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 */
32 static struct crypt_data *crypt_data_array;
33 static unsigned cda_size = 0;
35 void enable_crypt(int fd, crypt_function *recv, crypt_function *send,
38 if (fd + 1 > cda_size) {
39 crypt_data_array = para_realloc(crypt_data_array,
40 (fd + 1) * sizeof(struct crypt_data));
41 memset(crypt_data_array + cda_size * sizeof(struct crypt_data), 0,
42 (fd + 1 - cda_size) * sizeof(struct crypt_data));
45 crypt_data_array[fd].recv = recv;
46 crypt_data_array[fd].send = send;
47 crypt_data_array[fd].private_data = private_data;
48 PARA_INFO_LOG("rc4 encryption activated for fd %d\n", fd);
51 void disable_crypt(int fd)
53 if (cda_size < fd + 1)
55 crypt_data_array[fd].recv = NULL;
56 crypt_data_array[fd].send = NULL;
57 crypt_data_array[fd].private_data = NULL;
62 * initialize a struct sockaddr_in
63 * @param addr A pointer to the struct to be initialized
64 * @param port The port number to use
65 * @param he The address to use
67 * If \a he is null (server mode), \a addr->sin_addr is initialized with \p INADDR_ANY.
68 * Otherwise, the address given by \a he is copied to addr.
70 void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he)
73 addr->sin_family = AF_INET;
74 /* short, network byte order */
75 addr->sin_port = htons(port);
77 addr->sin_addr = *((struct in_addr *)he->h_addr);
79 addr->sin_addr.s_addr = INADDR_ANY;
80 /* zero the rest of the struct */
81 memset(&addr->sin_zero, '\0', 8);
85 * send out a buffer, resend on short writes
86 * @param fd the file descriptor
87 * @param buf The buffer to be sent
88 * @len The length of \a buf
90 * Due to circumstances beyond your control, the kernel might not send all the
91 * data out in one chunk, and now, my friend, it's up to us to get the data out
92 * there (Beej's Guide to Network Programming).
94 static int sendall(int fd, const char *buf, size_t *len)
96 int total = 0; /* how many bytes we've sent */
97 int bytesleft = *len; /* how many we have left to send */
100 while (total < *len) {
101 n = send(fd, buf + total, bytesleft, 0);
107 PARA_DEBUG_LOG("short write (%zd byte(s) left)",
110 *len = total; /* return number actually sent here */
111 return n == -1? -E_SEND : 1; /* return 1 on success */
115 * encrypt and send buffer
116 * @param fd: the file descriptor
117 * @param buf the buffer to be encrypted and sent
118 * @param len the length of \a buf
120 * Check if encrytion is available. If yes, encrypt the given buffer. Send out
121 * the buffer, encrypted or not, and try to resend the remaing part in case of
124 * @return Positive on success, \p -E_SEND on errors.
126 int send_bin_buffer(int fd, const char *buf, size_t len)
129 crypt_function *cf = NULL;
132 PARA_CRIT_LOG("%s", "len == 0\n");
133 if (fd + 1 <= cda_size)
134 cf = crypt_data_array[fd].send;
136 void *private = crypt_data_array[fd].private_data;
137 unsigned char *outbuf = para_malloc(len);
138 (*cf)(len, (unsigned char *)buf, outbuf, private);
139 ret = sendall(fd, (char *)outbuf, &len);
142 ret = sendall(fd, buf, &len);
147 * encrypt and send null terminated buffer.
148 * @param fd the file descriptor
149 * @param buf the null-terminated buffer to be send
151 * This is equivalent to send_bin_buffer(fd, buf, strlen(buf)).
153 * @return Positive on success, \p -E_SEND on errors.
155 int send_buffer(int fd, const char *buf)
157 return send_bin_buffer(fd, buf, strlen(buf));
162 * send and encrypt a buffer given by a format string
163 * @param fd the file descriptor
164 * @param fmt a format string
166 * @return Positive on success, \p -E_SEND on errors.
168 __printf_2_3 int send_va_buffer(int fd, const char *fmt, ...)
173 PARA_VSPRINTF(fmt, msg);
174 ret = send_buffer(fd, msg);
180 * receive and decrypt.
182 * @param fd the file descriptor
183 * @param buf the buffer to write the decrypted data to
184 * @param size the size of @param buf
186 * Receive at most \a size bytes from filedescriptor fd. If encrytion is
187 * available, decrypt the received buffer.
189 * @return the number of bytes received on success. On receive errors, -E_RECV
190 * is returned. On crypt errors, the corresponding crypt error number is
194 __must_check int recv_bin_buffer(int fd, char *buf, ssize_t size)
197 crypt_function *cf = NULL;
199 if (fd + 1 <= cda_size)
200 cf = crypt_data_array[fd].recv;
202 unsigned char *tmp = para_malloc(size);
203 void *private = crypt_data_array[fd].private_data;
204 n = recv(fd, tmp, size, 0);
206 (*cf)(n, tmp, (unsigned char *)buf, private);
209 n = recv(fd, buf, size, 0);
216 * receive, decrypt and write terminating NULL byte
218 * @param fd the file descriptor
219 * @param buf the buffer to write the decrypted data to
220 * @param size the size of \a buf
222 * Read and decrypt at most size - 1 bytes from file descriptor \a fd and write
223 * a NULL byte at the end of the received data.
226 int recv_buffer(int fd, char *buf, ssize_t size)
230 n = recv_bin_buffer(fd, buf, size - 1);
239 * wrapper around gethostbyname
241 * \param host hostname or IPv4 address
242 * \param ret the hostent structure is returned here
244 * \return positive on success, negative on errors. On success, \a ret
245 * contains the return value of the underlying gethostbyname() call.
247 * \sa gethostbyname(2)
249 int get_host_info(char *host, struct hostent **ret)
251 PARA_INFO_LOG("getting host info of %s\n", host);
252 /* FIXME: gethostbyname() is obsolete */
253 *ret = gethostbyname(host);
254 return *ret? 1 : -E_HOST_INFO;
258 * a wrapper around socket(2)
260 * Create an IPv4 socket for sequenced, reliable, two-way, connection-based
263 * @return The socket fd on success, -E_SOCKET on errors.
270 if ((socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
276 * a wrapper around connect(2)
278 * @param fd the file descriptor
279 * @param their_addr the address to connect
281 * @return \p -E_CONNECT on errors, 1 on success
284 int para_connect(int fd, struct sockaddr_in *their_addr)
288 if ((ret = connect(fd, (struct sockaddr *)their_addr,
289 sizeof(struct sockaddr))) == -1)
295 * paraslash's wrapper around the accept system call
297 * @param fd the listening socket
298 * @param addr structure which is filled in with the address of the peer socket
299 * @param size should contain the size of the structure pointed to by \a addr
303 int para_accept(int fd, void *addr, socklen_t size)
307 new_fd = accept(fd, (struct sockaddr *) addr, &size);
308 return new_fd == -1? -E_ACCEPT : new_fd;
311 static int setserversockopts(int socket_fd)
315 if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes,
317 return -E_SETSOCKOPT;
322 * prepare a structure for \p AF_UNIX socket addresses
324 * \param u pointer to the struct to be prepared
325 * \param name the socket pathname
327 * This just copies \a name to the sun_path component of \a u.
329 * \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer
330 * than \p UNIX_PATH_MAX.
332 int init_unix_addr(struct sockaddr_un *u, const char *name)
334 if (strlen(name) >= UNIX_PATH_MAX)
335 return -E_NAME_TOO_LONG;
336 memset(u->sun_path, 0, UNIX_PATH_MAX);
337 u->sun_family = PF_UNIX;
338 strcpy(u->sun_path, name);
343 * prepare, create, and bind and socket for local communication
345 * \param name the socket pathname
346 * \param unix_addr pointer to the \p AF_UNIX socket structure
347 * \param mode the desired mode of the socket
349 * This functions creates a local socket for sequenced, reliable,
350 * two-way, connection-based byte streams.
355 int create_pf_socket(const char *name, struct sockaddr_un *unix_addr, int mode)
359 fd = socket(PF_UNIX, SOCK_STREAM, 0);
363 ret = init_unix_addr(unix_addr, name);
366 if (bind(fd, (struct sockaddr *) unix_addr, UNIX_PATH_MAX) < 0)
368 if (chmod(name, mode) < 0)
377 ssize_t send_cred_buffer(int sock, char *buf)
379 return send_buffer(sock, buf);
381 int recv_cred_buffer(int fd, char *buf, size_t size)
383 return recv_buffer(fd, buf, size) > 0? 1 : -E_RECVMSG;
385 #else /* HAVE_UCRED */
387 * send NULL terminated buffer and Unix credentials of the current process
389 * \param sock the socket file descriptor
390 * \param buf the buffer to be sent
392 * \return On success, this call returns the number of characters sent. On
393 * error, \p -E_SENDMSG ist returned.
394 * \sa okir's Black Hats Manual
397 ssize_t send_cred_buffer(int sock, char *buf)
399 char control[sizeof(struct cmsghdr) + 10];
401 struct cmsghdr *cmsg;
402 static struct iovec iov;
408 iov.iov_len = strlen(buf);
412 /* compose the message */
413 memset(&msg, 0, sizeof(msg));
416 msg.msg_control = control;
417 msg.msg_controllen = sizeof(control);
418 /* attach the ucred struct */
419 cmsg = CMSG_FIRSTHDR(&msg);
420 cmsg->cmsg_level = SOL_SOCKET;
421 cmsg->cmsg_type = SCM_CREDENTIALS;
422 cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
423 *(struct ucred *)CMSG_DATA(cmsg) = c;
424 msg.msg_controllen = cmsg->cmsg_len;
425 ret = sendmsg(sock, &msg, 0);
431 static void dispose_fds(int *fds, int num)
435 for (i = 0; i < num; i++)
440 * receive a buffer and the Unix credentials of the sending process
442 * \param fd the socket file descriptor
443 * \param buf the buffer to store the message
444 * \param size the size of \a buffer
446 * \return negative on errors, the user id on success.
448 * \sa okir's Black Hats Manual
451 int recv_cred_buffer(int fd, char *buf, size_t size)
455 struct cmsghdr *cmsg;
461 setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &yes, sizeof(int));
462 memset(&msg, 0, sizeof(msg));
463 memset(buf, 0, size);
468 msg.msg_control = control;
469 msg.msg_controllen = sizeof(control);
470 if (recvmsg(fd, &msg, 0) < 0)
472 result = -E_SCM_CREDENTIALS;
473 cmsg = CMSG_FIRSTHDR(&msg);
475 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type
476 == SCM_CREDENTIALS) {
477 memcpy(&cred, CMSG_DATA(cmsg), sizeof(struct ucred));
480 if (cmsg->cmsg_level == SOL_SOCKET
481 && cmsg->cmsg_type == SCM_RIGHTS) {
482 dispose_fds((int *) CMSG_DATA(cmsg),
483 (cmsg->cmsg_len - CMSG_LEN(0))
486 cmsg = CMSG_NXTHDR(&msg, cmsg);
490 #endif /* HAVE_UCRED */
492 /** how many pending connections queue will hold */
496 * create a socket, bind it and listen
497 * \param port the tcp port to listen on
499 * \return The file descriptor of the created socket, negative
507 int init_tcp_socket(int port)
509 struct sockaddr_in my_addr;
510 int fd, ret = get_socket();
515 ret = setserversockopts(fd);
518 init_sockaddr(&my_addr, port, NULL);
520 if (bind(fd, (struct sockaddr *)&my_addr,
521 sizeof(struct sockaddr)) == -1) {
522 PARA_CRIT_LOG("bind error: %s\n", strerror(errno));
526 if (listen(fd, BACKLOG) == -1)
528 PARA_INFO_LOG("listening on port %d, fd %d\n", port, fd);
536 * receive a buffer and check for a pattern
538 * \param fd the file descriptor to receive from
539 * \param pattern the expected pattern
540 * \param bufsize the size of the internal buffer
542 * \return Positive if \a pattern was received, negative otherwise.
544 * This function creates a buffer of size \a bufsize and tries
545 * to receive at most \a bufsize bytes from file descriptor \a fd.
546 * If at least \p strlen(\a pattern) bytes were received, the beginning of
547 * the received buffer is compared with \a pattern, ignoring case.
551 int recv_pattern(int fd, const char *pattern, size_t bufsize)
553 size_t len = strlen(pattern);
554 char *buf = para_malloc(bufsize + 1);
555 int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize);
559 if (strncasecmp(buf, pattern, len))
564 PARA_NOTICE_LOG("did not receive pattern '%s'\n", pattern);