2 * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
19 /** \file net.c networking-related helper functions */
26 static crypt_function **crypt_functions;
27 static unsigned max_crypt_fd;
29 void enable_crypt(int fd, crypt_function *recv, crypt_function *send)
31 if (max_crypt_fd < fd) {
32 crypt_functions = para_realloc(crypt_functions,
33 2 * (fd + 1) * sizeof(crypt_function*));
36 crypt_functions[2 * fd] = recv;
37 crypt_functions[2 * fd + 1] = send;
38 PARA_INFO_LOG("rc4 encryption activated for fd %d\n", fd);
41 void disable_crypt(int fd)
43 crypt_functions[2 * fd] = NULL;
44 crypt_functions[2 * fd + 1] = NULL;
49 * initialize a struct sockaddr_in
50 * @param addr A pointer to the struct to be initialized
51 * @param port The port number to use
52 * @param he The address to use
54 * If \a he is null (server mode), \a addr->sin_addr is initialized with \p INADDR_ANY.
55 * Otherwise, the address given by \a he is copied to addr.
57 void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he)
60 addr->sin_family = AF_INET;
61 /* short, network byte order */
62 addr->sin_port = htons(port);
64 addr->sin_addr = *((struct in_addr *)he->h_addr);
66 addr->sin_addr.s_addr = INADDR_ANY;
67 /* zero the rest of the struct */
68 memset(&addr->sin_zero, '\0', 8);
72 * send out a buffer, resend on short writes
73 * @param fd the file descriptor
74 * @param buf The buffer to be sent
75 * @len The length of \a buf
77 * Due to circumstances beyond your control, the kernel might not send all the
78 * data out in one chunk, and now, my friend, it's up to us to get the data out
79 * there (Beej's Guide to Network Programming).
81 static int sendall(int fd, const char *buf, size_t *len)
83 int total = 0; /* how many bytes we've sent */
84 int bytesleft = *len; /* how many we have left to send */
87 while (total < *len) {
88 n = send(fd, buf + total, bytesleft, 0);
94 PARA_DEBUG_LOG("short write (%zd byte(s) left)",
97 *len = total; /* return number actually sent here */
98 return n == -1? -E_SEND : 1; /* return 1 on success */
102 * encrypt and send buffer
103 * @param fd: the file descriptor
104 * @param buf the buffer to be encrypted and sent
105 * @param len the length of \a buf
107 * Check if encrytion is available. If yes, encrypt the given buffer. Send out
108 * the buffer, encrypted or not, and try to resend the remaing part in case of
111 * @return Positive on success, \p -E_SEND on errors.
113 int send_bin_buffer(int fd, const char *buf, size_t len)
116 crypt_function *cf = NULL;
118 if (fd <= max_crypt_fd)
119 cf = crypt_functions[2 * fd + 1];
122 PARA_CRIT_LOG("%s", "len == 0\n");
124 unsigned char *outbuf = para_malloc(len);
125 (*cf)(len, (unsigned char *)buf, outbuf);
126 ret = sendall(fd, (char *)outbuf, &len);
129 ret = sendall(fd, buf, &len);
134 * encrypt and send null terminated buffer.
135 * @param fd the file descriptor
136 * @param buf the null-terminated buffer to be send
138 * This is equivalent to send_bin_buffer(fd, buf, strlen(buf)).
140 * @return Positive on success, \p -E_SEND on errors.
142 int send_buffer(int fd, const char *buf)
144 return send_bin_buffer(fd, buf, strlen(buf));
149 * send and encrypt a buffer given by a format string
150 * @param fd the file descriptor
151 * @param fmt a format string
153 * @return Positive on success, \p -E_SEND on errors.
155 __printf_2_3 int send_va_buffer(int fd, const char *fmt, ...)
160 PARA_VSPRINTF(fmt, msg);
161 ret = send_buffer(fd, msg);
167 * receive and decrypt.
169 * @param fd the file descriptor
170 * @param buf the buffer to write the decrypted data to
171 * @param size the size of @param buf
173 * Receive at most \a size bytes from filedescriptor fd. If encrytion is
174 * available, decrypt the received buffer.
176 * @return the number of bytes received on success. On receive errors, -E_RECV
177 * is returned. On crypt errors, the corresponding crypt error number is
181 __must_check int recv_bin_buffer(int fd, char *buf, ssize_t size)
184 crypt_function *cf = NULL;
186 if (fd <= max_crypt_fd)
187 cf = crypt_functions[2 * fd];
189 unsigned char *tmp = para_malloc(size);
190 n = recv(fd, tmp, size, 0);
192 (*cf)(n, tmp, (unsigned char *)buf);
195 n = recv(fd, buf, size, 0);
202 * receive, decrypt and write terminating NULL byte
204 * @param fd the file descriptor
205 * @param buf the buffer to write the decrypted data to
206 * @param size the size of \a buf
208 * Read and decrypt at most size - 1 bytes from file descriptor \a fd and write
209 * a NULL byte at the end of the received data.
212 int recv_buffer(int fd, char *buf, ssize_t size)
216 n = recv_bin_buffer(fd, buf, size - 1);
225 * wrapper around gethostbyname
227 * \param host hostname or IPv4 address
228 * \param ret the hostent structure is returned here
230 * \return positive on success, negative on errors. On success, \a ret
231 * contains the return value of the underlying gethostbyname() call.
233 * \sa gethostbyname(2)
235 int get_host_info(char *host, struct hostent **ret)
237 PARA_INFO_LOG("getting host info of %s\n", host);
238 /* FIXME: gethostbyname() is obsolete */
239 *ret = gethostbyname(host);
240 return *ret? 1 : -E_HOST_INFO;
244 * a wrapper around socket(2)
246 * Create an IPv4 socket for sequenced, reliable, two-way, connection-based
249 * @return The socket fd on success, -E_SOCKET on errors.
256 if ((socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
262 * a wrapper around connect(2)
264 * @param fd the file descriptor
265 * @param their_addr the address to connect
267 * @return \p -E_CONNECT on errors, 1 on success
270 int para_connect(int fd, struct sockaddr_in *their_addr)
274 if ((ret = connect(fd, (struct sockaddr *)their_addr,
275 sizeof(struct sockaddr))) == -1)
281 * paraslash's wrapper around the accept system call
283 * @param fd the listening socket
284 * @param addr structure which is filled in with the address of the peer socket
285 * @param size should contain the size of the structure pointed to by \a addr
289 int para_accept(int fd, void *addr, socklen_t size)
293 new_fd = accept(fd, (struct sockaddr *) addr, &size);
294 return new_fd == -1? -E_ACCEPT : new_fd;
297 static int setserversockopts(int socket_fd)
301 if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes,
303 return -E_SETSOCKOPT;
307 static int do_bind(int socket_fd, struct sockaddr_in *my_addr)
309 if (bind(socket_fd, (struct sockaddr *)my_addr,
310 sizeof(struct sockaddr)) == -1)
316 * prepare a structure for \p AF_UNIX socket addresses
318 * \param u pointer to the struct to be prepared
319 * \param name the socket pathname
321 * This just copies \a name to the sun_path component of \a u.
323 * \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer
324 * than \p UNIX_PATH_MAX.
326 int init_unix_addr(struct sockaddr_un *u, const char *name)
328 if (strlen(name) >= UNIX_PATH_MAX)
329 return -E_NAME_TOO_LONG;
330 memset(u->sun_path, 0, UNIX_PATH_MAX);
331 u->sun_family = PF_UNIX;
332 strcpy(u->sun_path, name);
337 * prepare, create, and bind and socket for local communication
339 * \param name the socket pathname
340 * \param unix_addr pointer to the \p AF_UNIX socket structure
341 * \param mode the desired mode of the socket
343 * This functions creates a local socket for sequenced, reliable,
344 * two-way, connection-based byte streams.
349 int create_pf_socket(const char *name, struct sockaddr_un *unix_addr, int mode)
353 fd = socket(PF_UNIX, SOCK_STREAM, 0);
357 ret = init_unix_addr(unix_addr, name);
360 if (bind(fd, (struct sockaddr *) unix_addr, UNIX_PATH_MAX) < 0)
362 if (chmod(name, mode) < 0)
371 ssize_t send_cred_buffer(int sock, char *buf)
373 return send_buffer(sock, buf);
375 int recv_cred_buffer(int fd, char *buf, size_t size)
377 return recv_buffer(fd, buf, size) > 0? 1 : -E_RECVMSG;
379 #else /* HAVE_UCRED */
381 * send NULL terminated buffer and Unix credentials of the current process
383 * \param sock the socket file descriptor
384 * \param buf the buffer to be sent
386 * \return On success, this call returns the number of characters sent. On
387 * error, \p -E_SENDMSG ist returned.
388 * \sa okir's Black Hats Manual
391 ssize_t send_cred_buffer(int sock, char *buf)
393 char control[sizeof(struct cmsghdr) + 10];
395 struct cmsghdr *cmsg;
396 static struct iovec iov;
402 iov.iov_len = strlen(buf);
406 /* compose the message */
407 memset(&msg, 0, sizeof(msg));
410 msg.msg_control = control;
411 msg.msg_controllen = sizeof(control);
412 /* attach the ucred struct */
413 cmsg = CMSG_FIRSTHDR(&msg);
414 cmsg->cmsg_level = SOL_SOCKET;
415 cmsg->cmsg_type = SCM_CREDENTIALS;
416 cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
417 *(struct ucred *)CMSG_DATA(cmsg) = c;
418 msg.msg_controllen = cmsg->cmsg_len;
419 ret = sendmsg(sock, &msg, 0);
425 static void dispose_fds(int *fds, int num)
429 for (i = 0; i < num; i++)
434 * receive a buffer and the Unix credentials of the sending process
436 * \param fd the socket file descriptor
437 * \param buf the buffer to store the message
438 * \param size the size of \a buffer
440 * \return negative on errors, the user id on success.
442 * \sa okir's Black Hats Manual
445 int recv_cred_buffer(int fd, char *buf, size_t size)
449 struct cmsghdr *cmsg;
455 setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &yes, sizeof(int));
456 memset(&msg, 0, sizeof(msg));
457 memset(buf, 0, size);
462 msg.msg_control = control;
463 msg.msg_controllen = sizeof(control);
464 if (recvmsg(fd, &msg, 0) < 0)
466 result = -E_SCM_CREDENTIALS;
467 cmsg = CMSG_FIRSTHDR(&msg);
469 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type
470 == SCM_CREDENTIALS) {
471 memcpy(&cred, CMSG_DATA(cmsg), sizeof(struct ucred));
474 if (cmsg->cmsg_level == SOL_SOCKET
475 && cmsg->cmsg_type == SCM_RIGHTS) {
476 dispose_fds((int *) CMSG_DATA(cmsg),
477 (cmsg->cmsg_len - CMSG_LEN(0))
480 cmsg = CMSG_NXTHDR(&msg, cmsg);
484 #endif /* HAVE_UCRED */
486 /** how many pending connections queue will hold */
490 * create a socket, bind it and listen
491 * \param port the tcp port to listen on
493 * \return The file descriptor of the created socket, negative
501 int init_tcp_socket(int port)
504 struct sockaddr_in my_addr;
506 if ((sockfd = get_socket()) < 0)
508 ret = setserversockopts(sockfd);
511 init_sockaddr(&my_addr, port, NULL);
512 ret = do_bind(sockfd, &my_addr);
515 if (listen(sockfd, BACKLOG) == -1)
517 PARA_INFO_LOG("listening on port %d, fd %d\n", port, sockfd);
522 * receive a buffer and check for a pattern
524 * \param fd the file descriptor to receive from
525 * \param pattern the expected pattern
526 * \param bufsize the size of the internal buffer
528 * \return Positive if \a pattern was received, negative otherwise.
530 * This function creates a buffer of size \a bufsize and tries
531 * to receive at most \a bufsize bytes from file descriptor \a fd.
532 * If at least \p strlen(\a pattern) bytes were received, the beginning of
533 * the received buffer is compared with \a pattern, ignoring case.
537 int recv_pattern(int fd, const char *pattern, size_t bufsize)
539 size_t len = strlen(pattern);
540 char *buf = para_malloc(bufsize + 1);
541 int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize);
545 if (strncasecmp(buf, pattern, len))
550 PARA_NOTICE_LOG("did not receive pattern '%s'\n", pattern);