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 */
27 /** \cond holds information about one encrypted connection */
33 static struct crypt_data *crypt_data_array;
34 static unsigned cda_size = 0;
39 * activate encryption for one file descriptor
41 * \param fd the file descriptor
42 * \param recv the function used for decrypting received data
43 * \param send the function used for encrypting before sending
44 * \param private_data user data supplied by the caller
46 void enable_crypt(int fd, crypt_function *recv, crypt_function *send,
49 if (fd + 1 > cda_size) {
50 crypt_data_array = para_realloc(crypt_data_array,
51 (fd + 1) * sizeof(struct crypt_data));
52 memset(crypt_data_array + cda_size * sizeof(struct crypt_data), 0,
53 (fd + 1 - cda_size) * sizeof(struct crypt_data));
56 crypt_data_array[fd].recv = recv;
57 crypt_data_array[fd].send = send;
58 crypt_data_array[fd].private_data = private_data;
59 PARA_INFO_LOG("rc4 encryption activated for fd %d\n", fd);
63 * deactivate encryption for a given fd
65 * \param fd the file descriptor
67 * This must be called if and only if \p fd was activated via enable_crypt().
69 void disable_crypt(int fd)
71 if (cda_size < fd + 1)
73 crypt_data_array[fd].recv = NULL;
74 crypt_data_array[fd].send = NULL;
75 crypt_data_array[fd].private_data = NULL;
80 * initialize a struct sockaddr_in
81 * @param addr A pointer to the struct to be initialized
82 * @param port The port number to use
83 * @param he The address to use
85 * If \a he is null (server mode), \a addr->sin_addr is initialized with \p INADDR_ANY.
86 * Otherwise, the address given by \a he is copied to addr.
88 void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he)
91 addr->sin_family = AF_INET;
92 /* short, network byte order */
93 addr->sin_port = htons(port);
95 addr->sin_addr = *((struct in_addr *)he->h_addr);
97 addr->sin_addr.s_addr = INADDR_ANY;
98 /* zero the rest of the struct */
99 memset(&addr->sin_zero, '\0', 8);
103 * send out a buffer, resend on short writes
104 * @param fd the file descriptor
105 * @param buf The buffer to be sent
106 * @len The length of \a buf
108 * Due to circumstances beyond your control, the kernel might not send all the
109 * data out in one chunk, and now, my friend, it's up to us to get the data out
110 * there (Beej's Guide to Network Programming).
112 static int sendall(int fd, const char *buf, size_t *len)
114 int total = 0; /* how many bytes we've sent */
115 int bytesleft = *len; /* how many we have left to send */
118 while (total < *len) {
119 n = send(fd, buf + total, bytesleft, 0);
125 PARA_DEBUG_LOG("short write (%zd byte(s) left)",
128 *len = total; /* return number actually sent here */
129 return n == -1? -E_SEND : 1; /* return 1 on success */
133 * encrypt and send buffer
134 * @param fd: the file descriptor
135 * @param buf the buffer to be encrypted and sent
136 * @param len the length of \a buf
138 * Check if encrytion is available. If yes, encrypt the given buffer. Send out
139 * the buffer, encrypted or not, and try to resend the remaing part in case of
142 * @return Positive on success, \p -E_SEND on errors.
144 int send_bin_buffer(int fd, const char *buf, size_t len)
147 crypt_function *cf = NULL;
150 PARA_CRIT_LOG("%s", "len == 0\n");
151 if (fd + 1 <= cda_size)
152 cf = crypt_data_array[fd].send;
154 void *private = crypt_data_array[fd].private_data;
155 unsigned char *outbuf = para_malloc(len);
156 (*cf)(len, (unsigned char *)buf, outbuf, private);
157 ret = sendall(fd, (char *)outbuf, &len);
160 ret = sendall(fd, buf, &len);
165 * encrypt and send null terminated buffer.
166 * @param fd the file descriptor
167 * @param buf the null-terminated buffer to be send
169 * This is equivalent to send_bin_buffer(fd, buf, strlen(buf)).
171 * @return Positive on success, \p -E_SEND on errors.
173 int send_buffer(int fd, const char *buf)
175 return send_bin_buffer(fd, buf, strlen(buf));
180 * send and encrypt a buffer given by a format string
181 * @param fd the file descriptor
182 * @param fmt a format string
184 * @return Positive on success, \p -E_SEND on errors.
186 __printf_2_3 int send_va_buffer(int fd, const char *fmt, ...)
191 PARA_VSPRINTF(fmt, msg);
192 ret = send_buffer(fd, msg);
198 * receive and decrypt.
200 * @param fd the file descriptor
201 * @param buf the buffer to write the decrypted data to
202 * @param size the size of @param buf
204 * Receive at most \a size bytes from filedescriptor fd. If encrytion is
205 * available, decrypt the received buffer.
207 * @return the number of bytes received on success. On receive errors, -E_RECV
208 * is returned. On crypt errors, the corresponding crypt error number is
212 __must_check int recv_bin_buffer(int fd, char *buf, ssize_t size)
215 crypt_function *cf = NULL;
217 if (fd + 1 <= cda_size)
218 cf = crypt_data_array[fd].recv;
220 unsigned char *tmp = para_malloc(size);
221 void *private = crypt_data_array[fd].private_data;
222 n = recv(fd, tmp, size, 0);
224 (*cf)(n, tmp, (unsigned char *)buf, private);
227 n = recv(fd, buf, size, 0);
234 * receive, decrypt and write terminating NULL byte
236 * @param fd the file descriptor
237 * @param buf the buffer to write the decrypted data to
238 * @param size the size of \a buf
240 * Read and decrypt at most size - 1 bytes from file descriptor \a fd and write
241 * a NULL byte at the end of the received data.
244 int recv_buffer(int fd, char *buf, ssize_t size)
248 n = recv_bin_buffer(fd, buf, size - 1);
257 * wrapper around gethostbyname
259 * \param host hostname or IPv4 address
260 * \param ret the hostent structure is returned here
262 * \return positive on success, negative on errors. On success, \a ret
263 * contains the return value of the underlying gethostbyname() call.
265 * \sa gethostbyname(2)
267 int get_host_info(char *host, struct hostent **ret)
269 PARA_INFO_LOG("getting host info of %s\n", host);
270 /* FIXME: gethostbyname() is obsolete */
271 *ret = gethostbyname(host);
272 return *ret? 1 : -E_HOST_INFO;
276 * a wrapper around socket(2)
278 * Create an IPv4 socket for sequenced, reliable, two-way, connection-based
281 * @return The socket fd on success, -E_SOCKET on errors.
288 if ((socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
294 * a wrapper around connect(2)
296 * @param fd the file descriptor
297 * @param their_addr the address to connect
299 * @return \p -E_CONNECT on errors, 1 on success
302 int para_connect(int fd, struct sockaddr_in *their_addr)
306 if ((ret = connect(fd, (struct sockaddr *)their_addr,
307 sizeof(struct sockaddr))) == -1)
313 * paraslash's wrapper around the accept system call
315 * @param fd the listening socket
316 * @param addr structure which is filled in with the address of the peer socket
317 * @param size should contain the size of the structure pointed to by \a addr
321 int para_accept(int fd, void *addr, socklen_t size)
325 new_fd = accept(fd, (struct sockaddr *) addr, &size);
326 return new_fd == -1? -E_ACCEPT : new_fd;
329 static int setserversockopts(int socket_fd)
333 if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes,
335 return -E_SETSOCKOPT;
340 * prepare a structure for \p AF_UNIX socket addresses
342 * \param u pointer to the struct to be prepared
343 * \param name the socket pathname
345 * This just copies \a name to the sun_path component of \a u.
347 * \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer
348 * than \p UNIX_PATH_MAX.
350 int init_unix_addr(struct sockaddr_un *u, const char *name)
352 if (strlen(name) >= UNIX_PATH_MAX)
353 return -E_NAME_TOO_LONG;
354 memset(u->sun_path, 0, UNIX_PATH_MAX);
355 u->sun_family = PF_UNIX;
356 strcpy(u->sun_path, name);
361 * prepare, create, and bind and socket for local communication
363 * \param name the socket pathname
364 * \param unix_addr pointer to the \p AF_UNIX socket structure
365 * \param mode the desired mode of the socket
367 * This functions creates a local socket for sequenced, reliable,
368 * two-way, connection-based byte streams.
373 int create_pf_socket(const char *name, struct sockaddr_un *unix_addr, int mode)
377 fd = socket(PF_UNIX, SOCK_STREAM, 0);
381 ret = init_unix_addr(unix_addr, name);
384 if (bind(fd, (struct sockaddr *) unix_addr, UNIX_PATH_MAX) < 0)
386 if (chmod(name, mode) < 0)
395 ssize_t send_cred_buffer(int sock, char *buf)
397 return send_buffer(sock, buf);
399 int recv_cred_buffer(int fd, char *buf, size_t size)
401 return recv_buffer(fd, buf, size) > 0? 1 : -E_RECVMSG;
403 #else /* HAVE_UCRED */
405 * send NULL terminated buffer and Unix credentials of the current process
407 * \param sock the socket file descriptor
408 * \param buf the buffer to be sent
410 * \return On success, this call returns the number of characters sent. On
411 * error, \p -E_SENDMSG ist returned.
412 * \sa okir's Black Hats Manual
415 ssize_t send_cred_buffer(int sock, char *buf)
417 char control[sizeof(struct cmsghdr) + 10];
419 struct cmsghdr *cmsg;
420 static struct iovec iov;
426 iov.iov_len = strlen(buf);
430 /* compose the message */
431 memset(&msg, 0, sizeof(msg));
434 msg.msg_control = control;
435 msg.msg_controllen = sizeof(control);
436 /* attach the ucred struct */
437 cmsg = CMSG_FIRSTHDR(&msg);
438 cmsg->cmsg_level = SOL_SOCKET;
439 cmsg->cmsg_type = SCM_CREDENTIALS;
440 cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
441 *(struct ucred *)CMSG_DATA(cmsg) = c;
442 msg.msg_controllen = cmsg->cmsg_len;
443 ret = sendmsg(sock, &msg, 0);
449 static void dispose_fds(int *fds, int num)
453 for (i = 0; i < num; i++)
458 * receive a buffer and the Unix credentials of the sending process
460 * \param fd the socket file descriptor
461 * \param buf the buffer to store the message
462 * \param size the size of \a buffer
464 * \return negative on errors, the user id on success.
466 * \sa okir's Black Hats Manual
469 int recv_cred_buffer(int fd, char *buf, size_t size)
473 struct cmsghdr *cmsg;
479 setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &yes, sizeof(int));
480 memset(&msg, 0, sizeof(msg));
481 memset(buf, 0, size);
486 msg.msg_control = control;
487 msg.msg_controllen = sizeof(control);
488 if (recvmsg(fd, &msg, 0) < 0)
490 result = -E_SCM_CREDENTIALS;
491 cmsg = CMSG_FIRSTHDR(&msg);
493 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type
494 == SCM_CREDENTIALS) {
495 memcpy(&cred, CMSG_DATA(cmsg), sizeof(struct ucred));
498 if (cmsg->cmsg_level == SOL_SOCKET
499 && cmsg->cmsg_type == SCM_RIGHTS) {
500 dispose_fds((int *) CMSG_DATA(cmsg),
501 (cmsg->cmsg_len - CMSG_LEN(0))
504 cmsg = CMSG_NXTHDR(&msg, cmsg);
508 #endif /* HAVE_UCRED */
510 /** how many pending connections queue will hold */
514 * create a socket, bind it and listen
515 * \param port the tcp port to listen on
517 * \return The file descriptor of the created socket, negative
525 int init_tcp_socket(int port)
527 struct sockaddr_in my_addr;
528 int fd, ret = get_socket();
533 ret = setserversockopts(fd);
536 init_sockaddr(&my_addr, port, NULL);
538 if (bind(fd, (struct sockaddr *)&my_addr,
539 sizeof(struct sockaddr)) == -1) {
540 PARA_CRIT_LOG("bind error: %s\n", strerror(errno));
544 if (listen(fd, BACKLOG) == -1)
546 PARA_INFO_LOG("listening on port %d, fd %d\n", port, fd);
554 * receive a buffer and check for a pattern
556 * \param fd the file descriptor to receive from
557 * \param pattern the expected pattern
558 * \param bufsize the size of the internal buffer
560 * \return Positive if \a pattern was received, negative otherwise.
562 * This function creates a buffer of size \a bufsize and tries
563 * to receive at most \a bufsize bytes from file descriptor \a fd.
564 * If at least \p strlen(\a pattern) bytes were received, the beginning of
565 * the received buffer is compared with \a pattern, ignoring case.
569 int recv_pattern(int fd, const char *pattern, size_t bufsize)
571 size_t len = strlen(pattern);
572 char *buf = para_malloc(bufsize + 1);
573 int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize);
577 if (strncasecmp(buf, pattern, len))
582 PARA_NOTICE_LOG("did not receive pattern '%s'\n", pattern);