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 unsigned cda_size = 0;
34 static struct crypt_data *crypt_data_array;
39 * activate encryption for one file descriptor
41 * \param fd the file descriptor
42 * \param recv_f the function used for decrypting received data
43 * \param send_f 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_f, crypt_function *send_f,
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, 0,
53 (fd + 1 - cda_size) * sizeof(struct crypt_data));
56 crypt_data_array[fd].recv = recv_f;
57 crypt_data_array[fd].send = send_f;
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
82 * \param addr A pointer to the struct to be initialized
83 * \param port The port number to use
84 * \param he The address to use
86 * If \a he is null (server mode), \a addr->sin_addr is initialized with \p
87 * INADDR_ANY. Otherwise, the address given by \a he is copied to addr.
89 void init_sockaddr(struct sockaddr_in *addr, int port, const struct hostent *he)
92 addr->sin_family = AF_INET;
93 /* short, network byte order */
94 addr->sin_port = htons(port);
96 addr->sin_addr = *((struct in_addr *)he->h_addr);
98 addr->sin_addr.s_addr = INADDR_ANY;
99 /* zero the rest of the struct */
100 memset(&addr->sin_zero, '\0', 8);
104 * send out a buffer, resend on short writes
106 * \param fd the file descriptor
107 * \param buf The buffer to be sent
108 * \param len The length of \a buf
110 * Due to circumstances beyond your control, the kernel might not send all the
111 * data out in one chunk, and now, my friend, it's up to us to get the data out
112 * there (Beej's Guide to Network Programming).
114 * \return This function returns 1 on success and \a -E_SEND on errors. The
115 * number of bytes actually sent is stored upon successful return in \a len.
117 static int sendall(int fd, const char *buf, size_t *len)
119 int total = 0; /* how many bytes we've sent */
120 int bytesleft = *len; /* how many we have left to send */
123 while (total < *len) {
124 n = send(fd, buf + total, bytesleft, 0);
130 PARA_DEBUG_LOG("short write (%zd byte(s) left)",
133 *len = total; /* return number actually sent here */
134 return n == -1? -E_SEND : 1; /* return 1 on success */
138 * encrypt and send buffer
140 * \param fd: the file descriptor
141 * \param buf the buffer to be encrypted and sent
142 * \param len the length of \a buf
144 * Check if encrytpion is available. If yes, encrypt the given buffer. Send out
145 * the buffer, encrypted or not, and try to resend the remaing part in case of
148 * \return Positive on success, \p -E_SEND on errors.
150 int send_bin_buffer(int fd, const char *buf, size_t len)
153 crypt_function *cf = NULL;
156 PARA_CRIT_LOG("%s", "len == 0\n");
157 if (fd + 1 <= cda_size)
158 cf = crypt_data_array[fd].send;
160 void *private = crypt_data_array[fd].private_data;
161 unsigned char *outbuf = para_malloc(len);
162 (*cf)(len, (unsigned char *)buf, outbuf, private);
163 ret = sendall(fd, (char *)outbuf, &len);
166 ret = sendall(fd, buf, &len);
171 * encrypt and send null terminated buffer.
173 * \param fd the file descriptor
174 * \param buf the null-terminated buffer to be send
176 * This is equivalent to send_bin_buffer(fd, buf, strlen(buf)).
178 * \return Positive on success, \p -E_SEND on errors.
180 int send_buffer(int fd, const char *buf)
182 return send_bin_buffer(fd, buf, strlen(buf));
187 * send and encrypt a buffer given by a format string
189 * \param fd the file descriptor
190 * \param fmt a format string
192 * \return Positive on success, \p -E_SEND on errors.
194 __printf_2_3 int send_va_buffer(int fd, const char *fmt, ...)
199 PARA_VSPRINTF(fmt, msg);
200 ret = send_buffer(fd, msg);
206 * receive and decrypt.
208 * \param fd the file descriptor
209 * \param buf the buffer to write the decrypted data to
210 * \param size the size of \a buf
212 * Receive at most \a size bytes from filedescriptor fd. If encryption is
213 * available, decrypt the received buffer.
215 * \return the number of bytes received on success. On receive errors, -E_RECV
216 * is returned. On crypt errors, the corresponding crypt error number is
221 __must_check int recv_bin_buffer(int fd, char *buf, ssize_t size)
224 crypt_function *cf = NULL;
226 if (fd + 1 <= cda_size)
227 cf = crypt_data_array[fd].recv;
229 unsigned char *tmp = para_malloc(size);
230 void *private = crypt_data_array[fd].private_data;
231 n = recv(fd, tmp, size, 0);
233 (*cf)(n, tmp, (unsigned char *)buf, private);
236 n = recv(fd, buf, size, 0);
243 * receive, decrypt and write terminating NULL byte
245 * \param fd the file descriptor
246 * \param buf the buffer to write the decrypted data to
247 * \param size the size of \a buf
249 * Read and decrypt at most \a size - 1 bytes from file descriptor \a fd and
250 * write a NULL byte at the end of the received data.
253 int recv_buffer(int fd, char *buf, ssize_t size)
257 n = recv_bin_buffer(fd, buf, size - 1);
266 * wrapper around gethostbyname
268 * \param host hostname or IPv4 address
269 * \param ret the hostent structure is returned here
271 * \return positive on success, negative on errors. On success, \a ret
272 * contains the return value of the underlying gethostbyname() call.
274 * \sa gethostbyname(2)
276 int get_host_info(char *host, struct hostent **ret)
278 PARA_INFO_LOG("getting host info of %s\n", host);
279 /* FIXME: gethostbyname() is obsolete */
280 *ret = gethostbyname(host);
281 return *ret? 1 : -E_HOST_INFO;
285 * a wrapper around socket(2)
287 * Create an IPv4 socket for sequenced, reliable, two-way, connection-based
290 * \return The socket fd on success, -E_SOCKET on errors.
298 if ((socket_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
304 * a wrapper around connect(2)
306 * \param fd the file descriptor
307 * \param their_addr the address to connect
309 * \return \p -E_CONNECT on errors, 1 on success
312 int para_connect(int fd, struct sockaddr_in *their_addr)
316 if ((ret = connect(fd, (struct sockaddr *)their_addr,
317 sizeof(struct sockaddr))) == -1)
323 * paraslash's wrapper around the accept system call
325 * \param fd the listening socket
326 * \param addr structure which is filled in with the address of the peer socket
327 * \param size should contain the size of the structure pointed to by \a addr
331 int para_accept(int fd, void *addr, socklen_t size)
336 new_fd = accept(fd, (struct sockaddr *) addr, &size);
337 while (new_fd < 0 && errno == EINTR);
338 return new_fd < 0? -E_ACCEPT : new_fd;
341 static int setserversockopts(int socket_fd)
345 if (setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &yes,
347 return -E_SETSOCKOPT;
352 * prepare a structure for \p AF_UNIX socket addresses
354 * \param u pointer to the struct to be prepared
355 * \param name the socket pathname
357 * This just copies \a name to the sun_path component of \a u.
359 * \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer
360 * than \p UNIX_PATH_MAX.
362 int init_unix_addr(struct sockaddr_un *u, const char *name)
364 if (strlen(name) >= UNIX_PATH_MAX)
365 return -E_NAME_TOO_LONG;
366 memset(u->sun_path, 0, UNIX_PATH_MAX);
367 u->sun_family = PF_UNIX;
368 strcpy(u->sun_path, name);
373 * prepare, create, and bind and socket for local communication
375 * \param name the socket pathname
376 * \param unix_addr pointer to the \p AF_UNIX socket structure
377 * \param mode the desired mode of the socket
379 * This functions creates a local socket for sequenced, reliable,
380 * two-way, connection-based byte streams.
385 int create_pf_socket(const char *name, struct sockaddr_un *unix_addr, int mode)
389 fd = socket(PF_UNIX, SOCK_STREAM, 0);
393 ret = init_unix_addr(unix_addr, name);
396 if (bind(fd, (struct sockaddr *) unix_addr, UNIX_PATH_MAX) < 0)
398 if (chmod(name, mode) < 0)
404 ssize_t send_cred_buffer(int sock, char *buf)
406 return send_buffer(sock, buf);
408 int recv_cred_buffer(int fd, char *buf, size_t size)
410 return recv_buffer(fd, buf, size) > 0? 1 : -E_RECVMSG;
412 #else /* HAVE_UCRED */
414 * send NULL terminated buffer and Unix credentials of the current process
416 * \param sock the socket file descriptor
417 * \param buf the buffer to be sent
419 * \return On success, this call returns the number of characters sent. On
420 * error, \p -E_SENDMSG ist returned.
421 * \sa okir's Black Hats Manual
424 ssize_t send_cred_buffer(int sock, char *buf)
426 char control[sizeof(struct cmsghdr) + 10];
428 struct cmsghdr *cmsg;
429 static struct iovec iov;
435 iov.iov_len = strlen(buf);
439 /* compose the message */
440 memset(&msg, 0, sizeof(msg));
443 msg.msg_control = control;
444 msg.msg_controllen = sizeof(control);
445 /* attach the ucred struct */
446 cmsg = CMSG_FIRSTHDR(&msg);
447 cmsg->cmsg_level = SOL_SOCKET;
448 cmsg->cmsg_type = SCM_CREDENTIALS;
449 cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
450 *(struct ucred *)CMSG_DATA(cmsg) = c;
451 msg.msg_controllen = cmsg->cmsg_len;
452 ret = sendmsg(sock, &msg, 0);
458 static void dispose_fds(int *fds, int num)
462 for (i = 0; i < num; i++)
467 * receive a buffer and the Unix credentials of the sending process
469 * \param fd the socket file descriptor
470 * \param buf the buffer to store the message
471 * \param size the size of \a buffer
473 * \return negative on errors, the user id on success.
475 * \sa okir's Black Hats Manual
478 int recv_cred_buffer(int fd, char *buf, size_t size)
482 struct cmsghdr *cmsg;
488 setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &yes, sizeof(int));
489 memset(&msg, 0, sizeof(msg));
490 memset(buf, 0, size);
495 msg.msg_control = control;
496 msg.msg_controllen = sizeof(control);
497 if (recvmsg(fd, &msg, 0) < 0)
499 result = -E_SCM_CREDENTIALS;
500 cmsg = CMSG_FIRSTHDR(&msg);
502 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type
503 == SCM_CREDENTIALS) {
504 memcpy(&cred, CMSG_DATA(cmsg), sizeof(struct ucred));
507 if (cmsg->cmsg_level == SOL_SOCKET
508 && cmsg->cmsg_type == SCM_RIGHTS) {
509 dispose_fds((int *) CMSG_DATA(cmsg),
510 (cmsg->cmsg_len - CMSG_LEN(0))
513 cmsg = CMSG_NXTHDR(&msg, cmsg);
517 #endif /* HAVE_UCRED */
519 /** how many pending connections queue will hold */
523 * create a socket, bind it and listen
524 * \param port the tcp port to listen on
526 * \return The file descriptor of the created socket, negative
534 int init_tcp_socket(int port)
536 struct sockaddr_in my_addr;
537 int fd, ret = get_socket();
542 ret = setserversockopts(fd);
545 init_sockaddr(&my_addr, port, NULL);
547 if (bind(fd, (struct sockaddr *)&my_addr,
548 sizeof(struct sockaddr)) == -1) {
549 PARA_CRIT_LOG("bind error: %s\n", strerror(errno));
553 if (listen(fd, BACKLOG) == -1)
555 PARA_INFO_LOG("listening on port %d, fd %d\n", port, fd);
563 * receive a buffer and check for a pattern
565 * \param fd the file descriptor to receive from
566 * \param pattern the expected pattern
567 * \param bufsize the size of the internal buffer
569 * \return Positive if \a pattern was received, negative otherwise.
571 * This function creates a buffer of size \a bufsize and tries
572 * to receive at most \a bufsize bytes from file descriptor \a fd.
573 * If at least \p strlen(\a pattern) bytes were received, the beginning of
574 * the received buffer is compared with \a pattern, ignoring case.
578 int recv_pattern(int fd, const char *pattern, size_t bufsize)
580 size_t len = strlen(pattern);
581 char *buf = para_malloc(bufsize + 1);
582 int ret = -E_RECV_PATTERN, n = recv_buffer(fd, buf, bufsize);
586 if (strncasecmp(buf, pattern, len))
591 PARA_NOTICE_LOG("n = %d, did not receive pattern '%s'\n", n, pattern);
593 PARA_NOTICE_LOG("recvd: %s\n", buf);