2 * Copyright (C) 2005-2007 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 /** holds information about one encrypted connection */
29 /** function used to decrypt received data */
31 /** function used to encrypt data to be sent */
33 /** context-dependent data, passed to \a recv() and \a send() */
36 /** array holding per fd crypt data per */
37 static struct crypt_data
*crypt_data_array
;
38 /** current size of the crypt data array */
39 static unsigned cda_size
= 0;
43 * activate encryption for one file descriptor
45 * \param fd the file descriptor
46 * \param recv_f the function used for decrypting received data
47 * \param send_f the function used for encrypting before sending
48 * \param private_data user data supplied by the caller
50 void enable_crypt(int fd
, crypt_function
*recv_f
, crypt_function
*send_f
,
53 if (fd
+ 1 > cda_size
) {
54 crypt_data_array
= para_realloc(crypt_data_array
,
55 (fd
+ 1) * sizeof(struct crypt_data
));
56 memset(crypt_data_array
+ cda_size
, 0,
57 (fd
+ 1 - cda_size
) * sizeof(struct crypt_data
));
60 crypt_data_array
[fd
].recv
= recv_f
;
61 crypt_data_array
[fd
].send
= send_f
;
62 crypt_data_array
[fd
].private_data
= private_data
;
63 PARA_INFO_LOG("rc4 encryption activated for fd %d\n", fd
);
67 * deactivate encryption for a given fd
69 * \param fd the file descriptor
71 * This must be called if and only if \p fd was activated via enable_crypt().
73 void disable_crypt(int fd
)
75 if (cda_size
< fd
+ 1)
77 crypt_data_array
[fd
].recv
= NULL
;
78 crypt_data_array
[fd
].send
= NULL
;
79 crypt_data_array
[fd
].private_data
= NULL
;
84 * initialize a struct sockaddr_in
86 * \param addr A pointer to the struct to be initialized
87 * \param port The port number to use
88 * \param he The address to use
90 * If \a he is null (server mode), \a addr->sin_addr is initialized with \p
91 * INADDR_ANY. Otherwise, the address given by \a he is copied to addr.
93 void init_sockaddr(struct sockaddr_in
*addr
, int port
, const struct hostent
*he
)
96 addr
->sin_family
= AF_INET
;
97 /* short, network byte order */
98 addr
->sin_port
= htons(port
);
100 addr
->sin_addr
= *((struct in_addr
*)he
->h_addr
);
102 addr
->sin_addr
.s_addr
= INADDR_ANY
;
103 /* zero the rest of the struct */
104 memset(&addr
->sin_zero
, '\0', 8);
108 * send out a buffer, resend on short writes
110 * \param fd the file descriptor
111 * \param buf The buffer to be sent
112 * \param len The length of \a buf
114 * Due to circumstances beyond your control, the kernel might not send all the
115 * data out in one chunk, and now, my friend, it's up to us to get the data out
116 * there (Beej's Guide to Network Programming).
118 * \return This function returns 1 on success and \a -E_SEND on errors. The
119 * number of bytes actually sent is stored upon successful return in \a len.
121 static int sendall(int fd
, const char *buf
, size_t *len
)
123 int total
= 0; /* how many bytes we've sent */
124 int bytesleft
= *len
; /* how many we have left to send */
127 while (total
< *len
) {
128 n
= send(fd
, buf
+ total
, bytesleft
, 0);
134 PARA_DEBUG_LOG("short write (%zd byte(s) left)",
137 *len
= total
; /* return number actually sent here */
138 return n
== -1? -E_SEND
: 1; /* return 1 on success */
142 * encrypt and send buffer
144 * \param fd: the file descriptor
145 * \param buf the buffer to be encrypted and sent
146 * \param len the length of \a buf
148 * Check if encrytpion is available. If yes, encrypt the given buffer. Send out
149 * the buffer, encrypted or not, and try to resend the remaing part in case of
152 * \return Positive on success, \p -E_SEND on errors.
154 int send_bin_buffer(int fd
, const char *buf
, size_t len
)
157 crypt_function
*cf
= NULL
;
160 PARA_CRIT_LOG("%s", "len == 0\n");
161 if (fd
+ 1 <= cda_size
)
162 cf
= crypt_data_array
[fd
].send
;
164 void *private = crypt_data_array
[fd
].private_data
;
165 unsigned char *outbuf
= para_malloc(len
);
166 (*cf
)(len
, (unsigned char *)buf
, outbuf
, private);
167 ret
= sendall(fd
, (char *)outbuf
, &len
);
170 ret
= sendall(fd
, buf
, &len
);
175 * encrypt and send null terminated buffer.
177 * \param fd the file descriptor
178 * \param buf the null-terminated buffer to be send
180 * This is equivalent to send_bin_buffer(fd, buf, strlen(buf)).
182 * \return Positive on success, \p -E_SEND on errors.
184 int send_buffer(int fd
, const char *buf
)
186 return send_bin_buffer(fd
, buf
, strlen(buf
));
191 * send and encrypt a buffer given by a format string
193 * \param fd the file descriptor
194 * \param fmt a format string
196 * \return Positive on success, \p -E_SEND on errors.
198 __printf_2_3
int send_va_buffer(int fd
, const char *fmt
, ...)
203 PARA_VSPRINTF(fmt
, msg
);
204 ret
= send_buffer(fd
, msg
);
210 * receive and decrypt.
212 * \param fd the file descriptor
213 * \param buf the buffer to write the decrypted data to
214 * \param size the size of \a buf
216 * Receive at most \a size bytes from filedescriptor fd. If encryption is
217 * available, decrypt the received buffer.
219 * \return The number of bytes received on success. On receive errors, -E_RECV
220 * is returned. On crypt errors, the corresponding crypt error number is
225 __must_check
int recv_bin_buffer(int fd
, char *buf
, ssize_t size
)
228 crypt_function
*cf
= NULL
;
230 if (fd
+ 1 <= cda_size
)
231 cf
= crypt_data_array
[fd
].recv
;
233 unsigned char *tmp
= para_malloc(size
);
234 void *private = crypt_data_array
[fd
].private_data
;
235 n
= recv(fd
, tmp
, size
, 0);
237 (*cf
)(n
, tmp
, (unsigned char *)buf
, private);
240 n
= recv(fd
, buf
, size
, 0);
247 * receive, decrypt and write terminating NULL byte
249 * \param fd the file descriptor
250 * \param buf the buffer to write the decrypted data to
251 * \param size the size of \a buf
253 * Read and decrypt at most \a size - 1 bytes from file descriptor \a fd and
254 * write a NULL byte at the end of the received data.
256 * \return: The return value of the underlying call to \a recv_bin_buffer().
258 * \sa recv_bin_buffer()
260 int recv_buffer(int fd
, char *buf
, ssize_t size
)
264 n
= recv_bin_buffer(fd
, buf
, size
- 1);
273 * wrapper around gethostbyname
275 * \param host hostname or IPv4 address
276 * \param ret the hostent structure is returned here
278 * \return positive on success, negative on errors. On success, \a ret
279 * contains the return value of the underlying gethostbyname() call.
281 * \sa gethostbyname(2)
283 int get_host_info(char *host
, struct hostent
**ret
)
285 PARA_INFO_LOG("getting host info of %s\n", host
);
286 /* FIXME: gethostbyname() is obsolete */
287 *ret
= gethostbyname(host
);
288 return *ret
? 1 : -E_HOST_INFO
;
292 * a wrapper around socket(2)
294 * Create an IPv4 socket for sequenced, reliable, two-way, connection-based
297 * \return The socket fd on success, -E_SOCKET on errors.
305 if ((socket_fd
= socket(AF_INET
, SOCK_STREAM
, 0)) == -1)
311 * a wrapper around connect(2)
313 * \param fd the file descriptor
314 * \param their_addr the address to connect
316 * \return \p -E_CONNECT on errors, 1 on success
320 int para_connect(int fd
, struct sockaddr_in
*their_addr
)
324 if ((ret
= connect(fd
, (struct sockaddr
*)their_addr
,
325 sizeof(struct sockaddr
))) == -1)
331 * paraslash's wrapper around the accept system call
333 * \param fd the listening socket
334 * \param addr structure which is filled in with the address of the peer socket
335 * \param size should contain the size of the structure pointed to by \a addr
337 * Accept incoming connections on \a addr. Retry if interrupted.
339 * \return The new file descriptor on success, \a -E_ACCEPT on errors.
343 int para_accept(int fd
, void *addr
, socklen_t size
)
348 new_fd
= accept(fd
, (struct sockaddr
*) addr
, &size
);
349 while (new_fd
< 0 && errno
== EINTR
);
350 return new_fd
< 0? -E_ACCEPT
: new_fd
;
353 static int setserversockopts(int socket_fd
)
357 if (setsockopt(socket_fd
, SOL_SOCKET
, SO_REUSEADDR
, &yes
,
359 return -E_SETSOCKOPT
;
364 * prepare a structure for \p AF_UNIX socket addresses
366 * \param u pointer to the struct to be prepared
367 * \param name the socket pathname
369 * This just copies \a name to the sun_path component of \a u.
371 * \return Positive on success, \p -E_NAME_TOO_LONG if \a name is longer
372 * than \p UNIX_PATH_MAX.
374 int init_unix_addr(struct sockaddr_un
*u
, const char *name
)
376 if (strlen(name
) >= UNIX_PATH_MAX
)
377 return -E_NAME_TOO_LONG
;
378 memset(u
->sun_path
, 0, UNIX_PATH_MAX
);
379 u
->sun_family
= PF_UNIX
;
380 strcpy(u
->sun_path
, name
);
385 * prepare, create, and bind and socket for local communication
387 * \param name the socket pathname
388 * \param unix_addr pointer to the \p AF_UNIX socket structure
389 * \param mode the desired mode of the socket
391 * This functions creates a local socket for sequenced, reliable,
392 * two-way, connection-based byte streams.
394 * \return The file descriptor, on success, negative on errors.
400 int create_pf_socket(const char *name
, struct sockaddr_un
*unix_addr
, int mode
)
404 fd
= socket(PF_UNIX
, SOCK_STREAM
, 0);
408 ret
= init_unix_addr(unix_addr
, name
);
411 if (bind(fd
, (struct sockaddr
*) unix_addr
, UNIX_PATH_MAX
) < 0)
413 if (chmod(name
, mode
) < 0)
419 ssize_t
send_cred_buffer(int sock
, char *buf
)
421 return send_buffer(sock
, buf
);
423 int recv_cred_buffer(int fd
, char *buf
, size_t size
)
425 return recv_buffer(fd
, buf
, size
) > 0? 1 : -E_RECVMSG
;
427 #else /* HAVE_UCRED */
429 * send NULL terminated buffer and Unix credentials of the current process
431 * \param sock the socket file descriptor
432 * \param buf the buffer to be sent
434 * \return On success, this call returns the number of characters sent. On
435 * error, \p -E_SENDMSG ist returned.
437 * \sa okir's Black Hats Manual
440 ssize_t
send_cred_buffer(int sock
, char *buf
)
442 char control
[sizeof(struct cmsghdr
) + 10];
444 struct cmsghdr
*cmsg
;
445 static struct iovec iov
;
451 iov
.iov_len
= strlen(buf
);
455 /* compose the message */
456 memset(&msg
, 0, sizeof(msg
));
459 msg
.msg_control
= control
;
460 msg
.msg_controllen
= sizeof(control
);
461 /* attach the ucred struct */
462 cmsg
= CMSG_FIRSTHDR(&msg
);
463 cmsg
->cmsg_level
= SOL_SOCKET
;
464 cmsg
->cmsg_type
= SCM_CREDENTIALS
;
465 cmsg
->cmsg_len
= CMSG_LEN(sizeof(struct ucred
));
466 *(struct ucred
*)CMSG_DATA(cmsg
) = c
;
467 msg
.msg_controllen
= cmsg
->cmsg_len
;
468 ret
= sendmsg(sock
, &msg
, 0);
474 static void dispose_fds(int *fds
, int num
)
478 for (i
= 0; i
< num
; i
++)
483 * receive a buffer and the Unix credentials of the sending process
485 * \param fd the socket file descriptor
486 * \param buf the buffer to store the message
487 * \param size the size of \a buffer
489 * \return negative on errors, the user id on success.
491 * \sa okir's Black Hats Manual
494 int recv_cred_buffer(int fd
, char *buf
, size_t size
)
498 struct cmsghdr
*cmsg
;
504 setsockopt(fd
, SOL_SOCKET
, SO_PASSCRED
, &yes
, sizeof(int));
505 memset(&msg
, 0, sizeof(msg
));
506 memset(buf
, 0, size
);
511 msg
.msg_control
= control
;
512 msg
.msg_controllen
= sizeof(control
);
513 if (recvmsg(fd
, &msg
, 0) < 0)
515 result
= -E_SCM_CREDENTIALS
;
516 cmsg
= CMSG_FIRSTHDR(&msg
);
518 if (cmsg
->cmsg_level
== SOL_SOCKET
&& cmsg
->cmsg_type
519 == SCM_CREDENTIALS
) {
520 memcpy(&cred
, CMSG_DATA(cmsg
), sizeof(struct ucred
));
523 if (cmsg
->cmsg_level
== SOL_SOCKET
524 && cmsg
->cmsg_type
== SCM_RIGHTS
) {
525 dispose_fds((int *) CMSG_DATA(cmsg
),
526 (cmsg
->cmsg_len
- CMSG_LEN(0))
529 cmsg
= CMSG_NXTHDR(&msg
, cmsg
);
533 #endif /* HAVE_UCRED */
535 /** how many pending connections queue will hold */
539 * create a socket, bind it and listen
541 * \param port the tcp port to listen on
543 * \return The file descriptor of the created socket, negative
551 int init_tcp_socket(int port
)
553 struct sockaddr_in my_addr
;
554 int fd
, ret
= get_socket();
559 ret
= setserversockopts(fd
);
562 init_sockaddr(&my_addr
, port
, NULL
);
564 if (bind(fd
, (struct sockaddr
*)&my_addr
,
565 sizeof(struct sockaddr
)) == -1) {
566 PARA_CRIT_LOG("bind error: %s\n", strerror(errno
));
570 if (listen(fd
, BACKLOG
) == -1)
572 PARA_INFO_LOG("listening on port %d, fd %d\n", port
, fd
);
580 * receive a buffer and check for a pattern
582 * \param fd the file descriptor to receive from
583 * \param pattern the expected pattern
584 * \param bufsize the size of the internal buffer
586 * \return Positive if \a pattern was received, negative otherwise.
588 * This function creates a buffer of size \a bufsize and tries
589 * to receive at most \a bufsize bytes from file descriptor \a fd.
590 * If at least \p strlen(\a pattern) bytes were received, the beginning of
591 * the received buffer is compared with \a pattern, ignoring case.
596 int recv_pattern(int fd
, const char *pattern
, size_t bufsize
)
598 size_t len
= strlen(pattern
);
599 char *buf
= para_malloc(bufsize
+ 1);
600 int ret
= -E_RECV_PATTERN
, n
= recv_buffer(fd
, buf
, bufsize
);
604 if (strncasecmp(buf
, pattern
, len
))
609 PARA_NOTICE_LOG("n = %d, did not receive pattern '%s'\n", n
, pattern
);
611 PARA_NOTICE_LOG("recvd: %s\n", buf
);