b05f74da69b62d3fd3a25a7ac58633f1628c1249
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
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("n = %d, did not receive pattern '%s'\n", n
, pattern
);
584 PARA_NOTICE_LOG("recvd: %s\n", buf
);