diff options
author | Havoc Pennington <hp@redhat.com> | 2006-09-10 21:37:10 +0000 |
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committer | Havoc Pennington <hp@redhat.com> | 2006-09-10 21:37:10 +0000 |
commit | 8e659dac9fd5585c7b4ade836e09c22227d9ddc6 (patch) | |
tree | 577950f9656945ca56a6f8539fb02247c2d31fc5 /dbus/dbus-sysdeps-unix.c | |
parent | f61a63cefb4c931636b43ffa8f61ad3dd45d7b86 (diff) |
2006-09-10 Havoc Pennington <hp@redhat.com>
patch mostly by Peter Kümmel, bug #8211
* dbus/dbus-sysdeps-unix.c: new file, which splits out
unix-specific stuff in dbus-sysdeps.c
* dbus/dbus-sysdeps.c: don't include any UNIX-only headers,
and move unix-specific stuff to dbus-sysdeps-unix.c
* configure.in: check HAVE_ERRNO_H
Diffstat (limited to 'dbus/dbus-sysdeps-unix.c')
-rw-r--r-- | dbus/dbus-sysdeps-unix.c | 2172 |
1 files changed, 2172 insertions, 0 deletions
diff --git a/dbus/dbus-sysdeps-unix.c b/dbus/dbus-sysdeps-unix.c new file mode 100644 index 00000000..c40c5206 --- /dev/null +++ b/dbus/dbus-sysdeps-unix.c @@ -0,0 +1,2172 @@ +/* -*- mode: C; c-file-style: "gnu" -*- */ +/* dbus-sysdeps-unix.c Wrappers around UNIX system/libc features (internal to D-Bus implementation) + * + * Copyright (C) 2002, 2003, 2006 Red Hat, Inc. + * Copyright (C) 2003 CodeFactory AB + * + * Licensed under the Academic Free License version 2.1 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include "dbus-internals.h" +#include "dbus-sysdeps.h" +#include "dbus-threads.h" +#include "dbus-protocol.h" +#include "dbus-string.h" +#include <sys/types.h> +#include <stdlib.h> +#include <string.h> +#include <signal.h> +#include <unistd.h> +#include <stdio.h> +#include <fcntl.h> +#include <sys/socket.h> +#include <dirent.h> +#include <sys/un.h> +#include <pwd.h> +#include <time.h> +#include <locale.h> +#include <sys/time.h> +#include <sys/stat.h> +#include <sys/wait.h> +#include <netinet/in.h> +#include <netdb.h> +#include <grp.h> + +#ifdef HAVE_ERRNO_H +#include <errno.h> +#endif +#ifdef HAVE_WRITEV +#include <sys/uio.h> +#endif +#ifdef HAVE_POLL +#include <sys/poll.h> +#endif +#ifdef HAVE_BACKTRACE +#include <execinfo.h> +#endif +#ifdef HAVE_GETPEERUCRED +#include <ucred.h> +#endif + +#ifndef O_BINARY +#define O_BINARY 0 +#endif + +#ifndef HAVE_SOCKLEN_T +#define socklen_t int +#endif + +/** + * @addtogroup DBusInternalsUtils + * @{ + */ + +/** + * Thin wrapper around the read() system call that appends + * the data it reads to the DBusString buffer. It appends + * up to the given count, and returns the same value + * and same errno as read(). The only exception is that + * _dbus_read() handles EINTR for you. _dbus_read() can + * return ENOMEM, even though regular UNIX read doesn't. + * + * @param fd the file descriptor to read from + * @param buffer the buffer to append data to + * @param count the amount of data to read + * @returns the number of bytes read or -1 + */ +int +_dbus_read (int fd, + DBusString *buffer, + int count) +{ + int bytes_read; + int start; + char *data; + + _dbus_assert (count >= 0); + + start = _dbus_string_get_length (buffer); + + if (!_dbus_string_lengthen (buffer, count)) + { + errno = ENOMEM; + return -1; + } + + data = _dbus_string_get_data_len (buffer, start, count); + + again: + + bytes_read = read (fd, data, count); + + if (bytes_read < 0) + { + if (errno == EINTR) + goto again; + else + { + /* put length back (note that this doesn't actually realloc anything) */ + _dbus_string_set_length (buffer, start); + return -1; + } + } + else + { + /* put length back (doesn't actually realloc) */ + _dbus_string_set_length (buffer, start + bytes_read); + +#if 0 + if (bytes_read > 0) + _dbus_verbose_bytes_of_string (buffer, start, bytes_read); +#endif + + return bytes_read; + } +} + +/** + * Thin wrapper around the write() system call that writes a part of a + * DBusString and handles EINTR for you. + * + * @param fd the file descriptor to write + * @param buffer the buffer to write data from + * @param start the first byte in the buffer to write + * @param len the number of bytes to try to write + * @returns the number of bytes written or -1 on error + */ +int +_dbus_write (int fd, + const DBusString *buffer, + int start, + int len) +{ + const char *data; + int bytes_written; + + data = _dbus_string_get_const_data_len (buffer, start, len); + + again: + + bytes_written = write (fd, data, len); + + if (bytes_written < 0 && errno == EINTR) + goto again; + +#if 0 + if (bytes_written > 0) + _dbus_verbose_bytes_of_string (buffer, start, bytes_written); +#endif + + return bytes_written; +} + +/** + * Like _dbus_write() but will use writev() if possible + * to write both buffers in sequence. The return value + * is the number of bytes written in the first buffer, + * plus the number written in the second. If the first + * buffer is written successfully and an error occurs + * writing the second, the number of bytes in the first + * is returned (i.e. the error is ignored), on systems that + * don't have writev. Handles EINTR for you. + * The second buffer may be #NULL. + * + * @param fd the file descriptor + * @param buffer1 first buffer + * @param start1 first byte to write in first buffer + * @param len1 number of bytes to write from first buffer + * @param buffer2 second buffer, or #NULL + * @param start2 first byte to write in second buffer + * @param len2 number of bytes to write in second buffer + * @returns total bytes written from both buffers, or -1 on error + */ +int +_dbus_write_two (int fd, + const DBusString *buffer1, + int start1, + int len1, + const DBusString *buffer2, + int start2, + int len2) +{ + _dbus_assert (buffer1 != NULL); + _dbus_assert (start1 >= 0); + _dbus_assert (start2 >= 0); + _dbus_assert (len1 >= 0); + _dbus_assert (len2 >= 0); + +#ifdef HAVE_WRITEV + { + struct iovec vectors[2]; + const char *data1; + const char *data2; + int bytes_written; + + data1 = _dbus_string_get_const_data_len (buffer1, start1, len1); + + if (buffer2 != NULL) + data2 = _dbus_string_get_const_data_len (buffer2, start2, len2); + else + { + data2 = NULL; + start2 = 0; + len2 = 0; + } + + vectors[0].iov_base = (char*) data1; + vectors[0].iov_len = len1; + vectors[1].iov_base = (char*) data2; + vectors[1].iov_len = len2; + + again: + + bytes_written = writev (fd, + vectors, + data2 ? 2 : 1); + + if (bytes_written < 0 && errno == EINTR) + goto again; + + return bytes_written; + } +#else /* HAVE_WRITEV */ + { + int ret1; + + ret1 = _dbus_write (fd, buffer1, start1, len1); + if (ret1 == len1 && buffer2 != NULL) + { + ret2 = _dbus_write (fd, buffer2, start2, len2); + if (ret2 < 0) + ret2 = 0; /* we can't report an error as the first write was OK */ + + return ret1 + ret2; + } + else + return ret1; + } +#endif /* !HAVE_WRITEV */ +} + +#define _DBUS_MAX_SUN_PATH_LENGTH 99 + +/** + * @def _DBUS_MAX_SUN_PATH_LENGTH + * + * Maximum length of the path to a UNIX domain socket, + * sockaddr_un::sun_path member. POSIX requires that all systems + * support at least 100 bytes here, including the nul termination. + * We use 99 for the max value to allow for the nul. + * + * We could probably also do sizeof (addr.sun_path) + * but this way we are the same on all platforms + * which is probably a good idea. + */ + +/** + * Creates a socket and connects it to the UNIX domain socket at the + * given path. The connection fd is returned, and is set up as + * nonblocking. + * + * Uses abstract sockets instead of filesystem-linked sockets if + * requested (it's possible only on Linux; see "man 7 unix" on Linux). + * On non-Linux abstract socket usage always fails. + * + * @param path the path to UNIX domain socket + * @param abstract #TRUE to use abstract namespace + * @param error return location for error code + * @returns connection file descriptor or -1 on error + */ +int +_dbus_connect_unix_socket (const char *path, + dbus_bool_t abstract, + DBusError *error) +{ + int fd; + size_t path_len; + struct sockaddr_un addr; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + _dbus_verbose ("connecting to unix socket %s abstract=%d\n", + path, abstract); + + fd = socket (PF_UNIX, SOCK_STREAM, 0); + + if (fd < 0) + { + dbus_set_error (error, + _dbus_error_from_errno (errno), + "Failed to create socket: %s", + _dbus_strerror (errno)); + + return -1; + } + + _DBUS_ZERO (addr); + addr.sun_family = AF_UNIX; + path_len = strlen (path); + + if (abstract) + { +#ifdef HAVE_ABSTRACT_SOCKETS + addr.sun_path[0] = '\0'; /* this is what says "use abstract" */ + path_len++; /* Account for the extra nul byte added to the start of sun_path */ + + if (path_len > _DBUS_MAX_SUN_PATH_LENGTH) + { + dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS, + "Abstract socket name too long\n"); + _dbus_close (fd, NULL); + return -1; + } + + strncpy (&addr.sun_path[1], path, path_len); + /* _dbus_verbose_bytes (addr.sun_path, sizeof (addr.sun_path)); */ +#else /* HAVE_ABSTRACT_SOCKETS */ + dbus_set_error (error, DBUS_ERROR_NOT_SUPPORTED, + "Operating system does not support abstract socket namespace\n"); + _dbus_close (fd, NULL); + return -1; +#endif /* ! HAVE_ABSTRACT_SOCKETS */ + } + else + { + if (path_len > _DBUS_MAX_SUN_PATH_LENGTH) + { + dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS, + "Socket name too long\n"); + _dbus_close (fd, NULL); + return -1; + } + + strncpy (addr.sun_path, path, path_len); + } + + if (connect (fd, (struct sockaddr*) &addr, _DBUS_STRUCT_OFFSET (struct sockaddr_un, sun_path) + path_len) < 0) + { + dbus_set_error (error, + _dbus_error_from_errno (errno), + "Failed to connect to socket %s: %s", + path, _dbus_strerror (errno)); + + _dbus_close (fd, NULL); + fd = -1; + + return -1; + } + + if (!_dbus_set_fd_nonblocking (fd, error)) + { + _DBUS_ASSERT_ERROR_IS_SET (error); + + _dbus_close (fd, NULL); + fd = -1; + + return -1; + } + + return fd; +} + +/** + * Creates a socket and binds it to the given path, + * then listens on the socket. The socket is + * set to be nonblocking. + * + * Uses abstract sockets instead of filesystem-linked + * sockets if requested (it's possible only on Linux; + * see "man 7 unix" on Linux). + * On non-Linux abstract socket usage always fails. + * + * @param path the socket name + * @param abstract #TRUE to use abstract namespace + * @param error return location for errors + * @returns the listening file descriptor or -1 on error + */ +int +_dbus_listen_unix_socket (const char *path, + dbus_bool_t abstract, + DBusError *error) +{ + int listen_fd; + struct sockaddr_un addr; + size_t path_len; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + _dbus_verbose ("listening on unix socket %s abstract=%d\n", + path, abstract); + + listen_fd = socket (PF_UNIX, SOCK_STREAM, 0); + + if (listen_fd < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to create socket \"%s\": %s", + path, _dbus_strerror (errno)); + return -1; + } + + _DBUS_ZERO (addr); + addr.sun_family = AF_UNIX; + path_len = strlen (path); + + if (abstract) + { +#ifdef HAVE_ABSTRACT_SOCKETS + /* remember that abstract names aren't nul-terminated so we rely + * on sun_path being filled in with zeroes above. + */ + addr.sun_path[0] = '\0'; /* this is what says "use abstract" */ + path_len++; /* Account for the extra nul byte added to the start of sun_path */ + + if (path_len > _DBUS_MAX_SUN_PATH_LENGTH) + { + dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS, + "Abstract socket name too long\n"); + _dbus_close (listen_fd, NULL); + return -1; + } + + strncpy (&addr.sun_path[1], path, path_len); + /* _dbus_verbose_bytes (addr.sun_path, sizeof (addr.sun_path)); */ +#else /* HAVE_ABSTRACT_SOCKETS */ + dbus_set_error (error, DBUS_ERROR_NOT_SUPPORTED, + "Operating system does not support abstract socket namespace\n"); + _dbus_close (listen_fd, NULL); + return -1; +#endif /* ! HAVE_ABSTRACT_SOCKETS */ + } + else + { + /* FIXME discussed security implications of this with Nalin, + * and we couldn't think of where it would kick our ass, but + * it still seems a bit sucky. It also has non-security suckage; + * really we'd prefer to exit if the socket is already in use. + * But there doesn't seem to be a good way to do this. + * + * Just to be extra careful, I threw in the stat() - clearly + * the stat() can't *fix* any security issue, but it at least + * avoids inadvertent/accidental data loss. + */ + { + struct stat sb; + + if (stat (path, &sb) == 0 && + S_ISSOCK (sb.st_mode)) + unlink (path); + } + + if (path_len > _DBUS_MAX_SUN_PATH_LENGTH) + { + dbus_set_error (error, DBUS_ERROR_BAD_ADDRESS, + "Abstract socket name too long\n"); + _dbus_close (listen_fd, NULL); + return -1; + } + + strncpy (addr.sun_path, path, path_len); + } + + if (bind (listen_fd, (struct sockaddr*) &addr, _DBUS_STRUCT_OFFSET (struct sockaddr_un, sun_path) + path_len) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to bind socket \"%s\": %s", + path, _dbus_strerror (errno)); + _dbus_close (listen_fd, NULL); + return -1; + } + + if (listen (listen_fd, 30 /* backlog */) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to listen on socket \"%s\": %s", + path, _dbus_strerror (errno)); + _dbus_close (listen_fd, NULL); + return -1; + } + + if (!_dbus_set_fd_nonblocking (listen_fd, error)) + { + _DBUS_ASSERT_ERROR_IS_SET (error); + _dbus_close (listen_fd, NULL); + return -1; + } + + /* Try opening up the permissions, but if we can't, just go ahead + * and continue, maybe it will be good enough. + */ + if (!abstract && chmod (path, 0777) < 0) + _dbus_warn ("Could not set mode 0777 on socket %s\n", + path); + + return listen_fd; +} + +/** + * Creates a socket and connects to a socket at the given host + * and port. The connection fd is returned, and is set up as + * nonblocking. + * + * @param host the host name to connect to + * @param port the prot to connect to + * @param error return location for error code + * @returns connection file descriptor or -1 on error + */ +int +_dbus_connect_tcp_socket (const char *host, + dbus_uint32_t port, + DBusError *error) +{ + int fd; + struct sockaddr_in addr; + struct hostent *he; + struct in_addr *haddr; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + fd = socket (AF_INET, SOCK_STREAM, 0); + + if (fd < 0) + { + dbus_set_error (error, + _dbus_error_from_errno (errno), + "Failed to create socket: %s", + _dbus_strerror (errno)); + + return -1; + } + + if (host == NULL) + host = "localhost"; + + he = gethostbyname (host); + if (he == NULL) + { + dbus_set_error (error, + _dbus_error_from_errno (errno), + "Failed to lookup hostname: %s", + host); + _dbus_close (fd, NULL); + return -1; + } + + haddr = ((struct in_addr *) (he->h_addr_list)[0]); + + _DBUS_ZERO (addr); + memcpy (&addr.sin_addr, haddr, sizeof(struct in_addr)); + addr.sin_family = AF_INET; + addr.sin_port = htons (port); + + if (connect (fd, (struct sockaddr*) &addr, sizeof (addr)) < 0) + { + dbus_set_error (error, + _dbus_error_from_errno (errno), + "Failed to connect to socket %s:%d %s", + host, port, _dbus_strerror (errno)); + + _dbus_close (fd, NULL); + fd = -1; + + return -1; + } + + if (!_dbus_set_fd_nonblocking (fd, error)) + { + _dbus_close (fd, NULL); + fd = -1; + + return -1; + } + + return fd; +} + +/** + * Creates a socket and binds it to the given path, + * then listens on the socket. The socket is + * set to be nonblocking. + * + * @param host the host name to listen on + * @param port the prot to listen on + * @param error return location for errors + * @returns the listening file descriptor or -1 on error + */ +int +_dbus_listen_tcp_socket (const char *host, + dbus_uint32_t port, + DBusError *error) +{ + int listen_fd; + struct sockaddr_in addr; + struct hostent *he; + struct in_addr *haddr; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + listen_fd = socket (AF_INET, SOCK_STREAM, 0); + + if (listen_fd < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to create socket \"%s:%d\": %s", + host, port, _dbus_strerror (errno)); + return -1; + } + + he = gethostbyname (host); + if (he == NULL) + { + dbus_set_error (error, + _dbus_error_from_errno (errno), + "Failed to lookup hostname: %s", + host); + _dbus_close (listen_fd, NULL); + return -1; + } + + haddr = ((struct in_addr *) (he->h_addr_list)[0]); + + _DBUS_ZERO (addr); + memcpy (&addr.sin_addr, haddr, sizeof (struct in_addr)); + addr.sin_family = AF_INET; + addr.sin_port = htons (port); + + if (bind (listen_fd, (struct sockaddr*) &addr, sizeof (struct sockaddr))) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to bind socket \"%s:%d\": %s", + host, port, _dbus_strerror (errno)); + _dbus_close (listen_fd, NULL); + return -1; + } + + if (listen (listen_fd, 30 /* backlog */) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to listen on socket \"%s:%d\": %s", + host, port, _dbus_strerror (errno)); + _dbus_close (listen_fd, NULL); + return -1; + } + + if (!_dbus_set_fd_nonblocking (listen_fd, error)) + { + _dbus_close (listen_fd, NULL); + return -1; + } + + return listen_fd; +} + +static dbus_bool_t +write_credentials_byte (int server_fd, + DBusError *error) +{ + int bytes_written; + char buf[1] = { '\0' }; +#if defined(HAVE_CMSGCRED) && !defined(LOCAL_CREDS) + struct { + struct cmsghdr hdr; + struct cmsgcred cred; + } cmsg; + struct iovec iov; + struct msghdr msg; +#endif + +#if defined(HAVE_CMSGCRED) && !defined(LOCAL_CREDS) + iov.iov_base = buf; + iov.iov_len = 1; + + memset (&msg, 0, sizeof (msg)); + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + + msg.msg_control = &cmsg; + msg.msg_controllen = sizeof (cmsg); + memset (&cmsg, 0, sizeof (cmsg)); + cmsg.hdr.cmsg_len = sizeof (cmsg); + cmsg.hdr.cmsg_level = SOL_SOCKET; + cmsg.hdr.cmsg_type = SCM_CREDS; +#endif + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + again: + +#if defined(HAVE_CMSGCRED) && !defined(LOCAL_CREDS) + bytes_written = sendmsg (server_fd, &msg, 0); +#else + bytes_written = write (server_fd, buf, 1); +#endif + + if (bytes_written < 0 && errno == EINTR) + goto again; + + if (bytes_written < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to write credentials byte: %s", + _dbus_strerror (errno)); + return FALSE; + } + else if (bytes_written == 0) + { + dbus_set_error (error, DBUS_ERROR_IO_ERROR, + "wrote zero bytes writing credentials byte"); + return FALSE; + } + else + { + _dbus_assert (bytes_written == 1); + _dbus_verbose ("wrote credentials byte\n"); + return TRUE; + } +} + +/** + * Reads a single byte which must be nul (an error occurs otherwise), + * and reads unix credentials if available. Fills in pid/uid/gid with + * -1 if no credentials are available. Return value indicates whether + * a byte was read, not whether we got valid credentials. On some + * systems, such as Linux, reading/writing the byte isn't actually + * required, but we do it anyway just to avoid multiple codepaths. + * + * Fails if no byte is available, so you must select() first. + * + * The point of the byte is that on some systems we have to + * use sendmsg()/recvmsg() to transmit credentials. + * + * @param client_fd the client file descriptor + * @param credentials struct to fill with credentials of client + * @param error location to store error code + * @returns #TRUE on success + */ +dbus_bool_t +_dbus_read_credentials_unix_socket (int client_fd, + DBusCredentials *credentials, + DBusError *error) +{ + struct msghdr msg; + struct iovec iov; + char buf; + +#ifdef HAVE_CMSGCRED + struct { + struct cmsghdr hdr; + struct cmsgcred cred; + } cmsg; +#endif + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + /* The POSIX spec certainly doesn't promise this, but + * we need these assertions to fail as soon as we're wrong about + * it so we can do the porting fixups + */ + _dbus_assert (sizeof (pid_t) <= sizeof (credentials->pid)); + _dbus_assert (sizeof (uid_t) <= sizeof (credentials->uid)); + _dbus_assert (sizeof (gid_t) <= sizeof (credentials->gid)); + + _dbus_credentials_clear (credentials); + +#if defined(LOCAL_CREDS) && defined(HAVE_CMSGCRED) + /* Set the socket to receive credentials on the next message */ + { + int on = 1; + if (setsockopt (client_fd, 0, LOCAL_CREDS, &on, sizeof (on)) < 0) + { + _dbus_verbose ("Unable to set LOCAL_CREDS socket option\n"); + return FALSE; + } + } +#endif + + iov.iov_base = &buf; + iov.iov_len = 1; + + memset (&msg, 0, sizeof (msg)); + msg.msg_iov = &iov; + msg.msg_iovlen = 1; + +#ifdef HAVE_CMSGCRED + memset (&cmsg, 0, sizeof (cmsg)); + msg.msg_control = &cmsg; + msg.msg_controllen = sizeof (cmsg); +#endif + + again: + if (recvmsg (client_fd, &msg, 0) < 0) + { + if (errno == EINTR) + goto again; + + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to read credentials byte: %s", + _dbus_strerror (errno)); + return FALSE; + } + + if (buf != '\0') + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "Credentials byte was not nul"); + return FALSE; + } + +#ifdef HAVE_CMSGCRED + if (cmsg.hdr.cmsg_len < sizeof (cmsg) || cmsg.hdr.cmsg_type != SCM_CREDS) + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "Message from recvmsg() was not SCM_CREDS"); + return FALSE; + } +#endif + + _dbus_verbose ("read credentials byte\n"); + + { +#ifdef SO_PEERCRED + struct ucred cr; + int cr_len = sizeof (cr); + + if (getsockopt (client_fd, SOL_SOCKET, SO_PEERCRED, &cr, &cr_len) == 0 && + cr_len == sizeof (cr)) + { + credentials->pid = cr.pid; + credentials->uid = cr.uid; + credentials->gid = cr.gid; + } + else + { + _dbus_verbose ("Failed to getsockopt() credentials, returned len %d/%d: %s\n", + cr_len, (int) sizeof (cr), _dbus_strerror (errno)); + } +#elif defined(HAVE_CMSGCRED) + credentials->pid = cmsg.cred.cmcred_pid; + credentials->uid = cmsg.cred.cmcred_euid; + credentials->gid = cmsg.cred.cmcred_groups[0]; +#elif defined(HAVE_GETPEEREID) + uid_t euid; + gid_t egid; + if (getpeereid (client_fd, &euid, &egid) == 0) + { + credentials->uid = euid; + credentials->gid = egid; + } + else + { + _dbus_verbose ("Failed to getpeereid() credentials: %s\n", _dbus_strerror (errno)); + } +#elif defined(HAVE_GETPEERUCRED) + ucred_t * ucred = NULL; + if (getpeerucred (client_fd, &ucred) == 0) + { + credentials->pid = ucred_getpid (ucred); + credentials->uid = ucred_geteuid (ucred); + credentials->gid = ucred_getegid (ucred); + } + else + { + _dbus_verbose ("Failed to getpeerucred() credentials: %s\n", _dbus_strerror (errno)); + } + if (ucred != NULL) + ucred_free (ucred); +#else /* !SO_PEERCRED && !HAVE_CMSGCRED && !HAVE_GETPEEREID && !HAVE_GETPEERUCRED */ + _dbus_verbose ("Socket credentials not supported on this OS\n"); +#endif + } + + _dbus_verbose ("Credentials:" + " pid "DBUS_PID_FORMAT + " uid "DBUS_UID_FORMAT + " gid "DBUS_GID_FORMAT"\n", + credentials->pid, + credentials->uid, + credentials->gid); + + return TRUE; +} + +/** + * Sends a single nul byte with our UNIX credentials as ancillary + * data. Returns #TRUE if the data was successfully written. On + * systems that don't support sending credentials, just writes a byte, + * doesn't send any credentials. On some systems, such as Linux, + * reading/writing the byte isn't actually required, but we do it + * anyway just to avoid multiple codepaths. + * + * Fails if no byte can be written, so you must select() first. + * + * The point of the byte is that on some systems we have to + * use sendmsg()/recvmsg() to transmit credentials. + * + * @param server_fd file descriptor for connection to server + * @param error return location for error code + * @returns #TRUE if the byte was sent + */ +dbus_bool_t +_dbus_send_credentials_unix_socket (int server_fd, + DBusError *error) +{ + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + if (write_credentials_byte (server_fd, error)) + return TRUE; + else + return FALSE; +} + +/** + * Accepts a connection on a listening socket. + * Handles EINTR for you. + * + * @param listen_fd the listen file descriptor + * @returns the connection fd of the client, or -1 on error + */ +int +_dbus_accept (int listen_fd) +{ + int client_fd; + struct sockaddr addr; + socklen_t addrlen; + + addrlen = sizeof (addr); + + retry: + client_fd = accept (listen_fd, &addr, &addrlen); + + if (client_fd < 0) + { + if (errno == EINTR) + goto retry; + } + + return client_fd; +} + +/** + * Checks to make sure the given directory is + * private to the user + * + * @param dir the name of the directory + * @param error error return + * @returns #FALSE on failure + **/ +dbus_bool_t +_dbus_check_dir_is_private_to_user (DBusString *dir, DBusError *error) +{ + const char *directory; + struct stat sb; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + directory = _dbus_string_get_const_data (dir); + + if (stat (directory, &sb) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "%s", _dbus_strerror (errno)); + + return FALSE; + } + + if ((S_IROTH & sb.st_mode) || (S_IWOTH & sb.st_mode) || + (S_IRGRP & sb.st_mode) || (S_IWGRP & sb.st_mode)) + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "%s directory is not private to the user", directory); + return FALSE; + } + + return TRUE; +} + +static dbus_bool_t +fill_user_info_from_passwd (struct passwd *p, + DBusUserInfo *info, + DBusError *error) +{ + _dbus_assert (p->pw_name != NULL); + _dbus_assert (p->pw_dir != NULL); + + info->uid = p->pw_uid; + info->primary_gid = p->pw_gid; + info->username = _dbus_strdup (p->pw_name); + info->homedir = _dbus_strdup (p->pw_dir); + + if (info->username == NULL || + info->homedir == NULL) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + return FALSE; + } + + return TRUE; +} + +static dbus_bool_t +fill_user_info (DBusUserInfo *info, + dbus_uid_t uid, + const DBusString *username, + DBusError *error) +{ + const char *username_c; + + /* exactly one of username/uid provided */ + _dbus_assert (username != NULL || uid != DBUS_UID_UNSET); + _dbus_assert (username == NULL || uid == DBUS_UID_UNSET); + + info->uid = DBUS_UID_UNSET; + info->primary_gid = DBUS_GID_UNSET; + info->group_ids = NULL; + info->n_group_ids = 0; + info->username = NULL; + info->homedir = NULL; + + if (username != NULL) + username_c = _dbus_string_get_const_data (username); + else + username_c = NULL; + + /* For now assuming that the getpwnam() and getpwuid() flavors + * are always symmetrical, if not we have to add more configure + * checks + */ + +#if defined (HAVE_POSIX_GETPWNAM_R) || defined (HAVE_NONPOSIX_GETPWNAM_R) + { + struct passwd *p; + int result; + char buf[1024]; + struct passwd p_str; + + p = NULL; +#ifdef HAVE_POSIX_GETPWNAM_R + if (uid != DBUS_UID_UNSET) + result = getpwuid_r (uid, &p_str, buf, sizeof (buf), + &p); + else + result = getpwnam_r (username_c, &p_str, buf, sizeof (buf), + &p); +#else + if (uid != DBUS_UID_UNSET) + p = getpwuid_r (uid, &p_str, buf, sizeof (buf)); + else + p = getpwnam_r (username_c, &p_str, buf, sizeof (buf)); + result = 0; +#endif /* !HAVE_POSIX_GETPWNAM_R */ + if (result == 0 && p == &p_str) + { + if (!fill_user_info_from_passwd (p, info, error)) + return FALSE; + } + else + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "User \"%s\" unknown or no memory to allocate password entry\n", + username_c ? username_c : "???"); + _dbus_verbose ("User %s unknown\n", username_c ? username_c : "???"); + return FALSE; + } + } +#else /* ! HAVE_GETPWNAM_R */ + { + /* I guess we're screwed on thread safety here */ + struct passwd *p; + + if (uid != DBUS_UID_UNSET) + p = getpwuid (uid); + else + p = getpwnam (username_c); + + if (p != NULL) + { + if (!fill_user_info_from_passwd (p, info, error)) + return FALSE; + } + else + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "User \"%s\" unknown or no memory to allocate password entry\n", + username_c ? username_c : "???"); + _dbus_verbose ("User %s unknown\n", username_c ? username_c : "???"); + return FALSE; + } + } +#endif /* ! HAVE_GETPWNAM_R */ + + /* Fill this in so we can use it to get groups */ + username_c = info->username; + +#ifdef HAVE_GETGROUPLIST + { + gid_t *buf; + int buf_count; + int i; + + buf_count = 17; + buf = dbus_new (gid_t, buf_count); + if (buf == NULL) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + goto failed; + } + + if (getgrouplist (username_c, + info->primary_gid, + buf, &buf_count) < 0) + { + gid_t *new = dbus_realloc (buf, buf_count * sizeof (buf[0])); + if (new == NULL) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + dbus_free (buf); + goto failed; + } + + buf = new; + + errno = 0; + if (getgrouplist (username_c, info->primary_gid, buf, &buf_count) < 0) + { + dbus_set_error (error, + _dbus_error_from_errno (errno), + "Failed to get groups for username \"%s\" primary GID " + DBUS_GID_FORMAT ": %s\n", + username_c, info->primary_gid, + _dbus_strerror (errno)); + dbus_free (buf); + goto failed; + } + } + + info->group_ids = dbus_new (dbus_gid_t, buf_count); + if (info->group_ids == NULL) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + dbus_free (buf); + goto failed; + } + + for (i = 0; i < buf_count; ++i) + info->group_ids[i] = buf[i]; + + info->n_group_ids = buf_count; + + dbus_free (buf); + } +#else /* HAVE_GETGROUPLIST */ + { + /* We just get the one group ID */ + info->group_ids = dbus_new (dbus_gid_t, 1); + if (info->group_ids == NULL) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + goto failed; + } + + info->n_group_ids = 1; + + (info->group_ids)[0] = info->primary_gid; + } +#endif /* HAVE_GETGROUPLIST */ + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + return TRUE; + + failed: + _DBUS_ASSERT_ERROR_IS_SET (error); + return FALSE; +} + +/** + * Gets user info for the given username. + * + * @param info user info object to initialize + * @param username the username + * @param error error return + * @returns #TRUE on success + */ +dbus_bool_t +_dbus_user_info_fill (DBusUserInfo *info, + const DBusString *username, + DBusError *error) +{ + return fill_user_info (info, DBUS_UID_UNSET, + username, error); +} + +/** + * Gets user info for the given user ID. + * + * @param info user info object to initialize + * @param uid the user ID + * @param error error return + * @returns #TRUE on success + */ +dbus_bool_t +_dbus_user_info_fill_uid (DBusUserInfo *info, + dbus_uid_t uid, + DBusError *error) +{ + return fill_user_info (info, uid, + NULL, error); +} + +/** + * Gets the credentials of the current process. + * + * @param credentials credentials to fill in. + */ +void +_dbus_credentials_from_current_process (DBusCredentials *credentials) +{ + /* The POSIX spec certainly doesn't promise this, but + * we need these assertions to fail as soon as we're wrong about + * it so we can do the porting fixups + */ + _dbus_assert (sizeof (pid_t) <= sizeof (credentials->pid)); + _dbus_assert (sizeof (uid_t) <= sizeof (credentials->uid)); + _dbus_assert (sizeof (gid_t) <= sizeof (credentials->gid)); + + credentials->pid = getpid (); + credentials->uid = getuid (); + credentials->gid = getgid (); +} + +/** + * Gets our process ID + * @returns process ID + */ +unsigned long +_dbus_getpid (void) +{ + return getpid (); +} + +/** Gets our UID + * @returns process UID + */ +dbus_uid_t +_dbus_getuid (void) +{ + return getuid (); +} + +#ifdef DBUS_BUILD_TESTS +/** Gets our GID + * @returns process GID + */ +dbus_gid_t +_dbus_getgid (void) +{ + return getgid (); +} +#endif + +/** + * Wrapper for poll(). + * + * @param fds the file descriptors to poll + * @param n_fds number of descriptors in the array + * @param timeout_milliseconds timeout or -1 for infinite + * @returns numbers of fds with revents, or <0 on error + */ +int +_dbus_poll (DBusPollFD *fds, + int n_fds, + int timeout_milliseconds) +{ +#ifdef HAVE_POLL + /* This big thing is a constant expression and should get optimized + * out of existence. So it's more robust than a configure check at + * no cost. + */ + if (_DBUS_POLLIN == POLLIN && + _DBUS_POLLPRI == POLLPRI && + _DBUS_POLLOUT == POLLOUT && + _DBUS_POLLERR == POLLERR && + _DBUS_POLLHUP == POLLHUP && + _DBUS_POLLNVAL == POLLNVAL && + sizeof (DBusPollFD) == sizeof (struct pollfd) && + _DBUS_STRUCT_OFFSET (DBusPollFD, fd) == + _DBUS_STRUCT_OFFSET (struct pollfd, fd) && + _DBUS_STRUCT_OFFSET (DBusPollFD, events) == + _DBUS_STRUCT_OFFSET (struct pollfd, events) && + _DBUS_STRUCT_OFFSET (DBusPollFD, revents) == + _DBUS_STRUCT_OFFSET (struct pollfd, revents)) + { + return poll ((struct pollfd*) fds, + n_fds, + timeout_milliseconds); + } + else + { + /* We have to convert the DBusPollFD to an array of + * struct pollfd, poll, and convert back. + */ + _dbus_warn ("didn't implement poll() properly for this system yet\n"); + return -1; + } +#else /* ! HAVE_POLL */ + + fd_set read_set, write_set, err_set; + int max_fd = 0; + int i; + struct timeval tv; + int ready; + + FD_ZERO (&read_set); + FD_ZERO (&write_set); + FD_ZERO (&err_set); + + for (i = 0; i < n_fds; i++) + { + DBusPollFD *fdp = &fds[i]; + + if (fdp->events & _DBUS_POLLIN) + FD_SET (fdp->fd, &read_set); + + if (fdp->events & _DBUS_POLLOUT) + FD_SET (fdp->fd, &write_set); + + FD_SET (fdp->fd, &err_set); + + max_fd = MAX (max_fd, fdp->fd); + } + + tv.tv_sec = timeout_milliseconds / 1000; + tv.tv_usec = (timeout_milliseconds % 1000) * 1000; + + ready = select (max_fd + 1, &read_set, &write_set, &err_set, + timeout_milliseconds < 0 ? NULL : &tv); + + if (ready > 0) + { + for (i = 0; i < n_fds; i++) + { + DBusPollFD *fdp = &fds[i]; + + fdp->revents = 0; + + if (FD_ISSET (fdp->fd, &read_set)) + fdp->revents |= _DBUS_POLLIN; + + if (FD_ISSET (fdp->fd, &write_set)) + fdp->revents |= _DBUS_POLLOUT; + + if (FD_ISSET (fdp->fd, &err_set)) + fdp->revents |= _DBUS_POLLERR; + } + } + + return ready; +#endif +} + +/** + * Get current time, as in gettimeofday(). + * + * @param tv_sec return location for number of seconds + * @param tv_usec return location for number of microseconds (thousandths) + */ +void +_dbus_get_current_time (long *tv_sec, + long *tv_usec) +{ + struct timeval t; + + gettimeofday (&t, NULL); + + if (tv_sec) + *tv_sec = t.tv_sec; + if (tv_usec) + *tv_usec = t.tv_usec; +} + +/** + * Appends the contents of the given file to the string, + * returning error code. At the moment, won't open a file + * more than a megabyte in size. + * + * @param str the string to append to + * @param filename filename to load + * @param error place to set an error + * @returns #FALSE if error was set + */ +dbus_bool_t +_dbus_file_get_contents (DBusString *str, + const DBusString *filename, + DBusError *error) +{ + int fd; + struct stat sb; + int orig_len; + int total; + const char *filename_c; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + filename_c = _dbus_string_get_const_data (filename); + + /* O_BINARY useful on Cygwin */ + fd = open (filename_c, O_RDONLY | O_BINARY); + if (fd < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to open \"%s\": %s", + filename_c, + _dbus_strerror (errno)); + return FALSE; + } + + if (fstat (fd, &sb) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to stat \"%s\": %s", + filename_c, + _dbus_strerror (errno)); + + _dbus_verbose ("fstat() failed: %s", + _dbus_strerror (errno)); + + _dbus_close (fd, NULL); + + return FALSE; + } + + if (sb.st_size > _DBUS_ONE_MEGABYTE) + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "File size %lu of \"%s\" is too large.", + (unsigned long) sb.st_size, filename_c); + _dbus_close (fd, NULL); + return FALSE; + } + + total = 0; + orig_len = _dbus_string_get_length (str); + if (sb.st_size > 0 && S_ISREG (sb.st_mode)) + { + int bytes_read; + + while (total < (int) sb.st_size) + { + bytes_read = _dbus_read (fd, str, + sb.st_size - total); + if (bytes_read <= 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Error reading \"%s\": %s", + filename_c, + _dbus_strerror (errno)); + + _dbus_verbose ("read() failed: %s", + _dbus_strerror (errno)); + + _dbus_close (fd, NULL); + _dbus_string_set_length (str, orig_len); + return FALSE; + } + else + total += bytes_read; + } + + _dbus_close (fd, NULL); + return TRUE; + } + else if (sb.st_size != 0) + { + _dbus_verbose ("Can only open regular files at the moment.\n"); + dbus_set_error (error, DBUS_ERROR_FAILED, + "\"%s\" is not a regular file", + filename_c); + _dbus_close (fd, NULL); + return FALSE; + } + else + { + _dbus_close (fd, NULL); + return TRUE; + } +} + +/** + * Writes a string out to a file. If the file exists, + * it will be atomically overwritten by the new data. + * + * @param str the string to write out + * @param filename the file to save string to + * @param error error to be filled in on failure + * @returns #FALSE on failure + */ +dbus_bool_t +_dbus_string_save_to_file (const DBusString *str, + const DBusString *filename, + DBusError *error) +{ + int fd; + int bytes_to_write; + const char *filename_c; + DBusString tmp_filename; + const char *tmp_filename_c; + int total; + dbus_bool_t need_unlink; + dbus_bool_t retval; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + fd = -1; + retval = FALSE; + need_unlink = FALSE; + + if (!_dbus_string_init (&tmp_filename)) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + return FALSE; + } + + if (!_dbus_string_copy (filename, 0, &tmp_filename, 0)) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + _dbus_string_free (&tmp_filename); + return FALSE; + } + + if (!_dbus_string_append (&tmp_filename, ".")) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + _dbus_string_free (&tmp_filename); + return FALSE; + } + +#define N_TMP_FILENAME_RANDOM_BYTES 8 + if (!_dbus_generate_random_ascii (&tmp_filename, N_TMP_FILENAME_RANDOM_BYTES)) + { + dbus_set_error (error, DBUS_ERROR_NO_MEMORY, NULL); + _dbus_string_free (&tmp_filename); + return FALSE; + } + + filename_c = _dbus_string_get_const_data (filename); + tmp_filename_c = _dbus_string_get_const_data (&tmp_filename); + + fd = open (tmp_filename_c, O_WRONLY | O_BINARY | O_EXCL | O_CREAT, + 0600); + if (fd < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Could not create %s: %s", tmp_filename_c, + _dbus_strerror (errno)); + goto out; + } + + need_unlink = TRUE; + + total = 0; + bytes_to_write = _dbus_string_get_length (str); + + while (total < bytes_to_write) + { + int bytes_written; + + bytes_written = _dbus_write (fd, str, total, + bytes_to_write - total); + + if (bytes_written <= 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Could not write to %s: %s", tmp_filename_c, + _dbus_strerror (errno)); + + goto out; + } + + total += bytes_written; + } + + if (!_dbus_close (fd, NULL)) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Could not close file %s: %s", + tmp_filename_c, _dbus_strerror (errno)); + + goto out; + } + + fd = -1; + + if (rename (tmp_filename_c, filename_c) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Could not rename %s to %s: %s", + tmp_filename_c, filename_c, + _dbus_strerror (errno)); + + goto out; + } + + need_unlink = FALSE; + + retval = TRUE; + + out: + /* close first, then unlink, to prevent ".nfs34234235" garbage + * files + */ + + if (fd >= 0) + _dbus_close (fd, NULL); + + if (need_unlink && unlink (tmp_filename_c) < 0) + _dbus_verbose ("Failed to unlink temp file %s: %s\n", + tmp_filename_c, _dbus_strerror (errno)); + + _dbus_string_free (&tmp_filename); + + if (!retval) + _DBUS_ASSERT_ERROR_IS_SET (error); + + return retval; +} + +/** Creates the given file, failing if the file already exists. + * + * @param filename the filename + * @param error error location + * @returns #TRUE if we created the file and it didn't exist + */ +dbus_bool_t +_dbus_create_file_exclusively (const DBusString *filename, + DBusError *error) +{ + int fd; + const char *filename_c; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + filename_c = _dbus_string_get_const_data (filename); + + fd = open (filename_c, O_WRONLY | O_BINARY | O_EXCL | O_CREAT, + 0600); + if (fd < 0) + { + dbus_set_error (error, + DBUS_ERROR_FAILED, + "Could not create file %s: %s\n", + filename_c, + _dbus_strerror (errno)); + return FALSE; + } + + if (!_dbus_close (fd, NULL)) + { + dbus_set_error (error, + DBUS_ERROR_FAILED, + "Could not close file %s: %s\n", + filename_c, + _dbus_strerror (errno)); + return FALSE; + } + + return TRUE; +} + +/** + * Deletes the given file. + * + * @param filename the filename + * @param error error location + * + * @returns #TRUE if unlink() succeeded + */ +dbus_bool_t +_dbus_delete_file (const DBusString *filename, + DBusError *error) +{ + const char *filename_c; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + filename_c = _dbus_string_get_const_data (filename); + + if (unlink (filename_c) < 0) + { + dbus_set_error (error, DBUS_ERROR_FAILED, + "Failed to delete file %s: %s\n", + filename_c, _dbus_strerror (errno)); + return FALSE; + } + else + return TRUE; +} + +/** + * Creates a directory; succeeds if the directory + * is created or already existed. + * + * @param filename directory filename + * @param error initialized error object + * @returns #TRUE on success + */ +dbus_bool_t +_dbus_create_directory (const DBusString *filename, + DBusError *error) +{ + const char *filename_c; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + filename_c = _dbus_string_get_const_data (filename); + + if (mkdir (filename_c, 0700) < 0) + { + if (errno == EEXIST) + return TRUE; + + dbus_set_error (error, DBUS_ERROR_FAILED, + "Failed to create directory %s: %s\n", + filename_c, _dbus_strerror (errno)); + return FALSE; + } + else + return TRUE; +} + +/** + * Appends the given filename to the given directory. + * + * @todo it might be cute to collapse multiple '/' such as "foo//" + * concat "//bar" + * + * @param dir the directory name + * @param next_component the filename + * @returns #TRUE on success + */ +dbus_bool_t +_dbus_concat_dir_and_file (DBusString *dir, + const DBusString *next_component) +{ + dbus_bool_t dir_ends_in_slash; + dbus_bool_t file_starts_with_slash; + + if (_dbus_string_get_length (dir) == 0 || + _dbus_string_get_length (next_component) == 0) + return TRUE; + + dir_ends_in_slash = '/' == _dbus_string_get_byte (dir, + _dbus_string_get_length (dir) - 1); + + file_starts_with_slash = '/' == _dbus_string_get_byte (next_component, 0); + + if (dir_ends_in_slash && file_starts_with_slash) + { + _dbus_string_shorten (dir, 1); + } + else if (!(dir_ends_in_slash || file_starts_with_slash)) + { + if (!_dbus_string_append_byte (dir, '/')) + return FALSE; + } + + return _dbus_string_copy (next_component, 0, dir, + _dbus_string_get_length (dir)); +} + +/** nanoseconds in a second */ +#define NANOSECONDS_PER_SECOND 1000000000 +/** microseconds in a second */ +#define MICROSECONDS_PER_SECOND 1000000 +/** milliseconds in a second */ +#define MILLISECONDS_PER_SECOND 1000 +/** nanoseconds in a millisecond */ +#define NANOSECONDS_PER_MILLISECOND 1000000 +/** microseconds in a millisecond */ +#define MICROSECONDS_PER_MILLISECOND 1000 + +/** + * Sleeps the given number of milliseconds. + * @param milliseconds number of milliseconds + */ +void +_dbus_sleep_milliseconds (int milliseconds) +{ +#ifdef HAVE_NANOSLEEP + struct timespec req; + struct timespec rem; + + req.tv_sec = milliseconds / MILLISECONDS_PER_SECOND; + req.tv_nsec = (milliseconds % MILLISECONDS_PER_SECOND) * NANOSECONDS_PER_MILLISECOND; + rem.tv_sec = 0; + rem.tv_nsec = 0; + + while (nanosleep (&req, &rem) < 0 && errno == EINTR) + req = rem; +#elif defined (HAVE_USLEEP) + usleep (milliseconds * MICROSECONDS_PER_MILLISECOND); +#else /* ! HAVE_USLEEP */ + sleep (MAX (milliseconds / 1000, 1)); +#endif +} + +static dbus_bool_t +_dbus_generate_pseudorandom_bytes (DBusString *str, + int n_bytes) +{ + int old_len; + char *p; + + old_len = _dbus_string_get_length (str); + + if (!_dbus_string_lengthen (str, n_bytes)) + return FALSE; + + p = _dbus_string_get_data_len (str, old_len, n_bytes); + + _dbus_generate_pseudorandom_bytes_buffer (p, n_bytes); + + return TRUE; +} + +/** + * Generates the given number of random bytes, + * using the best mechanism we can come up with. + * + * @param str the string + * @param n_bytes the number of random bytes to append to string + * @returns #TRUE on success, #FALSE if no memory + */ +dbus_bool_t +_dbus_generate_random_bytes (DBusString *str, + int n_bytes) +{ + int old_len; + int fd; + + /* FALSE return means "no memory", if it could + * mean something else then we'd need to return + * a DBusError. So we always fall back to pseudorandom + * if the I/O fails. + */ + + old_len = _dbus_string_get_length (str); + fd = -1; + + /* note, urandom on linux will fall back to pseudorandom */ + fd = open ("/dev/urandom", O_RDONLY); + if (fd < 0) + return _dbus_generate_pseudorandom_bytes (str, n_bytes); + + if (_dbus_read (fd, str, n_bytes) != n_bytes) + { + _dbus_close (fd, NULL); + _dbus_string_set_length (str, old_len); + return _dbus_generate_pseudorandom_bytes (str, n_bytes); + } + + _dbus_verbose ("Read %d bytes from /dev/urandom\n", + n_bytes); + + _dbus_close (fd, NULL); + + return TRUE; +} + +/** + * Exit the process, returning the given value. + * + * @param code the exit code + */ +void +_dbus_exit (int code) +{ + _exit (code); +} + +/** + * A wrapper around strerror() because some platforms + * may be lame and not have strerror(). + * + * @param error_number errno. + * @returns error description. + */ +const char* +_dbus_strerror (int error_number) +{ + const char *msg; + + msg = strerror (error_number); + if (msg == NULL) + msg = "unknown"; + + return msg; +} + +/** + * signal (SIGPIPE, SIG_IGN); + */ +void +_dbus_disable_sigpipe (void) +{ + signal (SIGPIPE, SIG_IGN); +} + +/** + * Sets the file descriptor to be close + * on exec. Should be called for all file + * descriptors in D-Bus code. + * + * @param fd the file descriptor + */ +void +_dbus_fd_set_close_on_exec (int fd) +{ + int val; + + val = fcntl (fd, F_GETFD, 0); + + if (val < 0) + return; + + val |= FD_CLOEXEC; + + fcntl (fd, F_SETFD, val); +} + +/** + * Closes a file descriptor. + * + * @param fd the file descriptor + * @param error error object + * @returns #FALSE if error set + */ +dbus_bool_t +_dbus_close (int fd, + DBusError *error) +{ + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + again: + if (close (fd) < 0) + { + if (errno == EINTR) + goto again; + + dbus_set_error (error, _dbus_error_from_errno (errno), + "Could not close fd %d", fd); + return FALSE; + } + + return TRUE; +} + +/** + * Sets a file descriptor to be nonblocking. + * + * @param fd the file descriptor. + * @param error address of error location. + * @returns #TRUE on success. + */ +dbus_bool_t +_dbus_set_fd_nonblocking (int fd, + DBusError *error) +{ + int val; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + val = fcntl (fd, F_GETFL, 0); + if (val < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to get flags from file descriptor %d: %s", + fd, _dbus_strerror (errno)); + _dbus_verbose ("Failed to get flags for fd %d: %s\n", fd, + _dbus_strerror (errno)); + return FALSE; + } + + if (fcntl (fd, F_SETFL, val | O_NONBLOCK) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Failed to set nonblocking flag of file descriptor %d: %s", + fd, _dbus_strerror (errno)); + _dbus_verbose ("Failed to set fd %d nonblocking: %s\n", + fd, _dbus_strerror (errno)); + + return FALSE; + } + + return TRUE; +} + +#if !defined (DBUS_DISABLE_ASSERT) || defined(DBUS_BUILD_TESTS) +/** + * On GNU libc systems, print a crude backtrace to the verbose log. + * On other systems, print "no backtrace support" + * + */ +void +_dbus_print_backtrace (void) +{ +#if defined (HAVE_BACKTRACE) && defined (DBUS_ENABLE_VERBOSE_MODE) + void *bt[500]; + int bt_size; + int i; + char **syms; + + bt_size = backtrace (bt, 500); + + syms = backtrace_symbols (bt, bt_size); + + i = 0; + while (i < bt_size) + { + _dbus_verbose (" %s\n", syms[i]); + ++i; + } + + free (syms); +#else + _dbus_verbose (" D-Bus not compiled with backtrace support\n"); +#endif +} +#endif /* asserts or tests enabled */ + +/** + * Creates a full-duplex pipe (as in socketpair()). + * Sets both ends of the pipe nonblocking. + * + * @todo libdbus only uses this for the debug-pipe server, so in + * principle it could be in dbus-sysdeps-util.c, except that + * dbus-sysdeps-util.c isn't in libdbus when tests are enabled and the + * debug-pipe server is used. + * + * @param fd1 return location for one end + * @param fd2 return location for the other end + * @param blocking #TRUE if pipe should be blocking + * @param error error return + * @returns #FALSE on failure (if error is set) + */ +dbus_bool_t +_dbus_full_duplex_pipe (int *fd1, + int *fd2, + dbus_bool_t blocking, + DBusError *error) +{ +#ifdef HAVE_SOCKETPAIR + int fds[2]; + + _DBUS_ASSERT_ERROR_IS_CLEAR (error); + + if (socketpair (AF_UNIX, SOCK_STREAM, 0, fds) < 0) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Could not create full-duplex pipe"); + return FALSE; + } + + if (!blocking && + (!_dbus_set_fd_nonblocking (fds[0], NULL) || + !_dbus_set_fd_nonblocking (fds[1], NULL))) + { + dbus_set_error (error, _dbus_error_from_errno (errno), + "Could not set full-duplex pipe nonblocking"); + + _dbus_close (fds[0], NULL); + _dbus_close (fds[1], NULL); + + return FALSE; + } + + *fd1 = fds[0]; + *fd2 = fds[1]; + + _dbus_verbose ("full-duplex pipe %d <-> %d\n", + *fd1, *fd2); + + return TRUE; +#else + _dbus_warn ("_dbus_full_duplex_pipe() not implemented on this OS\n"); + dbus_set_error (error, DBUS_ERROR_FAILED, + "_dbus_full_duplex_pipe() not implemented on this OS"); + return FALSE; +#endif +} + + +/** + * Measure the length of the given format string and arguments, + * not including the terminating nul. + * + * @param format a printf-style format string + * @param args arguments for the format string + * @returns length of the given format string and args + */ +int +_dbus_printf_string_upper_bound (const char *format, + va_list args) +{ + char c; + return vsnprintf (&c, 1, format, args); +} + +/** + * Gets the temporary files directory by inspecting the environment variables + * TMPDIR, TMP, and TEMP in that order. If none of those are set "/tmp" is returned + * + * @returns location of temp directory + */ +const char* +_dbus_get_tmpdir(void) +{ + static const char* tmpdir = NULL; + + if (tmpdir == NULL) + { + /* TMPDIR is what glibc uses, then + * glibc falls back to the P_tmpdir macro which + * just expands to "/tmp" + */ + if (tmpdir == NULL) + tmpdir = getenv("TMPDIR"); + + /* These two env variables are probably + * broken, but maybe some OS uses them? + */ + if (tmpdir == NULL) + tmpdir = getenv("TMP"); + if (tmpdir == NULL) + tmpdir = getenv("TEMP"); + + /* And this is the sane fallback. */ + if (tmpdir == NULL) + tmpdir = "/tmp"; + } + + _dbus_assert(tmpdir != NULL); + + return tmpdir; +} + +/** @} end of sysdeps */ + +/* tests in dbus-sysdeps-util.c */ |