70aacd8c0d2e9afc3739808de965d3653b31f0bc
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
);