/*
- * Copyright (C) 2005-2007 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
*
* Licensed under the GPL v2. For licencing details see COPYING.
*/
/** \file net.c Networking-related helper functions. */
+/*
+ * Since glibc 2.8, the _GNU_SOURCE feature test macro must be defined in order
+ * to obtain the definition of the ucred structure.
+ */
+#define _GNU_SOURCE
+
#include <netdb.h>
/* At least NetBSD needs these. */
#define AI_ADDRCONFIG 0
#endif
+#include <dirent.h>
+#include <regex.h>
#include "para.h"
#include "error.h"
#include "net.h"
#include "string.h"
+#include "fd.h"
/** Information about one encrypted connection. */
crypt_data_array[fd].private_data = NULL;
}
+/**
+ * Match string as a candidate IPv4 address.
+ *
+ * \param address The string to match.
+ * \return True if \a address has "dot-quad" format.
+ */
+static bool is_v4_dot_quad(const char *address)
+{
+ bool result;
+ regex_t r;
+
+ assert(!regcomp(&r, "^([0-9]+\\.){3}[0-9]+$", REG_EXTENDED|REG_NOSUB));
+ result = regexec(&r, address, 0, NULL, 0) == 0;
+ regfree(&r);
+ return result;
+}
+
+/**
+ * Perform basic syntax checking on the host-part of an URL:
+ *
+ * - Since ':' is invalid in IPv4 addresses and DNS names, the
+ * presence of ':' causes interpretation as IPv6 address;
+ * - next the first-match-wins algorithm from RFC 3986 is applied;
+ * - else the string is considered as DNS name, to be resolved later.
+ *
+ * \param host The host string to check.
+ * \return True if \a host passes the syntax checks.
+ *
+ * \sa RFC 3986, 3.2.2; RFC 1123, 2.1; RFC 1034, 3.5
+ */
+static bool host_string_ok(const char *host)
+{
+ if (host == NULL || *host == '\0')
+ return false;
+ if (strchr(host, ':') != NULL)
+ return is_valid_ipv6_address(host);
+ if (is_v4_dot_quad(host))
+ return is_valid_ipv4_address(host);
+ return true;
+}
+
+/**
+ * Parse and validate URL string.
+ *
+ * The URL syntax is loosely based on RFC 3986, supporting one of
+ * - "["host"]"[:port] for native IPv6 addresses and
+ * - host[:port] for IPv4 hostnames and DNS names.
+ *
+ * Native IPv6 addresses must be enclosed in square brackets, since
+ * otherwise there is an ambiguity with the port separator `:'.
+ * The 'port' part is always considered to be a number; if absent,
+ * it is set to -1, to indicate that a default port is to be used.
+ *
+ * The following are valid examples:
+ * - 10.10.1.1
+ * - 10.10.1.2:8000
+ * - localhost
+ * - localhost:8001
+ * - [::1]:8000
+ * - [badc0de::1]
+ *
+ * \param url The URL string to take apart.
+ * \param host To return the copied host part of \a url.
+ * \param hostlen The maximum length of \a host.
+ * \param port To return the port number (if any) of \a url.
+ *
+ * \return Pointer to \a host, or NULL if failed.
+ * If NULL is returned, \a host and \a portnum are undefined. If no
+ * port number was present in \a url, \a portnum is set to -1.
+ *
+ * \sa RFC 3986, 3.2.2/3.2.3
+ */
+char *parse_url(const char *url,
+ char *host, ssize_t hostlen,
+ int32_t *port)
+{
+ const char *o = url;
+ char *c = host, *end = c + (hostlen - 1);
+
+ *port = -1;
+
+ if (o == NULL || hostlen < 1)
+ goto failed;
+
+ if (*o == '[') {
+ for (++o; (*c = *o == ']' ? '\0' : *o); c++, o++)
+ if (c == end)
+ goto failed;
+
+ if (*o++ != ']' || (*o != '\0' && *o != ':'))
+ goto failed;
+ } else {
+ for (; (*c = *o == ':'? '\0' : *o); c++, o++)
+ if (c == end)
+ goto failed;
+ }
+
+ if (*o == ':')
+ if (para_atoi32(++o, port) < 0 ||
+ *port < 0 || *port > 0xffff)
+ goto failed;
+
+ if (host_string_ok(host))
+ return host;
+failed:
+ *host = '\0';
+ return NULL;
+}
/**
* Determine the socket type for a given layer-4 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)
+ * \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)
+ const char *host, unsigned short port_number)
{
struct addrinfo *local = NULL, *src,
*remote = NULL, *dst, hints;
- char *port = make_message("%u", port_number);
int rc, on = 1, sockfd = -1,
socktype = sock_type(l4type);
+ char port[6]; /* port number has at most 5 digits */
- /*
- * Set up address hint structure
- */
+ 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;
+ hints.ai_socktype = socktype;
+ /*
+ * getaddrinfo does not support SOCK_DCCP, so for the sake of lookup
+ * (and only then) pretend to be UDP.
+ */
+ if (l4type == IPPROTO_DCCP)
+ hints.ai_socktype = SOCK_DGRAM;
/* only use addresses available on the host */
hints.ai_flags = AI_ADDRCONFIG;
if (passive && host == NULL)
hints.ai_flags |= AI_PASSIVE;
- /*
- * Obtain local/remote address information
- */
+ /* 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? : (passive? "[loopback]" : "[localhost]"),
+ host? host : (passive? "[loopback]" : "[localhost]"),
port, gai_strerror(rc));
return -E_ADDRESS_LOOKUP;
}
- /*
- * Iterate over all src/dst combination, exhausting dst first
- */
+ /* 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) /* v4 -> v6 is not possible */
- goto get_next_dst;
+ && 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);
+ 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
+ * Set those options that need to be set before establishing
+ * the connection. Reuse the address on passive (listening)
+ * sockets to avoid failure on restart.
*/
- /* 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));
+ 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);
}
close(sockfd);
goto get_next_src;
}
- if (!dst)
- break; /* bind-only completed successfully */
+ if (!dst) /* bind-only completed successfully */
+ break;
}
if (dst && connect(sockfd, dst->ai_addr, dst->ai_addrlen) == 0)
- break; /* connection completed successfully */
+ 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))
- dst = remote; /* restart inner loop */
+ if (src && (src = src->ai_next)) /* restart inner loop */
+ dst = remote;
}
if (local)
freeaddrinfo(local);
freeaddrinfo(remote);
if (src == NULL && dst == NULL) {
- PARA_ERROR_LOG("can not create %s socket %s#%s.\n", layer4_name(l4type),
- host? : (passive? "[loopback]" : "[localhost]"), port);
+ 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.
+ * \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)
return -ERRNO_TO_PARA_ERROR(errno);
}
PARA_INFO_LOG("listening on %s port %u, fd %d\n",
- layer4_name(l4type), port, fd);
+ 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)
+ * \param sa The IPv4/IPv6 socket address to use.
+ * \param len The length of \p sa.
+ *
+ * \sa getnameinfo(3).
*/
-char *host_and_port(struct sockaddr *sa, socklen_t len)
+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;
+ 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));
+ NI_NUMERICHOST | NI_NUMERICSERV);
+ if (ret) {
+ PARA_WARNING_LOG("hostname lookup error (%s).\n",
+ gai_strerror(ret));
sprintf(output, "(unknown)");
- } else {
+ } 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 \fn getsockname() for local, or \fn getpeername() for remote side.
*
- * \return A static character string identifying hostname and port of the chosen side
- * \sa getsockname(2), getpeername(2)
+ * \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 *))
+static char *__get_sock_name(int fd, int (*getname)(int, struct sockaddr*,
+ socklen_t *))
{
- struct sockaddr_storage ss;
- socklen_t sslen = sizeof(ss);
+ 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));
+ 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)
+char *local_name(int sockfd)
{
return __get_sock_name(sockfd, getsockname);
}
return __get_sock_name(sockfd, getpeername);
}
-/*
- * Send out a buffer, resend on short writes.
- *
- * \param fd The file descriptor.
- * \param buf The buffer to be sent.
- * \param len The length of \a buf.
+/**
+ * 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.
*
- * \return Standard. In any case, the number of bytes actually sent is stored
- * in \a len.
+ * \sa RFC 3493
*/
-static int sendall(int fd, const char *buf, size_t *len)
+struct in_addr extract_v4_addr(const struct sockaddr_storage *ss)
{
- size_t total = *len;
+ struct in_addr ia = {.s_addr = 0};
- assert(total);
- *len = 0;
- while (*len < total) {
- int ret = send(fd, buf + *len, total - *len, 0);
- if (ret == -1)
- return -ERRNO_TO_PARA_ERROR(errno);
- *len += ret;
+ 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 1;
+ return ia;
}
/**
crypt_function *cf = NULL;
if (!len)
- PARA_CRIT_LOG("%s", "len == 0\n");
+ PARA_CRIT_LOG("len == 0\n");
if (fd + 1 <= cda_size)
cf = crypt_data_array[fd].send;
if (cf) {
/* RC4 may write more than len to the output buffer */
unsigned char *outbuf = para_malloc(ROUND_UP(len, 8));
(*cf)(len, (unsigned char *)buf, outbuf, private);
- ret = sendall(fd, (char *)outbuf, &len);
+ ret = write_all(fd, (char *)outbuf, &len);
free(outbuf);
} else
- ret = sendall(fd, buf, &len);
+ ret = write_all(fd, buf, &len);
return ret;
}
}
/**
- * 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 The file descriptor, on success, negative on errors.
*
- * \sa create_local_socket(), unix(7), connect(2)
+ * \sa create_local_socket(), unix(7), connect(2).
*/
int create_remote_socket(const char *name)
{
}
#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 */
/**
- * 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.
*
- * This function creates a buffer of size \a bufsize and tries
- * to receive at most \a bufsize bytes from file descriptor \a fd.
- * If at least \p strlen(\a pattern) bytes were received, the beginning of
- * the received buffer is compared with \a pattern, ignoring case.
+ * This function tries to receive at most \a bufsize bytes from file descriptor
+ * \a fd. 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)
{
size_t len = strlen(pattern);
char *buf = para_malloc(bufsize + 1);
- int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize);
+ int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize + 1);
if (n < len)
goto out;
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);
}