/*
- * Copyright (C) 2005-2007 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
/** \file net.c Networking-related helper functions. */
-#include <netdb.h> /* hostent */
+#include <netdb.h>
+
+/* At least NetBSD needs these. */
+#ifndef AI_V4MAPPED
+#define AI_V4MAPPED 0
+#endif
+#ifndef AI_ALL
+#define AI_ALL 0
+#endif
+#ifndef AI_ADDRCONFIG
+#define AI_ADDRCONFIG 0
+#endif
+
#include "para.h"
#include "error.h"
/**
- * Initialize a struct sockaddr_in.
+ * Determine the socket type for a given layer-4 protocol.
*
- * \param addr A pointer to the struct to be initialized.
- * \param port The port number to use.
- * \param he The address to use.
+ * \param l4type The symbolic name of the transport-layer protocol.
*
- * If \a he is null (server mode), \a addr->sin_addr is initialized with \p
- * INADDR_ANY. Otherwise, the address given by \a he is copied to addr.
+ * \sa ip(7), socket(2)
*/
-static void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he)
+static inline int sock_type(const unsigned l4type)
{
- /* host byte order */
- addr->sin_family = AF_INET;
- /* short, network byte order */
- addr->sin_port = htons(port);
- if (he)
- addr->sin_addr = *((struct in_addr *)he->h_addr);
- else
- addr->sin_addr.s_addr = INADDR_ANY;
- /* zero the rest of the struct */
- memset(&addr->sin_zero, '\0', 8);
+ switch (l4type) {
+ case IPPROTO_UDP: return SOCK_DGRAM;
+ case IPPROTO_TCP: return SOCK_STREAM;
+ case IPPROTO_DCCP: return SOCK_DCCP;
+ }
+ return -1; /* not supported here */
+}
+
+/**
+ * Pretty-print transport-layer name.
+ */
+static const char *layer4_name(const unsigned l4type)
+{
+ switch (l4type) {
+ case IPPROTO_UDP: return "UDP";
+ case IPPROTO_TCP: return "TCP";
+ case IPPROTO_DCCP: return "DCCP";
+ }
+ return "UNKNOWN PROTOCOL";
+}
+
+/**
+ * Resolve IPv4/IPv6 address and create a ready-to-use active or passive socket.
+ *
+ * \param l3type The layer-3 type (\p AF_INET, \p AF_INET6, \p AF_UNSPEC).
+ * \param l4type The layer-4 type (\p IPPROTO_xxx).
+ * \param passive Whether this is a passive (1) or active (0) socket.
+ * \param host Remote or local hostname or IPv/6 address string.
+ * \param port_number Decimal port number.
+ *
+ * This creates a ready-made IPv4/v6 socket structure after looking up the
+ * necessary parameters. The interpretation of \a host depends on the value of
+ * \a passive:
+ * - on a passive socket host is interpreted as an interface IPv4/6 address
+ * (can be left NULL);
+ * - on an active socket, \a host is the peer DNS name or IPv4/6 address
+ * to connect to;
+ * - \a port_number is in either case the numeric port number (not service
+ * string).
+ *
+ * Furthermore, bind(2) is called on passive sockets, and connect(2) on active
+ * sockets. The algorithm tries all possible address combinations until it
+ * succeeds.
+ *
+ * \return This function returns 1 on success and \a -E_ADDRESS_LOOKUP when no
+ * matching connection could be set up (with details in the error log).
+ *
+ * \sa ipv6(7), getaddrinfo(3), bind(2), connect(2).
+ */
+int makesock(unsigned l3type, unsigned l4type, int passive,
+ const char *host, unsigned short port_number)
+{
+ struct addrinfo *local = NULL, *src,
+ *remote = NULL, *dst, hints;
+ int rc, on = 1, sockfd = -1,
+ socktype = sock_type(l4type);
+ char port[6]; /* port number has at most 5 digits */
+
+ sprintf(port, "%u", port_number);
+ /* Set up address hint structure */
+ memset(&hints, 0, sizeof(hints));
+ hints.ai_family = l3type;
+ /* getaddrinfo does not really work well with SOCK_DCCP */
+ if (socktype == SOCK_DGRAM || socktype == SOCK_STREAM)
+ hints.ai_socktype = socktype;
+
+ /* only use addresses available on the host */
+ hints.ai_flags = AI_ADDRCONFIG;
+ if (l3type == AF_INET6)
+ /* use v4-mapped-v6 if no v6 addresses found */
+ hints.ai_flags |= AI_V4MAPPED | AI_ALL;
+
+ if (passive && host == NULL)
+ hints.ai_flags |= AI_PASSIVE;
+
+ /* Obtain local/remote address information */
+ if ((rc = getaddrinfo(host, port, &hints, passive ? &local : &remote))) {
+ PARA_ERROR_LOG("can not resolve %s address %s#%s: %s.\n",
+ layer4_name(l4type),
+ host? host : (passive? "[loopback]" : "[localhost]"),
+ port, gai_strerror(rc));
+ return -E_ADDRESS_LOOKUP;
+ }
+
+ /* Iterate over all src/dst combination, exhausting dst first */
+ for (src = local, dst = remote; src != NULL || dst != NULL; /* no op */ ) {
+ if (src && dst && src->ai_family == AF_INET
+ && dst->ai_family == AF_INET6)
+ goto get_next_dst; /* v4 -> v6 is not possible */
+
+ sockfd = socket(src ? src->ai_family : dst->ai_family,
+ socktype, l4type);
+ if (sockfd < 0)
+ goto get_next_dst;
+
+ /*
+ * Set those options that need to be set before establishing
+ * the connection. Reuse the address on passive (listening)
+ * sockets to avoid failure on restart.
+ */
+ if (passive && setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
+ &on, sizeof(on)) == -1) {
+ PARA_ERROR_LOG("can not set SO_REUSEADDR: %s\n",
+ strerror(errno));
+ return -ERRNO_TO_PARA_ERROR(errno);
+ }
+
+ if (src) {
+ if (bind(sockfd, src->ai_addr, src->ai_addrlen) < 0) {
+ close(sockfd);
+ goto get_next_src;
+ }
+ if (!dst) /* bind-only completed successfully */
+ break;
+ }
+
+ if (dst && connect(sockfd, dst->ai_addr, dst->ai_addrlen) == 0)
+ break; /* connection completed successfully */
+ close(sockfd);
+get_next_dst:
+ if (dst && (dst = dst->ai_next))
+ continue;
+get_next_src:
+ if (src && (src = src->ai_next)) /* restart inner loop */
+ dst = remote;
+ }
+ if (local)
+ freeaddrinfo(local);
+ if (remote)
+ freeaddrinfo(remote);
+
+ if (src == NULL && dst == NULL) {
+ PARA_ERROR_LOG("can not create %s socket %s#%s.\n",
+ layer4_name(l4type), host? host : (passive?
+ "[loopback]" : "[localhost]"), port);
+ return -ERRNO_TO_PARA_ERROR(errno);
+ }
+ return sockfd;
+}
+
+/**
+ * Create a passive / listening socket.
+ *
+ * \param l3type The network-layer type (\p AF_xxx).
+ * \param l4type The transport-layer type (\p IPPROTO_xxx).
+ * \param port The decimal port number to listen on.
+ *
+ * \return Positive integer (socket descriptor) on success, negative value
+ * otherwise.
+ *
+ * \sa makesock(), ip(7), ipv6(7), bind(2), listen(2).
+ */
+int para_listen(unsigned l3type, unsigned l4type, unsigned short port)
+{
+ int ret, fd = makesock(l3type, l4type, 1, NULL, port);
+
+ if (fd > 0) {
+ ret = listen(fd, BACKLOG);
+ if (ret < 0) {
+ close(fd);
+ return -ERRNO_TO_PARA_ERROR(errno);
+ }
+ PARA_INFO_LOG("listening on %s port %u, fd %d\n",
+ layer4_name(l4type), port, fd);
+ }
+ return fd;
+}
+
+/**
+ * Print numeric host and port number (beware - uses static char).
+ *
+ * \param sa The IPv4/IPv6 socket address to use.
+ * \param len The length of \p sa.
+ *
+ * \sa getnameinfo(3).
+ */
+static char *host_and_port(struct sockaddr *sa, socklen_t len)
+{
+ static char output[NI_MAXHOST + NI_MAXSERV + 2];
+ char hbuf[NI_MAXHOST], sbuf[NI_MAXSERV];
+ int ret;
+
+ ret = getnameinfo(sa, len, hbuf, sizeof(hbuf), sbuf, sizeof(sbuf),
+ NI_NUMERICHOST | NI_NUMERICSERV);
+ if (ret) {
+ PARA_WARNING_LOG("hostname lookup error (%s).\n",
+ gai_strerror(ret));
+ sprintf(output, "(unknown)");
+ } else
+ sprintf(output, "%s#%s", hbuf, sbuf);
+ return output;
+}
+
+/**
+ * Look up the local or remote side of a connected socket structure.
+ *
+ * \param fd The socket descriptor of the connected socket.
+ * \param getname Either \p getsockname() for local, or \p getpeername() for
+ * remote side.
+ *
+ * \return A static character string identifying hostname and port of the
+ * chosen side.
+ *
+ * \sa getsockname(2), getpeername(2).
+ */
+static char *__get_sock_name(int fd, int (*getname)(int, struct sockaddr*,
+ socklen_t *))
+{
+ struct sockaddr_storage ss;
+ socklen_t sslen = sizeof(ss);
+
+ if (getname(fd, (struct sockaddr *)&ss, &sslen) < 0) {
+ static char *dont_know = "(don't know)";
+ PARA_ERROR_LOG("can not determine address from fd %d: %s\n",
+ fd, strerror(errno));
+ return dont_know;
+ }
+ return host_and_port((struct sockaddr *)&ss, sslen);
+}
+
+char *local_name(int sockfd)
+{
+ return __get_sock_name(sockfd, getsockname);
+}
+
+char *remote_name(int sockfd)
+{
+ return __get_sock_name(sockfd, getpeername);
+}
+
+/**
+ * Extract IPv4 or IPv6-mapped-IPv4 address from sockaddr_storage.
+ * \param ss Container of IPv4/6 address
+ * \return Extracted IPv4 address (different from 0) or 0 if unsuccessful.
+ *
+ * \sa RFC 3493
+ */
+struct in_addr extract_v4_addr(const struct sockaddr_storage *ss)
+{
+ struct in_addr ia = {.s_addr = 0};
+
+ if (ss->ss_family == AF_INET)
+ ia.s_addr = ((struct sockaddr_in *)ss)->sin_addr.s_addr;
+ if (ss->ss_family == AF_INET6) {
+ const struct in6_addr v6_addr = ((struct sockaddr_in6 *)ss)->sin6_addr;
+
+ if (IN6_IS_ADDR_V4MAPPED(&v6_addr))
+ memcpy(&ia.s_addr, &(v6_addr.s6_addr[12]), 4);
+ }
+ return ia;
}
/*
assert(total);
*len = 0;
while (*len < total) {
- int ret = send(fd, buf + *len, total - *len, 0);
+ int ret = write(fd, buf + *len, total - *len);
if (ret == -1)
return -ERRNO_TO_PARA_ERROR(errno);
*len += ret;
return n;
}
-/**
- * Establish a tcp connection.
- *
- * \param host Hostname or IPv4 address.
- * \param port The tcp port.
- *
- * \return Negative on errors, a valid file descriptor on success.
- */
-int tcp_connect(char *host, int port)
-{
- struct sockaddr_in addr;
- struct hostent *he;
- int ret, fd;
-
- PARA_INFO_LOG("getting host info of %s\n", host);
- /* FIXME: gethostbyname() is obsolete */
- he = gethostbyname(host);
- if (!he)
- return -ERRNO_TO_PARA_ERROR(h_errno);
- init_sockaddr(&addr, port, he);
- ret = get_stream_socket(AF_INET);
- if (ret < 0)
- return ret;
- fd = ret;
- ret = PARA_CONNECT(fd, &addr);
- if (ret >= 0)
- return fd;
- close(fd);
- return ret;
-}
-
-/**
- * A wrapper around socket(2).
- *
- * \param domain The communication domain that selects the protocol family.
- *
- * Create an IPv4 socket for sequenced, reliable, two-way, connection-based
- * byte streams.
- *
- * \return The socket fd on success, negative on errors.
- *
- * \sa socket(2).
- */
-int get_stream_socket(int domain)
-{
- int fd = socket(domain, SOCK_STREAM, 0);
-
- if (fd < 0)
- return -ERRNO_TO_PARA_ERROR(errno);
- return fd;
-}
-
/**
* Wrapper around the accept system call.
*
}
/**
- * prepare a structure for \p AF_UNIX socket addresses
+ * Prepare a structure for \p AF_UNIX socket addresses.
*
- * \param u pointer to the struct to be prepared
- * \param name the socket pathname
+ * \param u Pointer to the struct to be prepared.
+ * \param name The socket pathname.
*
* This just copies \a name to the sun_path component of \a u.
*
* \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer
* than \p UNIX_PATH_MAX.
*/
-int init_unix_addr(struct sockaddr_un *u, const char *name)
+static int init_unix_addr(struct sockaddr_un *u, const char *name)
{
if (strlen(name) >= UNIX_PATH_MAX)
return -E_NAME_TOO_LONG;
* \param unix_addr Pointer to the \p AF_UNIX socket structure.
* \param mode The desired mode of the socket.
*
- * This functions creates a local socket for sequenced, reliable,
+ * This function creates a local socket for sequenced, reliable,
* two-way, connection-based byte streams.
*
* \return The file descriptor, on success, negative on errors.
return ret;
}
+/**
+ * Prepare, create, and connect to a Unix domain socket for local communication.
+ *
+ * \param name The socket pathname.
+ *
+ * This function creates a local socket for sequenced, reliable, two-way,
+ * connection-based byte streams.
+ *
+ * \return The file descriptor, on success, negative on errors.
+ *
+ * \sa create_local_socket(), unix(7), connect(2).
+ */
+int create_remote_socket(const char *name)
+{
+ struct sockaddr_un unix_addr;
+ int fd, ret;
+
+ ret = init_unix_addr(&unix_addr, name);
+ if (ret < 0)
+ return ret;
+ fd = socket(PF_UNIX, SOCK_STREAM, 0);
+ if (fd < 0)
+ return -ERRNO_TO_PARA_ERROR(errno);
+ if (connect(fd, (struct sockaddr *)&unix_addr, sizeof(unix_addr)) == -1) {
+ ret = -ERRNO_TO_PARA_ERROR(errno);
+ goto err;
+ }
+ return fd;
+err:
+ close(fd);
+ return ret;
+}
+
#ifndef HAVE_UCRED
ssize_t send_cred_buffer(int sock, char *buf)
{
}
#else /* HAVE_UCRED */
/**
- * send NULL terminated buffer and Unix credentials of the current process
+ * Send \p NULL-terminated buffer and Unix credentials of the current process.
*
- * \param sock the socket file descriptor
- * \param buf the buffer to be sent
+ * \param sock The socket file descriptor.
+ * \param buf The buffer to be sent.
*
* \return On success, this call returns the number of characters sent. On
* error, \p -E_SENDMSG is returned.
*
- * \sa okir's Black Hats Manual
- * \sa sendmsg(2)
+ * \sa sendmsg(2), okir's Black Hats Manual.
*/
ssize_t send_cred_buffer(int sock, char *buf)
{
}
/**
- * receive a buffer and the Unix credentials of the sending process
+ * Receive a buffer and the Unix credentials of the sending process.
*
- * \param fd the socket file descriptor
- * \param buf the buffer to store the message
- * \param size the size of \a buffer
+ * \param fd the socket file descriptor.
+ * \param buf the buffer to store the message.
+ * \param size the size of \a buffer.
*
* \return negative on errors, the user id on success.
*
- * \sa okir's Black Hats Manual
- * \sa recvmsg(2)
+ * \sa recvmsg(2), okir's Black Hats Manual.
*/
int recv_cred_buffer(int fd, char *buf, size_t size)
{
}
#endif /* HAVE_UCRED */
-/** how many pending connections queue will hold */
-#define BACKLOG 10
-
-/**
- * Create a tcp socket, bind it and listen on the given port.
- *
- * \param Port the tcp port to listen on.
- *
- * \return The file descriptor of the created socket, negative on errors.
- *
- * \sa get_stream_socket()
- * \sa setsockopt(2)
- * \sa bind(2)
- * \sa listen(2)
- */
-int tcp_listen(int port)
-{
- struct sockaddr_in my_addr;
- int fd, ret = get_stream_socket(AF_INET);
-
- if (ret < 0)
- return ret;
- fd = ret;
- ret = 1;
- ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &ret, sizeof(int));
- if (ret < 0) {
- ret = -ERRNO_TO_PARA_ERROR(errno);
- goto err;
- }
- init_sockaddr(&my_addr, port, NULL);
- ret = bind(fd, (struct sockaddr *)&my_addr, sizeof(struct sockaddr));
- if (ret < 0) {
- ret = -ERRNO_TO_PARA_ERROR(errno);
- goto err;
- }
- ret = listen(fd, BACKLOG);
- if (ret < 0) {
- ret = -ERRNO_TO_PARA_ERROR(errno);
- goto err;
- }
- PARA_INFO_LOG("listening on port %d, fd %d\n", port, fd);
- return fd;
-err:
- close(fd);
- return ret;
-}
-
/**
- * receive a buffer and check for a pattern
+ * Receive a buffer and check for a pattern.
*
- * \param fd the file descriptor to receive from
- * \param pattern the expected pattern
- * \param bufsize the size of the internal buffer
+ * \param fd The file descriptor to receive from.
+ * \param pattern The expected pattern.
+ * \param bufsize The size of the internal buffer.
*
* \return Positive if \a pattern was received, negative otherwise.
*
* If at least \p strlen(\a pattern) bytes were received, the beginning of
* the received buffer is compared with \a pattern, ignoring case.
*
- * \sa recv_buffer()
- * \sa strncasecmp(3)
+ * \sa recv_buffer(), \sa strncasecmp(3).
*/
int recv_pattern(int fd, const char *pattern, size_t bufsize)
{
ret = 1;
out:
if (ret < 0) {
- PARA_NOTICE_LOG("n = %d, did not receive pattern '%s'\n", n, pattern);
+ PARA_NOTICE_LOG("n = %d, did not receive pattern '%s'\n", n,
+ pattern);
if (n > 0)
PARA_NOTICE_LOG("recvd: %s\n", buf);
}
projects / paraslash.git / blobdiff