2 * socket.c -- socket library functions
4 * Copyright 1998 by Eric S. Raymond.
5 * For license terms, see the file COPYING in this directory.
14 #endif /* HAVE_MEMORY_H */
15 #include <sys/types.h>
16 #include <sys/socket.h>
17 #include <netinet/in.h>
18 #include <arpa/inet.h>
20 #if defined(STDC_HEADERS)
23 #if defined(HAVE_UNISTD_H)
26 #if defined(HAVE_STDARG_H)
32 #include "fetchmail.h"
35 /* We need to define h_errno only if it is not already */
38 #ifdef HAVE_RES_SEARCH
39 /* some versions of FreeBSD should declare this but don't */
42 /* pretend we have h_errno to avoid some #ifdef's later */
46 #endif /* ndef h_errno */
49 #include <net/security.h>
50 #endif /* NET_SECURITY */
52 #ifdef HAVE_SOCKETPAIR
53 static int handle_plugin(const char *host,
54 const char *service, const char *plugin)
55 /* get a socket mediated through a given external command */
58 if (socketpair(AF_UNIX,SOCK_STREAM,0,fds))
60 report(stderr, _("fetchmail: socketpair failed\n"));
66 report(stderr, _("fetchmail: fork failed\n"));
70 /* fds[1] is the parent's end; close it for proper EOF
73 if ( (dup2(fds[0],0) == -1) || (dup2(fds[0],1) == -1) ) {
74 report(stderr, _("dup2 failed\n"));
77 /* fds[0] is now connected to 0 and 1; close it */
79 if (outlevel >= O_VERBOSE)
80 report(stderr, _("running %s %s %s\n"), plugin, host, service);
81 execlp(plugin,plugin,host,service,0);
82 report(stderr, _("execl(%s) failed\n"), plugin);
89 /* fds[0] is the child's end; close it for proper EOF detection */
93 #endif /* HAVE_SOCKETPAIR */
98 int SockCheckOpen(int fd)
99 /* poll given socket; is it selectable? */
107 FD_ZERO(&r); FD_ZERO(&w); FD_ZERO(&e);
110 tv.tv_sec = 0; tv.tv_usec = 0;
111 rt = select(fd+1, &r, &w, &e, &tv);
112 if (rt == -1 && (errno != EAGAIN && errno != EINTR))
118 #endif /* __UNUSED__ */
121 int SockOpen(const char *host, const char *service, const char *options,
124 struct addrinfo *ai, req;
127 void *request = NULL;
129 #endif /* NET_SECURITY */
132 #ifdef HAVE_SOCKETPAIR
134 return handle_plugin(host,service,plugin);
135 #endif /* HAVE_SOCKETPAIR */
136 memset(&req, 0, sizeof(struct addrinfo));
137 req.ai_socktype = SOCK_STREAM;
139 if (getaddrinfo(host, service, &req, &ai)) {
140 report(stderr, _("fetchmail: getaddrinfo(%s.%s)\n"), host,service);
148 if (net_security_strtorequest((char *)options, &request, &requestlen))
151 i = inner_connect(ai, request, requestlen, NULL, NULL, "fetchmail", NULL);
156 #else /* NET_SECURITY */
157 i = inner_connect(ai, NULL, 0, NULL, NULL, "fetchmail", NULL);
158 #endif /* NET_SECURITY */
164 #else /* INET6_ENABLE */
165 #ifndef HAVE_INET_ATON
167 #ifdef INADDR_BROADCAST
168 #define INADDR_NONE INADDR_BROADCAST
170 #define INADDR_NONE -1
173 #endif /* HAVE_INET_ATON */
175 int SockOpen(const char *host, int clientPort, const char *options,
178 int sock = -1; /* pacify -Wall */
179 #ifndef HAVE_INET_ATON
180 unsigned long inaddr;
181 #endif /* HAVE_INET_ATON */
182 struct sockaddr_in ad, **pptr;
185 #ifdef HAVE_SOCKETPAIR
188 sprintf(buf,"%d",clientPort);
189 return handle_plugin(host,buf,plugin);
191 #endif /* HAVE_SOCKETPAIR */
193 memset(&ad, 0, sizeof(ad));
194 ad.sin_family = AF_INET;
196 /* we'll accept a quad address */
197 #ifndef HAVE_INET_ATON
198 inaddr = inet_addr(host);
199 if (inaddr != INADDR_NONE)
201 memcpy(&ad.sin_addr, &inaddr, sizeof(inaddr));
203 if (inet_aton(host, &ad.sin_addr))
205 #endif /* HAVE_INET_ATON */
206 ad.sin_port = htons(clientPort);
208 sock = socket(AF_INET, SOCK_STREAM, 0);
214 if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) < 0)
222 #ifndef HAVE_INET_ATON
226 #endif /* HAVE_INET_ATON */
228 hp = gethostbyname(host);
236 * Add a check to make sure the address has a valid IPv4 or IPv6
237 * length. This prevents buffer spamming by a broken DNS.
239 if(hp->h_length != 4 && hp->h_length != 8)
243 _("fetchmail: illegal address length received for host %s\n"),host);
247 * Try all addresses of a possibly multihomed host until we get
248 * a successful connect or until we run out of addresses.
250 pptr = (struct sockaddr_in **)hp->h_addr_list;
251 for(; *pptr != NULL; pptr++)
253 sock = socket(AF_INET, SOCK_STREAM, 0);
259 ad.sin_port = htons(clientPort);
260 memcpy(&ad.sin_addr, *pptr, sizeof(struct in_addr));
261 if (connect(sock, (struct sockaddr *) &ad, sizeof(ad)) == 0)
264 memset(&ad, 0, sizeof(ad));
265 ad.sin_family = AF_INET;
278 #endif /* INET6_ENABLE */
281 #if defined(HAVE_STDARG_H)
282 int SockPrintf(int sock, const char* format, ...)
285 int SockPrintf(sock,format,va_alist)
294 #if defined(HAVE_STDARG_H)
295 va_start(ap, format) ;
299 #ifdef HAVE_VSNPRINTF
300 vsnprintf(buf, sizeof(buf), format, ap);
302 vsprintf(buf, format, ap);
305 return SockWrite(sock, buf, strlen(buf));
315 static SSL_CTX *_ctx = NULL;
316 static SSL *_ssl_context[FD_SETSIZE];
318 SSL *SSLGetContext( int );
319 #endif /* SSL_ENABLE */
321 int SockWrite(int sock, char *buf, int len)
331 if( NULL != ( ssl = SSLGetContext( sock ) ) )
332 n = SSL_write(ssl, buf, len);
334 n = write(sock, buf, len);
336 n = write(sock, buf, len);
347 int SockRead(int sock, char *buf, int len)
349 char *newline, *bp = buf;
359 * The reason for these gymnastics is that we want two things:
360 * (1) to read \n-terminated lines,
361 * (2) to return the true length of data read, even if the
362 * data coming in has embedded NULS.
365 if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
367 /* OK... SSL_peek works a little different from MSG_PEEK
368 Problem is that SSL_peek can return 0 if there
369 is no data currently available. If, on the other
370 hand, we loose the socket, we also get a zero, but
371 the SSL_read then SEGFAULTS! To deal with this,
372 we'll check the error code any time we get a return
373 of zero from SSL_peek. If we have an error, we bail.
374 If we don't, we read one character in SSL_read and
375 loop. This should continue to work even if they
376 later change the behavior of SSL_peek
377 to "fix" this problem... :-( */
378 if ((n = SSL_peek(ssl, bp, len)) < 0) {
382 /* SSL_peek says no data... Does he mean no data
383 or did the connection blow up? If we got an error
385 if( 0 != ( n = ERR_get_error() ) ) {
388 /* We didn't get an error so read at least one
389 character at this point and loop */
391 /* Make sure newline start out NULL!
392 * We don't have a string to pass through
393 * the strchr at this point yet */
395 } else if ((newline = memchr(bp, '\n', n)) != NULL)
396 n = newline - bp + 1;
397 if ((n = SSL_read(ssl, bp, n)) == -1) {
400 /* Check for case where our single character turned out to
401 * be a newline... (It wasn't going to get caught by
402 * the strchr above if it came from the hack... ). */
403 if( NULL == newline && 1 == n && '\n' == *bp ) {
404 /* Got our newline - this will break
405 out of the loop now */
409 if ((n = recv(sock, bp, len, MSG_PEEK)) <= 0)
411 if ((newline = memchr(bp, '\n', n)) != NULL)
412 n = newline - bp + 1;
413 if ((n = read(sock, bp, n)) == -1)
417 if ((n = recv(sock, bp, len, MSG_PEEK)) <= 0)
419 if ((newline = memchr(bp, '\n', n)) != NULL)
420 n = newline - bp + 1;
421 if ((n = read(sock, bp, n)) == -1)
432 int SockPeek(int sock)
433 /* peek at the next socket character without actually reading it */
442 if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
443 n = SSL_peek(ssl, &ch, 1);
445 /* This code really needs to implement a "hold back"
446 * to simulate a functioning SSL_peek()... sigh...
447 * Has to be coordinated with the read code above.
448 * Next on the list todo... */
450 /* SSL_peek says no data... Does he mean no data
451 or did the connection blow up? If we got an error
453 if( 0 != ( n = ERR_get_error() ) ) {
457 /* Haven't seen this case actually occur, but...
458 if the problem in SockRead can occur, this should
459 be possible... Just not sure what to do here.
460 This should be a safe "punt" the "peek" but don't
461 "punt" the "session"... */
463 return 0; /* Give him a '\0' character */
466 n = recv(sock, &ch, 1, MSG_PEEK);
469 n = recv(sock, &ch, 1, MSG_PEEK);
479 static char *_ssl_server_cname = NULL;
481 SSL *SSLGetContext( int sock )
483 /* If SSLOpen has never initialized - just return NULL */
487 if( sock < 0 || sock > FD_SETSIZE )
489 return _ssl_context[sock];
493 int SSL_verify_callback( int ok_return, X509_STORE_CTX *ctx )
502 x509_cert = X509_STORE_CTX_get_current_cert(ctx);
503 err = X509_STORE_CTX_get_error(ctx);
504 depth = X509_STORE_CTX_get_error_depth(ctx);
506 X509_NAME_oneline(X509_get_subject_name(x509_cert), buf, 256);
507 X509_NAME_oneline(X509_get_issuer_name(x509_cert), ibuf, 256);
509 /* Just to be sure those buffers are terminated... I think the
510 X509 libraries do, but... */
511 buf[256] = ibuf[256] = '\0';
514 if( ( str_ptr = strstr( ibuf, "/O=" ) ) ) {
516 strcpy( cbuf, str_ptr );
517 if( ( str_ptr = strchr(cbuf, '/' ) ) ) {
520 if (outlevel == O_VERBOSE)
521 report(stdout, "Issuer Organization: %s", cbuf );
523 if (outlevel == O_VERBOSE)
524 report(stdout, "Unknown Organization", cbuf );
526 if( ( str_ptr = strstr( ibuf, "/CN=" ) ) ) {
528 strcpy( cbuf, str_ptr );
529 if( ( str_ptr = strchr(cbuf, '/' ) ) ) {
532 if (outlevel == O_VERBOSE)
533 report(stdout, "Issuer CommonName: %s", cbuf );
535 if (outlevel == O_VERBOSE)
536 report(stdout, "Unknown Issuer CommonName", cbuf );
538 if( ( str_ptr = strstr( buf, "/CN=" ) ) ) {
540 strcpy( cbuf, str_ptr );
541 if( ( str_ptr = strchr(cbuf, '/' ) ) ) {
544 if (outlevel == O_VERBOSE)
545 report(stdout, "Server CommonName: %s", cbuf );
546 /* Should we have some wildcarding here? */
547 if ( NULL != _ssl_server_cname && 0 != strcmp( cbuf, _ssl_server_cname ) ) {
548 report(stdout, "Server CommonName mismatch: %s != %s", cbuf, _ssl_server_cname );
551 if (outlevel == O_VERBOSE)
552 report(stdout, "Unknown Server CommonName", cbuf );
556 switch (ctx->error) {
557 case X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT:
558 X509_NAME_oneline(X509_get_issuer_name(ctx->current_cert), buf, 256);
559 report(stdout, "unknown issuer= %s", buf);
561 case X509_V_ERR_CERT_NOT_YET_VALID:
562 case X509_V_ERR_ERROR_IN_CERT_NOT_BEFORE_FIELD:
563 report(stderr, "Server Certificate not yet valid");
565 case X509_V_ERR_CERT_HAS_EXPIRED:
566 case X509_V_ERR_ERROR_IN_CERT_NOT_AFTER_FIELD:
567 report(stderr, "Server Certificate expired");
570 /* We are not requiring or validating server or issuer id's as yet */
571 /* Always return OK from here */
577 /* performs initial SSL handshake over the connected socket
578 * uses SSL *ssl global variable, which is currently defined
581 int SSLOpen(int sock, char *mycert, char *mykey, char *servercname )
583 SSL_load_error_strings();
584 SSLeay_add_ssl_algorithms();
586 if( sock < 0 || sock > FD_SETSIZE ) {
587 report(stderr, "File descriptor out of range for SSL" );
592 /* Be picky and make sure the memory is cleared */
593 memset( _ssl_context, 0, sizeof( _ssl_context ) );
594 _ctx = SSL_CTX_new(SSLv23_client_method());
596 ERR_print_errors_fp(stderr);
601 _ssl_context[sock] = SSL_new(_ctx);
603 if(_ssl_context[sock] == NULL) {
604 ERR_print_errors_fp(stderr);
608 /* This static is for the verify callback */
609 _ssl_server_cname = servercname;
611 SSL_CTX_set_verify(_ctx, SSL_VERIFY_PEER, SSL_verify_callback);
613 if( mycert || mykey ) {
615 /* Ok... He has a certificate file defined, so lets declare it. If
616 * he does NOT have a separate certificate and private key file then
617 * assume that it's a combined key and certificate file.
623 SSL_use_certificate_file(_ssl_context[sock], mycert, SSL_FILETYPE_PEM);
624 SSL_use_RSAPrivateKey_file(_ssl_context[sock], mykey, SSL_FILETYPE_PEM);
627 SSL_set_fd(_ssl_context[sock], sock);
629 if(SSL_connect(_ssl_context[sock]) == -1) {
630 ERR_print_errors_fp(stderr);
638 int SockClose(int sock)
639 /* close a socket (someday we may do other cleanup here) */
644 if( NULL != ( ssl = SSLGetContext( sock ) ) ) {
645 /* Clean up the SSL stack */
646 SSL_free( _ssl_context[sock] );
647 _ssl_context[sock] = NULL;
655 * Use the chargen service to test input buffering directly.
656 * You may have to uncomment the `chargen' service description in your
657 * inetd.conf (and then SIGHUP inetd) for this to work.
661 int sock = SockOpen("localhost", 19, NULL);
664 while (SockRead(sock, buf, sizeof(buf)-1))
665 SockWrite(1, buf, strlen(buf));
670 /* socket.c ends here */