMETOOLONG
+		errno = ENAMETOOLONG;
+#else
+		errno = EOVERFLOW;
+#endif
+		return -1;
+	}
+
+	/* create the socket */
+	fd = socket(PF_UNIX, SOCK_STREAM, 0);
+	if (fd == -1) {
+		i_error("socket(%s) failed: %m", path);
+		return -1;
+	}
+
+	net_set_nonblock(fd, TRUE);
+
+	/* connect */
+	ret = connect(fd, &sa.sa, sizeof(sa));
+	if (ret < 0 && errno != EINPROGRESS) {
+                i_close_fd(&fd);
+		return -1;
+	}
+
+#ifdef NEEDS_LOCAL_CREDS
+	{
+		int on = 1;
+		if (setsockopt(fd, 0, LOCAL_CREDS, &on, sizeof on)) {
+			i_error("setsockopt(LOCAL_CREDS) failed: %m");
+			return -1;
+		}
+	}
+#endif
+
+	return fd;
+}
+
+int net_connect_unix_with_retries(const char *path, unsigned int msecs)
+{
+	struct timeval start, now;
+	int fd;
+
+	i_gettimeofday(&start);
+
+	do {
+		fd = net_connect_unix(path);
+		if (fd != -1 || (errno != EAGAIN && errno != ECONNREFUSED))
+			break;
+
+		/* busy. wait for a while. */
+		usleep(i_rand_minmax(1, 10) * 10000);
+		i_gettimeofday(&now);
+	} while (timeval_diff_msecs(&now, &start) < (int)msecs);
+	return fd;
+}
+
+void net_disconnect(int fd)
+{
+	/* FreeBSD's close() fails with ECONNRESET if socket still has unsent
+	   data in transmit buffer. We don't care. */
+	if (close(fd) < 0 && errno != ECONNRESET)
+		i_error("net_disconnect() failed: %m");
+}
+
+void net_set_nonblock(int fd, bool nonblock)
+{
+	fd_set_nonblock(fd, nonblock);
+}
+
+int net_set_cork(int fd ATTR_UNUSED, bool cork ATTR_UNUSED)
+{
+#ifdef TCP_CORK
+	int val = cork;
+
+	return setsockopt(fd, IPPROTO_TCP, TCP_CORK, &val, sizeof(val));
+#else
+	errno = ENOPROTOOPT;
+	return -1;
+#endif
+}
+
+int net_set_tcp_nodelay(int fd, bool nodelay)
+{
+	int val = nodelay;
+
+	return setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof(val));
+}
+
+int net_set_tcp_quickack(int fd ATTR_UNUSED, bool quickack ATTR_UNUSED)
+{
+#ifdef TCP_QUICKACK
+	int val = quickack;
+
+	return setsockopt(fd, IPPROTO_TCP, TCP_QUICKACK, &val, sizeof(val));
+#else
+	errno = ENOPROTOOPT;
+	return -1;
+#endif
+}
+
+int net_set_send_buffer_size(int fd, size_t size)
+{
+	int opt;
+
+	if (size > INT_MAX) {
+		errno = EINVAL;
+		return -1;
+	}
+	opt = (int)size;
+	return setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt));
+}
+
+int net_set_recv_buffer_size(int fd, size_t size)
+{
+	int opt;
+
+	if (size > INT_MAX) {
+		errno = EINVAL;
+		return -1;
+	}
+	opt = (int)size;
+	return setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt));
+}
+
+const struct ip_addr net_ip4_any = {
+	.family = AF_INET,
+	.u.ip4.s_addr = INADDR_ANY
+};
+
+const struct ip_addr net_ip6_any = {
+	.family = AF_INET6,
+	.u.ip6 = IN6ADDR_ANY_INIT
+};
+
+const struct ip_addr net_ip4_loopback = {
+	.family = AF_INET,
+	.u.ip4.s_addr = INADDR_LOOPBACK
+};
+
+const struct ip_addr net_ip6_loopback = {
+	.family = AF_INET6,
+	.u.ip6 = IN6ADDR_LOOPBACK_INIT
+};
+
+int net_listen(const struct ip_addr *my_ip, in_port_t *port, int backlog)
+{
+	enum net_listen_flags flags = 0;
+
+	return net_listen_full(my_ip, port, &flags, backlog);
+}
+
+int net_listen_full(const struct ip_addr *my_ip, in_port_t *port,
+		    enum net_listen_flags *flags, int backlog)
+{
+	union sockaddr_union so;
+	int ret, fd, opt = 1;
+	socklen_t len;
+
+	i_zero(&so);
+	sin_set_port(&so, *port);
+	sin_set_ip(&so, my_ip);
+
+	/* create the socket */
+	fd = socket(so.sin.sin_family, SOCK_STREAM, 0);
+	if (fd == -1 && my_ip == NULL &&
+	    (errno == EINVAL || errno == EAFNOSUPPORT)) {
+		/* IPv6 is not supported by OS */
+		so.sin.sin_family = AF_INET;
+		so.sin.sin_addr.s_addr = INADDR_ANY;
+
+		fd = socket(AF_INET, SOCK_STREAM, 0);
+	}
+	if (fd == -1) {
+		i_error("socket() failed: %m");
+		return -1;
+	}
+
+	/* set socket options */
+	(void)setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+	(void)setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &opt, sizeof(opt));
+
+	if ((*flags & NET_LISTEN_FLAG_REUSEPORT) != 0) {
+#ifdef SO_REUSEPORT
+		if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT,
+			       &opt, sizeof(opt)) < 0)
+#endif
+			*flags &= ENUM_NEGATE(NET_LISTEN_FLAG_REUSEPORT);
+	}
+
+	/* If using IPv6, bind only to IPv6 if possible. This avoids
+	   ambiguities with IPv4-mapped IPv6 addresses. */
+#ifdef IPV6_V6ONLY
+	if (so.sin.sin_family == AF_INET6) {
+		opt = 1;
+		(void)setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof(opt));
+	}
+#endif
+	/* specify the address/port we want to listen in */
+	ret = bind(fd, &so.sa, SIZEOF_SOCKADDR(so));
+	if (ret < 0) {
+		if (errno != EADDRINUSE) {
+			i_error("bind(%s, %u) failed: %m",
+				my_ip == NULL ? "" : net_ip2addr(my_ip), *port);
+		}
+	} else {
+		/* get the actual port we started listen */
+		len = SIZEOF_SOCKADDR(so);
+		ret = getsockname(fd, &so.sa, &len);
+		if (ret >= 0) {
+			*port = sin_get_port(&so);
+
+			/* start listening */
+			if (listen(fd, backlog) >= 0)
+				return fd;
+
+			if (errno != EADDRINUSE)
+				i_error("listen() failed: %m");
+		}
+	}
+
+        /* error */
+	i_close_fd(&fd);
+	return -1;
+}
+
+int net_listen_unix(const char *path, int backlog)
+{
+	union {
+		struct sockaddr sa;
+		struct sockaddr_un un;
+	} sa;
+	int fd;
+
+	i_zero(&sa);
+	sa.un.sun_family = AF_UNIX;
+	if (i_strocpy(sa.un.sun_path, path, sizeof(sa.un.sun_path)) < 0) {
+		/* too long path */
+#ifdef ENAMETOOLONG
+		errno = ENAMETOOLONG;
+#else
+		errno = EOVERFLOW;
+#endif
+		return -1;
+	}
+
+	/* create the socket */
+	fd = socket(PF_UNIX, SOCK_STREAM, 0);
+	if (fd == -1) {
+		i_error("socket() failed: %m");
+		return -1;
+	}
+
+#ifdef NEEDS_LOCAL_CREDS
+	{
+		int on = 1;
+		if (setsockopt(fd, 0, LOCAL_CREDS, &on, sizeof on)) {
+			i_error("setsockopt(LOCAL_CREDS) failed: %m");
+			return -1;
+		}
+	}
+#endif
+
+	/* bind */
+	if (bind(fd, &sa.sa, sizeof(sa)) < 0) {
+		if (errno != EADDRINUSE)
+			i_error("bind(%s) failed: %m", path);
+	} else {
+		/* start listening */
+		if (listen(fd, backlog) == 0)
+			return fd;
+
+		if (errno != EADDRINUSE)
+			i_error("listen() failed: %m");
+	}
+
+	i_close_fd(&fd);
+	return -1;
+}
+
+int net_listen_unix_unlink_stale(const char *path, int backlog)
+{
+	unsigned int i = 0;
+	int fd;
+
+	while ((fd = net_listen_unix(path, backlog)) == -1) {
+		if (errno != EADDRINUSE || ++i == 2)
+			return -1;
+
+		/* see if it really exists */
+		fd = net_connect_unix(path);
+		if (fd != -1 || errno != ECONNREFUSED) {
+			i_close_fd(&fd);
+			errno = EADDRINUSE;
+			return -1;
+		}
+
+		/* delete and try again */
+		if (i_unlink_if_exists(path) < 0) {
+			errno = EADDRINUSE;
+			return -1;
+		}
+	}
+	return fd;
+}
+
+int net_accept(int fd, struct ip_addr *addr_r, in_port_t *port_r)
+{
+	union sockaddr_union so;
+	int ret;
+	socklen_t addrlen;
+
+	i_assert(fd >= 0);
+
+	i_zero(&so);
+	addrlen = sizeof(so);
+	ret = accept(fd, &so.sa, &addrlen);
+
+	if (ret < 0) {
+		if (errno == EAGAIN || errno == ECONNABORTED)
+			return -1;
+		else
+			return -2;
+	}
+	if (so.sin.sin_family == AF_UNIX) {
+		if (addr_r != NULL)
+			i_zero(addr_r);
+		if (port_r != NULL) *port_r = 0;
+	} else {
+		if (addr_r != NULL) sin_get_ip(&so, addr_r);
+		if (port_r != NULL) *port_r = sin_get_port(&so);
+	}
+	return ret;
+}
+
+ssize_t net_receive(int fd, void *buf, size_t len)
+{
+	ssize_t ret;
+
+	i_assert(fd >= 0);
+	i_assert(len <= SSIZE_T_MAX);
+
+	ret = read(fd, buf, len);
+	if (ret == 0) {
+		/* disconnected */
+		errno = 0;
+		return -2;
+	}
+
+	if (unlikely(ret < 0)) {
+		if (errno == EINTR || errno == EAGAIN)
+			return 0;
+
+		if (errno == ECONNRESET || errno == ETIMEDOUT) {
+                        /* treat as disconnection */
+			return -2;
+		}
+	}
+
+	return ret;
+}
+
+int net_gethostbyname(const char *addr, struct ip_addr **ips,
+		      unsigned int *ips_count)
+{
+	/* @UNSAFE */
+	union sockaddr_union *so;
+	struct addrinfo hints, *ai, *origai;
+	struct ip_addr ip;
+	int host_error;
+        int count;
+
+	*ips = NULL;
+        *ips_count = 0;
+
+	/* support [ipv6] style addresses here so they work globally */
+	if (addr[0] == '[' && net_addr2ip(addr, &ip) == 0) {
+		*ips_count = 1;
+		*ips = t_new(struct ip_addr, 1);
+		**ips = ip;
+		return 0;
+	}
+
+	i_zero(&hints);
+	hints.ai_socktype = SOCK_STREAM;
+
+	/* save error to host_error for later use */
+	host_error = getaddrinfo(addr, NULL, &hints, &ai);
+	if (host_error != 0)
+		return host_error;
+
+        /* get number of IPs */
+        origai = ai;
+	for (count = 0; ai != NULL; ai = ai->ai_next)
+                count++;
+
+        *ips_count = count;
+        *ips = t_new(struct ip_addr, count);
+
+        count = 0;
+	for (ai = origai; ai != NULL; ai = ai->ai_next, count++) {
+		so = (union sockaddr_union *) ai->ai_addr;
+
+		sin_get_ip(so, &(*ips)[count]);
+	}
+	freeaddrinfo(origai);
+
+	return 0;
+}
+
+int net_gethostbyaddr(const struct ip_addr *ip, const char **name_r)
+{
+	union sockaddr_union so;
+	socklen_t addrlen = sizeof(so);
+	char hbuf[NI_MAXHOST];
+	int ret;
+
+	i_zero(&so);
+	sin_set_ip(&so, ip);
+	ret = getnameinfo(&so.sa, addrlen, hbuf, sizeof(hbuf), NULL, 0,
+			  NI_NAMEREQD);
+	if (ret != 0)
+		return ret;
+
+	*name_r = t_strdup(hbuf);
+	return 0;
+}
+
+int net_getsockname(int fd, struct ip_addr *addr, in_port_t *port)
+{
+	union sockaddr_union so;
+	socklen_t addrlen;
+
+	i_assert(fd >= 0);
+
+	i_zero(&so);
+	addrlen = sizeof(so);
+	if (getsockname(fd, &so.sa, &addrlen) == -1)
+		return -1;
+	if (so.sin.sin_family == AF_UNIX) {
+		if (addr != NULL)
+			i_zero(addr);
+		if (port != NULL) *port = 0;
+	} else {
+		if (addr != NULL) sin_get_ip(&so, addr);
+		if (port != NULL) *port = sin_get_port(&so);
+	}
+	return 0;
+}
+
+int net_getpeername(int fd, struct ip_addr *addr, in_port_t *port)
+{
+	union sockaddr_union so;
+	socklen_t addrlen;
+
+	i_assert(fd >= 0);
+
+	i_zero(&so);
+	addrlen = sizeof(so);
+	if (getpeername(fd, &so.sa, &addrlen) == -1)
+		return -1;
+	if (so.sin.sin_family == AF_UNIX) {
+		if (addr != NULL)
+			i_zero(addr);
+		if (port != NULL) *port = 0;
+	} else {
+		if (addr != NULL) sin_get_ip(&so, addr);
+		if (port != NULL) *port = sin_get_port(&so);
+	}
+	return 0;
+}
+
+int net_getunixname(int fd, const char **name_r)
+{
+	union sockaddr_union_unix so;
+	socklen_t addrlen = sizeof(so);
+
+	i_zero(&so);
+	if (getsockname(fd, &so.sa, &addrlen) < 0)
+		return -1;
+	if (so.un.sun_family != AF_UNIX) {
+		errno = ENOTSOCK;
+		return -1;
+	}
+	*name_r = t_strdup(so.un.sun_path);
+	return 0;
+}
+
+int net_getunixcred(int fd, struct net_unix_cred *cred_r)
+{
+#if defined(SO_PEERCRED)
+# if defined(HAVE_STRUCT_SOCKPEERCRED)
+	/* OpenBSD (may also provide getpeereid, but we also want pid) */
+	struct sockpeercred ucred;
+# else
+	/* Linux */
+	struct ucred ucred;
+# endif
+	socklen_t len = sizeof(ucred);
+
+	if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &ucred, &len) < 0) {
+		i_error("getsockopt(SO_PEERCRED) failed: %m");
+		return -1;
+	}
+	cred_r->uid = ucred.uid;
+	cred_r->gid = ucred.gid;
+	cred_r->pid = ucred.pid;
+	return 0;
+#elif defined(LOCAL_PEEREID)
+	/* NetBSD (may also provide getpeereid, but we also want pid) */
+	struct unpcbid ucred;
+	socklen_t len = sizeof(ucred);
+
+	if (getsockopt(fd, 0, LOCAL_PEEREID, &ucred, &len) < 0) {
+		i_error("getsockopt(LOCAL_PEEREID) failed: %m");
+		return -1;
+	}
+	
+	cred_r->uid = ucred.unp_euid;
+	cred_r->gid = ucred.unp_egid;
+	cred_r->pid = ucred.unp_pid;
+	return 0;
+#elif defined(HAVE_GETPEEREID)
+	/* OSX 10.4+, FreeBSD 4.6+, OpenBSD 3.0+, NetBSD 5.0+ */
+	if (getpeereid(fd, &cred_r->uid, &cred_r->gid) < 0) {
+		i_error("getpeereid() failed: %m");
+		return -1;
+	}
+	cred_r->pid = (pid_t)-1;
+	return 0;
+#elif defined(LOCAL_PEERCRED)
+	/* Older FreeBSD */
+	struct xucred ucred;
+	socklen_t len = sizeof(ucred);
+
+	if (getsockopt(fd, 0, LOCAL_PEERCRED, &ucred, &len) < 0) {
+		i_error("getsockopt(LOCAL_PEERCRED) failed: %m");
+		return -1;
+	}
+
+	if (ucred.cr_version != XUCRED_VERSION) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	cred_r->uid = ucred.cr_uid;
+	cred_r->gid = ucred.cr_gid;
+	cred_r->pid = (pid_t)-1;
+	return 0;
+#elif defined(HAVE_GETPEERUCRED)
+	/* Solaris */
+	ucred_t *ucred = NULL;
+
+	if (getpeerucred(fd, &ucred) < 0) {
+		i_error("getpeerucred() failed: %m");
+		return -1;
+	}
+	cred_r->uid = ucred_geteuid(ucred);
+	cred_r->gid = ucred_getrgid(ucred);
+	cred_r->pid = ucred_getpid(ucred);
+	ucred_free(ucred);
+
+	if (cred_r->uid == (uid_t)-1 ||
+	    cred_r->gid == (gid_t)-1) {
+		errno = EINVAL;
+		return -1;
+	}
+	return 0;
+#elif defined(NEEDS_LOCAL_CREDS)
+	/* NetBSD < 5 */
+	int i, n, on;
+	struct iovec iov;
+	struct msghdr msg;
+	struct {
+		struct cmsghdr ch;
+		char buf[110];
+	} cdata;
+	struct sockcred *sc;
+
+	iov.iov_base = (char *)&on;
+	iov.iov_len = 1;
+
+	sc = (struct sockcred *)cdata.buf;
+	sc->sc_uid = sc->sc_euid = sc->sc_gid = sc->sc_egid = -1;
+	i_zero(&cdata.ch);
+
+	i_zero(&msg);
+
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = &cdata;
+	msg.msg_controllen = sizeof(cdata.ch) + sizeof(cdata.buf);
+
+	for (i = 0; i < 10; i++) {
+		n = recvmsg(fd, &msg, MSG_WAITALL | MSG_PEEK);
+		if (n >= 0 || errno != EAGAIN)
+			break;
+		usleep(100);
+	}
+	if (n < 0) {
+		i_error("recvmsg() failed: %m");
+		return -1;
+	}
+	cred_r->uid = sc->sc_euid;
+	cred_r->gid = sc->sc_egid;
+	cred_r->pid = (pid_t)-1;
+	return 0;
+#else
+	errno = EINVAL;
+	return -1;
+#endif
+}
+
+const char *net_ip2addr(const struct ip_addr *ip)
+{
+	char *addr = t_malloc_no0(MAX_IP_LEN+1);
+
+	if (inet_ntop(ip->family, &ip->u.ip6, addr, MAX_IP_LEN) == NULL)
+		return "";
+
+	return addr;
+}
+
+static bool net_addr2ip_inet4_fast(const char *addr, struct ip_addr *ip)
+{
+	uint8_t *saddr = (void *)&ip->u.ip4.s_addr;
+	unsigned int i, num;
+
+	if (str_parse_uint(addr, &num, &addr) < 0)
+		return FALSE;
+	if (*addr == '\0' && num <= 0xffffffff) {
+		/* single-number IPv4 address */
+		ip->u.ip4.s_addr = htonl(num);
+		ip->family = AF_INET;
+		return TRUE;
+	}
+
+	/* try to parse as a.b.c.d */
+	i = 0;
+	for (;;) {
+		if (num >= 256)
+			return FALSE;
+		saddr[i] = num;
+		if (i == 3)
+			break;
+		i++;
+		if (*addr != '.')
+			return FALSE;
+		addr++;
+		if (str_parse_uint(addr, &num, &addr) < 0)
+			return FALSE;
+	}
+	if (*addr != '\0')
+		return FALSE;
+	ip->family = AF_INET;
+	return TRUE;
+}
+
+int net_addr2ip(const char *addr, struct ip_addr *ip)
+{
+	int ret;
+
+	if (net_addr2ip_inet4_fast(addr, ip))
+		return 0;
+
+	if (strchr(addr, ':') != NULL) {
+		/* IPv6 */
+		T_BEGIN {
+			if (addr[0] == '[') {
+				/* allow [ipv6 addr] */
+				size_t len = strlen(addr);
+				if (addr[len-1] == ']')
+					addr = t_strndup(addr+1, len-2);
+			}
+			ret = inet_pton(AF_INET6, addr, &ip->u.ip6);
+		} T_END;
+		if (ret == 0)
+			return -1;
+		ip->family = AF_INET6;
+ 	} else {
+		/* IPv4 */
+		if (inet_aton(addr, &ip->u.ip4) == 0)
+			return -1;
+		ip->family = AF_INET;
+	}
+	return 0;
+}
+
+int net_str2port(const char *str, in_port_t *port_r)
+{
+	uintmax_t l;
+
+	if (str_to_uintmax(str, &l) < 0)
+		return -1;
+
+	if (l == 0 || l > (in_port_t)-1)
+		return -1;
+	*port_r = (in_port_t)l;
+	return 0;
+}
+
+int net_str2port_zero(const char *str, in_port_t *port_r)
+{
+	uintmax_t l;
+
+	if (str_to_uintmax(str, &l) < 0)
+		return -1;
+
+	if (l > (in_port_t)-1)
+		return -1;
+	*port_r = (in_port_t)l;
+	return 0;
+}
+
+int net_str2hostport(const char *str, in_port_t default_port,
+		     const char **host_r, in_port_t *port_r)
+{
+	const char *p, *host;
+	in_port_t port;
+
+	if (str[0] == '[') {
+		/* [IPv6] address, possibly followed by :port */
+		p = strchr(str, ']');
+		if (p == NULL)
+			return -1;
+		host = t_strdup_until(str+1, p++);
+	} else {
+		p = strchr(str, ':');
+		if (p == NULL || strchr(p+1, ':') != NULL) {
+			/* host or IPv6 address */
+			*host_r = str;
+			*port_r = default_port;
+			return 0;
+		}
+		host = t_strdup_until(str, p);
+	}
+	if (p[0] == '\0') {
+		*host_r = host;
+		*port_r = default_port;
+		return 0;
+	}
+	if (p[0] != ':')
+		return -1;
+	if (net_str2port(p+1, &port) < 0)
+		return -1;
+	*host_r = host;
+	*port_r = port;
+	return 0;
+}
+
+int net_ipport2str(const struct ip_addr *ip, in_port_t port, const char **str_r)
+{
+	if (!IPADDR_IS_V4(ip) && !IPADDR_IS_V6(ip)) return -1;
+
+	*str_r = t_strdup_printf("%s%s%s:%u",
+				 IPADDR_IS_V6(ip) ? "[" : "",
+				 net_ip2addr(ip),
+				 IPADDR_IS_V6(ip) ? "]" : "",
+				 port);
+	return 0;
+}
+
+int net_ipv6_mapped_ipv4_convert(const struct ip_addr *src,
+				 struct ip_addr *dest)
+{
+	static uint8_t v4_prefix[] =
+		{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff };
+
+	if (!IPADDR_IS_V6(src))
+		return -1;
+	if (memcmp(src->u.ip6.s6_addr, v4_prefix, sizeof(v4_prefix)) != 0)
+		return -1;
+
+	i_zero(dest);
+	dest->family = AF_INET;
+	memcpy(&dest->u.ip6, &src->u.ip6.s6_addr[3*4], 4);
+	return 0;
+}
+
+int net_geterror(int fd)
+{
+	int data;
+	socklen_t len = sizeof(data);
+
+	if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &data, &len) == -1) {
+		/* we're now really returning the getsockopt()'s error code
+		   instead of the socket's, but normally we should never get
+		   here anyway. */
+		return errno;
+	}
+
+	return data;
+}
+
+const char *net_gethosterror(int error)
+{
+	i_assert(error != 0);
+
+	return gai_strerror(error);
+}
+
+enum net_hosterror_type net_get_hosterror_type(int error)
+{
+	const struct {
+		int error;
+		enum net_hosterror_type type;
+	} error_map[] = {
+#ifdef EAI_ADDRFAMILY /* Obsoleted by RFC 2553bis-02 */
+		{ EAI_ADDRFAMILY, NET_HOSTERROR_TYPE_NOT_FOUND },
+#endif
+		{ EAI_AGAIN, NET_HOSTERROR_TYPE_NAMESERVER },
+		{ EAI_BADFLAGS, NET_HOSTERROR_TYPE_INTERNAL_ERROR },
+		{ EAI_FAIL, NET_HOSTERROR_TYPE_NAMESERVER },
+		{ EAI_FAMILY, NET_HOSTERROR_TYPE_INTERNAL_ERROR },
+		{ EAI_MEMORY, NET_HOSTERROR_TYPE_INTERNAL_ERROR },
+#ifdef EAI_NODATA /* Obsoleted by RFC 2553bis-02 */
+		{ EAI_NODATA, NET_HOSTERROR_TYPE_NOT_FOUND },
+#endif
+		{ EAI_NONAME, NET_HOSTERROR_TYPE_NOT_FOUND },
+		{ EAI_SERVICE, NET_HOSTERROR_TYPE_INTERNAL_ERROR },
+		{ EAI_SOCKTYPE, NET_HOSTERROR_TYPE_INTERNAL_ERROR },
+		{ EAI_SYSTEM, NET_HOSTERROR_TYPE_INTERNAL_ERROR },
+	};
+	for (unsigned int i = 0; i < N_ELEMENTS(error_map); i++) {
+		if (error_map[i].error == error)
+			return error_map[i].type;
+	}
+
+	/* shouldn't happen? assume internal error */
+	return NET_HOSTERROR_TYPE_INTERNAL_ERROR;
+}
+
+int net_hosterror_notfound(int error)
+{
+#ifdef EAI_NODATA /* NODATA is depricated */
+	return (error != 1 && (error == EAI_NONAME || error == EAI_NODATA)) ? 1 : 0;
+#else
+	return (error != 1 && (error == EAI_NONAME)) ? 1 : 0;
+#endif
+}
+
+const char *net_getservbyport(in_port_t port)
+{
+	struct servent *entry;
+
+	entry = getservbyport(htons(port), "tcp");
+	return entry == NULL ? NULL : entry->s_name;
+}
+
+bool is_ipv4_address(const char *addr)
+{
+	while (*addr != '\0') {
+		if (*addr != '.' && !i_isdigit(*addr))
+			return FALSE;
+                addr++;
+	}
+
+	return TRUE;
+}
+
+bool is_ipv6_address(const char *addr)
+{
+	bool have_prefix = FALSE;
+
+	if (*addr == '[') {
+		have_prefix = TRUE;
+		addr++;
+	}
+	while (*addr != '\0') {
+		if (*addr != ':' && !i_isxdigit(*addr)) {
+			if (have_prefix && *addr == ']' && addr[1] == '\0')
+				break;
+			return FALSE;
+		}
+                addr++;
+	}
+
+	return TRUE;
+}
+
+int net_parse_range(const char *network, struct ip_addr *ip_r,
+		    unsigned int *bits_r)
+{
+	const char *p;
+	unsigned int bits, max_bits;
+
+	p = strchr(network, '/');
+	if (p != NULL)
+		network = t_strdup_until(network, p++);
+
+	if (net_addr2ip(network, ip_r) < 0)
+		return -1;
+
+	max_bits = IPADDR_BITS(ip_r);
+	if (p == NULL) {
+		/* full IP address must match */
+		bits = max_bits;
+	} else {
+		/* get the network mask */
+		if (str_to_uint(p, &bits) < 0 || bits > max_bits)
+			return -1;
+	}
+	*bits_r = bits;
+	return 0;
+}
+
+bool net_is_in_network(const struct ip_addr *ip,
+		       const struct ip_addr *net_ip, unsigned int bits)
+{
+	struct ip_addr tmp_ip;
+	const uint32_t *ip1, *ip2;
+	uint32_t mask, i1, i2;
+	unsigned int pos, i;
+
+	if (net_ipv6_mapped_ipv4_convert(ip, &tmp_ip) == 0) {
+		/* IPv4 address mapped disguised as IPv6 address */
+		ip = &tmp_ip;
+	}
+
+	if (ip->family == 0 || net_ip->family == 0) {
+		/* non-IPv4/IPv6 address (e.g. UNIX socket) never matches
+		   anything */
+		return FALSE;
+	}
+	if (IPADDR_IS_V4(ip) != IPADDR_IS_V4(net_ip)) {
+		/* one is IPv6 and one is IPv4 */
+		return FALSE;
+	}
+	i_assert(IPADDR_IS_V6(ip) == IPADDR_IS_V6(net_ip));
+
+	if (IPADDR_IS_V4(ip)) {
+		ip1 = &ip->u.ip4.s_addr;
+		ip2 = &net_ip->u.ip4.s_addr;
+	} else {
+		ip1 = (const void *)&ip->u.ip6;
+		ip2 = (const void *)&net_ip->u.ip6;
+	}
+
+	/* check first the full 32bit ints */
+	for (pos = 0, i = 0; pos + 32 <= bits; pos += 32, i++) {
+		if (ip1[i] != ip2[i])
+			return FALSE;
+	}
+	i1 = htonl(ip1[i]);
+	i2 = htonl(ip2[i]);
+
+	/* check the last full bytes */
+	for (mask = 0xff000000; pos + 8 <= bits; pos += 8, mask >>= 8) {
+		if ((i1 & mask) != (i2 & mask))
+			return FALSE;
+	}
+
+	/* check the last bits, they're reversed in bytes */
+	bits -= pos;
+	for (mask = 0x80000000 >> (pos % 32); bits > 0; bits--, mask >>= 1) {
+		if ((i1 & mask) != (i2 & mask))
+			return FALSE;
+	}
+	return TRUE;
+}