1/*
2 * Copyright (c) 2002 - 2003
3 * NetGroup, Politecnico di Torino (Italy)
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the Politecnico di Torino nor the names of its
16 * contributors may be used to endorse or promote products derived from
17 * this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
23 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
25 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
27 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 */
32
33#ifdef HAVE_CONFIG_H
34#include <config.h>
35#endif
36
37/*
38 * \file sockutils.c
39 *
40 * The goal of this file is to provide a common set of primitives for socket
41 * manipulation.
42 *
43 * Although the socket interface defined in the RFC 2553 (and its updates)
44 * is excellent, there are still differences between the behavior of those
45 * routines on UN*X and Windows, and between UN*Xes.
46 *
47 * These calls provide an interface similar to the socket interface, but
48 * that hides the differences between operating systems.  It does not
49 * attempt to significantly improve on the socket interface in other
50 * ways.
51 */
52
53#include "ftmacros.h"
54
55#include <string.h>
56#include <errno.h>	/* for the errno variable */
57#include <stdio.h>	/* for the stderr file */
58#include <stdlib.h>	/* for malloc() and free() */
59#ifdef HAVE_LIMITS_H
60#include <limits.h>
61#else
62#define INT_MAX		2147483647
63#endif
64
65#include "pcap-int.h"
66
67#include "sockutils.h"
68#include "portability.h"
69
70#ifdef _WIN32
71  /*
72   * Winsock initialization.
73   *
74   * Ask for WinSock 2.2.
75   */
76  #define WINSOCK_MAJOR_VERSION 2
77  #define WINSOCK_MINOR_VERSION 2
78
79  static int sockcount = 0;	/*!< Variable that allows calling the WSAStartup() only one time */
80#endif
81
82/* Some minor differences between UNIX and Win32 */
83#ifdef _WIN32
84  #define SHUT_WR SD_SEND	/* The control code for shutdown() is different in Win32 */
85#endif
86
87/* Size of the buffer that has to keep error messages */
88#define SOCK_ERRBUF_SIZE 1024
89
90/* Constants; used in order to keep strings here */
91#define SOCKET_NO_NAME_AVAILABLE "No name available"
92#define SOCKET_NO_PORT_AVAILABLE "No port available"
93#define SOCKET_NAME_NULL_DAD "Null address (possibly DAD Phase)"
94
95/*
96 * On UN*X, send() and recv() return ssize_t.
97 *
98 * On Windows, send() and recv() return an int.
99 *
100 *   Wth MSVC, there *is* no ssize_t.
101 *
102 *   With MinGW, there is an ssize_t type; it is either an int (32 bit)
103 *   or a long long (64 bit).
104 *
105 * So, on Windows, if we don't have ssize_t defined, define it as an
106 * int, so we can use it, on all platforms, as the type of variables
107 * that hold the return values from send() and recv().
108 */
109#if defined(_WIN32) && !defined(_SSIZE_T_DEFINED)
110typedef int ssize_t;
111#endif
112
113/****************************************************
114 *                                                  *
115 * Locally defined functions                        *
116 *                                                  *
117 ****************************************************/
118
119static int sock_ismcastaddr(const struct sockaddr *saddr);
120
121/****************************************************
122 *                                                  *
123 * Function bodies                                  *
124 *                                                  *
125 ****************************************************/
126
127/*
128 * Format an error message given an errno value (UN*X) or a WinSock error
129 * (Windows).
130 */
131void sock_fmterror(const char *caller, int errcode, char *errbuf, int errbuflen)
132{
133#ifdef _WIN32
134	int retval;
135	TCHAR message[SOCK_ERRBUF_SIZE];	/* It will be char (if we're using ascii) or wchar_t (if we're using unicode) */
136
137	if (errbuf == NULL)
138		return;
139
140	retval = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS |
141		FORMAT_MESSAGE_MAX_WIDTH_MASK,
142		NULL, errcode, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
143		message, sizeof(message) / sizeof(TCHAR), NULL);
144
145	if (retval == 0)
146	{
147		if ((caller) && (*caller))
148			pcap_snprintf(errbuf, errbuflen, "%sUnable to get the exact error message", caller);
149		else
150			pcap_snprintf(errbuf, errbuflen, "Unable to get the exact error message");
151	}
152	else
153	{
154		if ((caller) && (*caller))
155			pcap_snprintf(errbuf, errbuflen, "%s%s (code %d)", caller, message, errcode);
156		else
157			pcap_snprintf(errbuf, errbuflen, "%s (code %d)", message, errcode);
158	}
159#else
160	char *message;
161
162	if (errbuf == NULL)
163		return;
164
165	message = strerror(errcode);
166
167	if ((caller) && (*caller))
168		pcap_snprintf(errbuf, errbuflen, "%s%s (code %d)", caller, message, errcode);
169	else
170		pcap_snprintf(errbuf, errbuflen, "%s (code %d)", message, errcode);
171#endif
172}
173
174/*
175 * \brief It retrieves the error message after an error occurred in the socket interface.
176 *
177 * This function is defined because of the different way errors are returned in UNIX
178 * and Win32. This function provides a consistent way to retrieve the error message
179 * (after a socket error occurred) on all the platforms.
180 *
181 * \param caller: a pointer to a user-allocated string which contains a message that has
182 * to be printed *before* the true error message. It could be, for example, 'this error
183 * comes from the recv() call at line 31'. It may be NULL.
184 *
185 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
186 * error message. This buffer has to be at least 'errbuflen' in length.
187 * It can be NULL; in this case the error cannot be printed.
188 *
189 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
190 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
191 *
192 * \return No return values. The error message is returned in the 'string' parameter.
193 */
194void sock_geterror(const char *caller, char *errbuf, int errbuflen)
195{
196#ifdef _WIN32
197	if (errbuf == NULL)
198		return;
199	sock_fmterror(caller, GetLastError(), errbuf, errbuflen);
200#else
201	if (errbuf == NULL)
202		return;
203	sock_fmterror(caller, errno, errbuf, errbuflen);
204#endif
205}
206
207/*
208 * \brief It initializes sockets.
209 *
210 * This function is pretty useless on UNIX, since socket initialization is not required.
211 * However it is required on Win32. In UNIX, this function appears to be completely empty.
212 *
213 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
214 * error message. This buffer has to be at least 'errbuflen' in length.
215 * It can be NULL; in this case the error cannot be printed.
216 *
217 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
218 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
219 *
220 * \return '0' if everything is fine, '-1' if some errors occurred. The error message is returned
221 * in the 'errbuf' variable.
222 */
223#ifdef _WIN32
224int sock_init(char *errbuf, int errbuflen)
225{
226	if (sockcount == 0)
227	{
228		WSADATA wsaData;			/* helper variable needed to initialize Winsock */
229
230		if (WSAStartup(MAKEWORD(WINSOCK_MAJOR_VERSION,
231		    WINSOCK_MINOR_VERSION), &wsaData) != 0)
232		{
233			if (errbuf)
234				pcap_snprintf(errbuf, errbuflen, "Failed to initialize Winsock\n");
235
236			WSACleanup();
237
238			return -1;
239		}
240	}
241
242	sockcount++;
243#else
244int sock_init(char *errbuf _U_, int errbuflen _U_)
245{
246#endif
247	return 0;
248}
249
250/*
251 * \brief It deallocates sockets.
252 *
253 * This function is pretty useless on UNIX, since socket deallocation is not required.
254 * However it is required on Win32. In UNIX, this function appears to be completely empty.
255 *
256 * \return No error values.
257 */
258void sock_cleanup(void)
259{
260#ifdef _WIN32
261	sockcount--;
262
263	if (sockcount == 0)
264		WSACleanup();
265#endif
266}
267
268/*
269 * \brief It checks if the sockaddr variable contains a multicast address.
270 *
271 * \return '0' if the address is multicast, '-1' if it is not.
272 */
273static int sock_ismcastaddr(const struct sockaddr *saddr)
274{
275	if (saddr->sa_family == PF_INET)
276	{
277		struct sockaddr_in *saddr4 = (struct sockaddr_in *) saddr;
278		if (IN_MULTICAST(ntohl(saddr4->sin_addr.s_addr))) return 0;
279		else return -1;
280	}
281	else
282	{
283		struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *) saddr;
284		if (IN6_IS_ADDR_MULTICAST(&saddr6->sin6_addr)) return 0;
285		else return -1;
286	}
287}
288
289/*
290 * \brief It initializes a network connection both from the client and the server side.
291 *
292 * In case of a client socket, this function calls socket() and connect().
293 * In the meanwhile, it checks for any socket error.
294 * If an error occurs, it writes the error message into 'errbuf'.
295 *
296 * In case of a server socket, the function calls socket(), bind() and listen().
297 *
298 * This function is usually preceeded by the sock_initaddress().
299 *
300 * \param addrinfo: pointer to an addrinfo variable which will be used to
301 * open the socket and such. This variable is the one returned by the previous call to
302 * sock_initaddress().
303 *
304 * \param server: '1' if this is a server socket, '0' otherwise.
305 *
306 * \param nconn: number of the connections that are allowed to wait into the listen() call.
307 * This value has no meanings in case of a client socket.
308 *
309 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
310 * error message. This buffer has to be at least 'errbuflen' in length.
311 * It can be NULL; in this case the error cannot be printed.
312 *
313 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
314 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
315 *
316 * \return the socket that has been opened (that has to be used in the following sockets calls)
317 * if everything is fine, INVALID_SOCKET if some errors occurred. The error message is returned
318 * in the 'errbuf' variable.
319 */
320SOCKET sock_open(struct addrinfo *addrinfo, int server, int nconn, char *errbuf, int errbuflen)
321{
322	SOCKET sock;
323#if defined(SO_NOSIGPIPE) || defined(IPV6_V6ONLY) || defined(IPV6_BINDV6ONLY)
324	int on = 1;
325#endif
326
327	sock = socket(addrinfo->ai_family, addrinfo->ai_socktype, addrinfo->ai_protocol);
328	if (sock == INVALID_SOCKET)
329	{
330		sock_geterror("socket(): ", errbuf, errbuflen);
331		return INVALID_SOCKET;
332	}
333
334	/*
335	 * Disable SIGPIPE, if we have SO_NOSIGPIPE.  We don't want to
336	 * have to deal with signals if the peer closes the connection,
337	 * especially in client programs, which may not even be aware that
338	 * they're sending to sockets.
339	 */
340#ifdef SO_NOSIGPIPE
341	if (setsockopt(sock, SOL_SOCKET, SO_NOSIGPIPE, (char *)&on,
342	    sizeof (int)) == -1)
343	{
344		sock_geterror("setsockopt(SO_NOSIGPIPE)", errbuf, errbuflen);
345		closesocket(sock);
346		return INVALID_SOCKET;
347	}
348#endif
349
350	/* This is a server socket */
351	if (server)
352	{
353#if defined(IPV6_V6ONLY) || defined(IPV6_BINDV6ONLY)
354		/*
355		 * Force the use of IPv6-only addresses.
356		 *
357		 * RFC 3493 indicates that you can support IPv4 on an
358		 * IPv6 socket:
359		 *
360		 *    https://tools.ietf.org/html/rfc3493#section-3.7
361		 *
362		 * and that this is the default behavior.  This means
363		 * that if we first create an IPv6 socket bound to the
364		 * "any" address, it is, in effect, also bound to the
365		 * IPv4 "any" address, so when we create an IPv4 socket
366		 * and try to bind it to the IPv4 "any" address, it gets
367		 * EADDRINUSE.
368		 *
369		 * Not all network stacks support IPv4 on IPv6 sockets;
370		 * pre-NT 6 Windows stacks don't support it, and the
371		 * OpenBSD stack doesn't support it for security reasons
372		 * (see the OpenBSD inet6(4) man page).  Therefore, we
373		 * don't want to rely on this behavior.
374		 *
375		 * So we try to disable it, using either the IPV6_V6ONLY
376		 * option from RFC 3493:
377		 *
378		 *    https://tools.ietf.org/html/rfc3493#section-5.3
379		 *
380		 * or the IPV6_BINDV6ONLY option from older UN*Xes.
381		 */
382#ifndef IPV6_V6ONLY
383  /* For older systems */
384  #define IPV6_V6ONLY IPV6_BINDV6ONLY
385#endif /* IPV6_V6ONLY */
386		if (addrinfo->ai_family == PF_INET6)
387		{
388			if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
389			    (char *)&on, sizeof (int)) == -1)
390			{
391				if (errbuf)
392					pcap_snprintf(errbuf, errbuflen, "setsockopt(IPV6_V6ONLY)");
393				closesocket(sock);
394				return INVALID_SOCKET;
395			}
396		}
397#endif /* defined(IPV6_V6ONLY) || defined(IPV6_BINDV6ONLY) */
398
399		/* WARNING: if the address is a mcast one, I should place the proper Win32 code here */
400		if (bind(sock, addrinfo->ai_addr, (int) addrinfo->ai_addrlen) != 0)
401		{
402			sock_geterror("bind(): ", errbuf, errbuflen);
403			closesocket(sock);
404			return INVALID_SOCKET;
405		}
406
407		if (addrinfo->ai_socktype == SOCK_STREAM)
408			if (listen(sock, nconn) == -1)
409			{
410				sock_geterror("listen(): ", errbuf, errbuflen);
411				closesocket(sock);
412				return INVALID_SOCKET;
413			}
414
415		/* server side ended */
416		return sock;
417	}
418	else	/* we're the client */
419	{
420		struct addrinfo *tempaddrinfo;
421		char *errbufptr;
422		size_t bufspaceleft;
423
424		tempaddrinfo = addrinfo;
425		errbufptr = errbuf;
426		bufspaceleft = errbuflen;
427		*errbufptr = 0;
428
429		/*
430		 * We have to loop though all the addinfo returned.
431		 * For instance, we can have both IPv6 and IPv4 addresses, but the service we're trying
432		 * to connect to is unavailable in IPv6, so we have to try in IPv4 as well
433		 */
434		while (tempaddrinfo)
435		{
436
437			if (connect(sock, tempaddrinfo->ai_addr, (int) tempaddrinfo->ai_addrlen) == -1)
438			{
439				size_t msglen;
440				char TmpBuffer[100];
441				char SocketErrorMessage[SOCK_ERRBUF_SIZE];
442
443				/*
444				 * We have to retrieve the error message before any other socket call completes, otherwise
445				 * the error message is lost
446				 */
447				sock_geterror(NULL, SocketErrorMessage, sizeof(SocketErrorMessage));
448
449				/* Returns the numeric address of the host that triggered the error */
450				sock_getascii_addrport((struct sockaddr_storage *) tempaddrinfo->ai_addr, TmpBuffer, sizeof(TmpBuffer), NULL, 0, NI_NUMERICHOST, TmpBuffer, sizeof(TmpBuffer));
451
452				pcap_snprintf(errbufptr, bufspaceleft,
453				    "Is the server properly installed on %s?  connect() failed: %s", TmpBuffer, SocketErrorMessage);
454
455				/* In case more then one 'connect' fails, we manage to keep all the error messages */
456				msglen = strlen(errbufptr);
457
458				errbufptr[msglen] = ' ';
459				errbufptr[msglen + 1] = 0;
460
461				bufspaceleft = bufspaceleft - (msglen + 1);
462				errbufptr += (msglen + 1);
463
464				tempaddrinfo = tempaddrinfo->ai_next;
465			}
466			else
467				break;
468		}
469
470		/*
471		 * Check how we exit from the previous loop
472		 * If tempaddrinfo is equal to NULL, it means that all the connect() failed.
473		 */
474		if (tempaddrinfo == NULL)
475		{
476			closesocket(sock);
477			return INVALID_SOCKET;
478		}
479		else
480			return sock;
481	}
482}
483
484/*
485 * \brief Closes the present (TCP and UDP) socket connection.
486 *
487 * This function sends a shutdown() on the socket in order to disable send() calls
488 * (while recv() ones are still allowed). Then, it closes the socket.
489 *
490 * \param sock: the socket identifier of the connection that has to be closed.
491 *
492 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
493 * error message. This buffer has to be at least 'errbuflen' in length.
494 * It can be NULL; in this case the error cannot be printed.
495 *
496 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
497 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
498 *
499 * \return '0' if everything is fine, '-1' if some errors occurred. The error message is returned
500 * in the 'errbuf' variable.
501 */
502int sock_close(SOCKET sock, char *errbuf, int errbuflen)
503{
504	/*
505	 * SHUT_WR: subsequent calls to the send function are disallowed.
506	 * For TCP sockets, a FIN will be sent after all data is sent and
507	 * acknowledged by the Server.
508	 */
509	if (shutdown(sock, SHUT_WR))
510	{
511		sock_geterror("shutdown(): ", errbuf, errbuflen);
512		/* close the socket anyway */
513		closesocket(sock);
514		return -1;
515	}
516
517	closesocket(sock);
518	return 0;
519}
520
521/*
522 * \brief Checks that the address, port and flags given are valids and it returns an 'addrinfo' structure.
523 *
524 * This function basically calls the getaddrinfo() calls, and it performs a set of sanity checks
525 * to control that everything is fine (e.g. a TCP socket cannot have a mcast address, and such).
526 * If an error occurs, it writes the error message into 'errbuf'.
527 *
528 * \param host: a pointer to a string identifying the host. It can be
529 * a host name, a numeric literal address, or NULL or "" (useful
530 * in case of a server socket which has to bind to all addresses).
531 *
532 * \param port: a pointer to a user-allocated buffer containing the network port to use.
533 *
534 * \param hints: an addrinfo variable (passed by reference) containing the flags needed to create the
535 * addrinfo structure appropriately.
536 *
537 * \param addrinfo: it represents the true returning value. This is a pointer to an addrinfo variable
538 * (passed by reference), which will be allocated by this function and returned back to the caller.
539 * This variable will be used in the next sockets calls.
540 *
541 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
542 * error message. This buffer has to be at least 'errbuflen' in length.
543 * It can be NULL; in this case the error cannot be printed.
544 *
545 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
546 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
547 *
548 * \return '0' if everything is fine, '-1' if some errors occurred. The error message is returned
549 * in the 'errbuf' variable. The addrinfo variable that has to be used in the following sockets calls is
550 * returned into the addrinfo parameter.
551 *
552 * \warning The 'addrinfo' variable has to be deleted by the programmer by calling freeaddrinfo() when
553 * it is no longer needed.
554 *
555 * \warning This function requires the 'hints' variable as parameter. The semantic of this variable is the same
556 * of the one of the corresponding variable used into the standard getaddrinfo() socket function. We suggest
557 * the programmer to look at that function in order to set the 'hints' variable appropriately.
558 */
559int sock_initaddress(const char *host, const char *port,
560    struct addrinfo *hints, struct addrinfo **addrinfo, char *errbuf, int errbuflen)
561{
562	int retval;
563
564	retval = getaddrinfo(host, port, hints, addrinfo);
565	if (retval != 0)
566	{
567		/*
568		 * if the getaddrinfo() fails, you have to use gai_strerror(), instead of using the standard
569		 * error routines (errno) in UNIX; Winsock suggests using the GetLastError() instead.
570		 */
571		if (errbuf)
572		{
573#ifdef _WIN32
574			sock_geterror("getaddrinfo(): ", errbuf, errbuflen);
575#else
576			pcap_snprintf(errbuf, errbuflen, "getaddrinfo() %s", gai_strerror(retval));
577#endif
578		}
579		return -1;
580	}
581	/*
582	 * \warning SOCKET: I should check all the accept() in order to bind to all addresses in case
583	 * addrinfo has more han one pointers
584	 */
585
586	/*
587	 * This software only supports PF_INET and PF_INET6.
588	 *
589	 * XXX - should we just check that at least *one* address is
590	 * either PF_INET or PF_INET6, and, when using the list,
591	 * ignore all addresses that are neither?  (What, no IPX
592	 * support? :-))
593	 */
594	if (((*addrinfo)->ai_family != PF_INET) &&
595	    ((*addrinfo)->ai_family != PF_INET6))
596	{
597		if (errbuf)
598			pcap_snprintf(errbuf, errbuflen, "getaddrinfo(): socket type not supported");
599		freeaddrinfo(*addrinfo);
600		*addrinfo = NULL;
601		return -1;
602	}
603
604	/*
605	 * You can't do multicast (or broadcast) TCP.
606	 */
607	if (((*addrinfo)->ai_socktype == SOCK_STREAM) &&
608	    (sock_ismcastaddr((*addrinfo)->ai_addr) == 0))
609	{
610		if (errbuf)
611			pcap_snprintf(errbuf, errbuflen, "getaddrinfo(): multicast addresses are not valid when using TCP streams");
612		freeaddrinfo(*addrinfo);
613		*addrinfo = NULL;
614		return -1;
615	}
616
617	return 0;
618}
619
620/*
621 * \brief It sends the amount of data contained into 'buffer' on the given socket.
622 *
623 * This function basically calls the send() socket function and it checks that all
624 * the data specified in 'buffer' (of size 'size') will be sent. If an error occurs,
625 * it writes the error message into 'errbuf'.
626 * In case the socket buffer does not have enough space, it loops until all data
627 * has been sent.
628 *
629 * \param socket: the connected socket currently opened.
630 *
631 * \param buffer: a char pointer to a user-allocated buffer in which data is contained.
632 *
633 * \param size: number of bytes that have to be sent.
634 *
635 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
636 * error message. This buffer has to be at least 'errbuflen' in length.
637 * It can be NULL; in this case the error cannot be printed.
638 *
639 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
640 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
641 *
642 * \return '0' if everything is fine, '-1' if an error other than
643 * "connection reset" or "peer has closed the receive side" occurred,
644 * '-2' if we got one of those errors.
645 * For errors, an error message is returned in the 'errbuf' variable.
646 */
647int sock_send(SOCKET sock, const char *buffer, size_t size,
648    char *errbuf, int errbuflen)
649{
650	int remaining;
651	ssize_t nsent;
652
653	if (size > INT_MAX)
654	{
655		if (errbuf)
656		{
657			pcap_snprintf(errbuf, errbuflen,
658			    "Can't send more than %u bytes with sock_recv",
659			    INT_MAX);
660		}
661		return -1;
662	}
663	remaining = (int)size;
664
665	do {
666#ifdef MSG_NOSIGNAL
667		/*
668		 * Send with MSG_NOSIGNAL, so that we don't get SIGPIPE
669		 * on errors on stream-oriented sockets when the other
670		 * end breaks the connection.
671		 * The EPIPE error is still returned.
672		 */
673		nsent = send(sock, buffer, remaining, MSG_NOSIGNAL);
674#else
675		nsent = send(sock, buffer, remaining, 0);
676#endif
677
678		if (nsent == -1)
679		{
680			/*
681			 * If the client closed the connection out from
682			 * under us, there's no need to log that as an
683			 * error.
684			 */
685			int errcode;
686
687#ifdef _WIN32
688			errcode = GetLastError();
689			if (errcode == WSAECONNRESET ||
690			    errcode == WSAECONNABORTED)
691			{
692				/*
693				 * WSAECONNABORTED appears to be the error
694				 * returned in Winsock when you try to send
695				 * on a connection where the peer has closed
696				 * the receive side.
697				 */
698				return -2;
699			}
700			sock_fmterror("send(): ", errcode, errbuf, errbuflen);
701#else
702			errcode = errno;
703			if (errcode == ECONNRESET || errcode == EPIPE)
704			{
705				/*
706				 * EPIPE is what's returned on UN*X when
707				 * you try to send on a connection when
708				 * the peer has closed the receive side.
709				 */
710				return -2;
711			}
712			sock_fmterror("send(): ", errcode, errbuf, errbuflen);
713#endif
714			return -1;
715		}
716
717		remaining -= nsent;
718		buffer += nsent;
719	} while (remaining != 0);
720
721	return 0;
722}
723
724/*
725 * \brief It copies the amount of data contained into 'buffer' into 'tempbuf'.
726 * and it checks for buffer overflows.
727 *
728 * This function basically copies 'size' bytes of data contained into 'buffer'
729 * into 'tempbuf', starting at offset 'offset'. Before that, it checks that the
730 * resulting buffer will not be larger	than 'totsize'. Finally, it updates
731 * the 'offset' variable in order to point to the first empty location of the buffer.
732 *
733 * In case the function is called with 'checkonly' equal to 1, it does not copy
734 * the data into the buffer. It only checks for buffer overflows and it updates the
735 * 'offset' variable. This mode can be useful when the buffer already contains the
736 * data (maybe because the producer writes directly into the target buffer), so
737 * only the buffer overflow check has to be made.
738 * In this case, both 'buffer' and 'tempbuf' can be NULL values.
739 *
740 * This function is useful in case the userland application does not know immediately
741 * all the data it has to write into the socket. This function provides a way to create
742 * the "stream" step by step, appending the new data to the old one. Then, when all the
743 * data has been bufferized, the application can call the sock_send() function.
744 *
745 * \param buffer: a char pointer to a user-allocated buffer that keeps the data
746 * that has to be copied.
747 *
748 * \param size: number of bytes that have to be copied.
749 *
750 * \param tempbuf: user-allocated buffer (of size 'totsize') in which data
751 * has to be copied.
752 *
753 * \param offset: an index into 'tempbuf' which keeps the location of its first
754 * empty location.
755 *
756 * \param totsize: total size of the buffer in which data is being copied.
757 *
758 * \param checkonly: '1' if we do not want to copy data into the buffer and we
759 * want just do a buffer ovreflow control, '0' if data has to be copied as well.
760 *
761 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
762 * error message. This buffer has to be at least 'errbuflen' in length.
763 * It can be NULL; in this case the error cannot be printed.
764 *
765 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
766 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
767 *
768 * \return '0' if everything is fine, '-1' if some errors occurred. The error message
769 * is returned in the 'errbuf' variable. When the function returns, 'tempbuf' will
770 * have the new string appended, and 'offset' will keep the length of that buffer.
771 * In case of 'checkonly == 1', data is not copied, but 'offset' is updated in any case.
772 *
773 * \warning This function assumes that the buffer in which data has to be stored is
774 * large 'totbuf' bytes.
775 *
776 * \warning In case of 'checkonly', be carefully to call this function *before* copying
777 * the data into the buffer. Otherwise, the control about the buffer overflow is useless.
778 */
779int sock_bufferize(const char *buffer, int size, char *tempbuf, int *offset, int totsize, int checkonly, char *errbuf, int errbuflen)
780{
781	if ((*offset + size) > totsize)
782	{
783		if (errbuf)
784			pcap_snprintf(errbuf, errbuflen, "Not enough space in the temporary send buffer.");
785		return -1;
786	}
787
788	if (!checkonly)
789		memcpy(tempbuf + (*offset), buffer, size);
790
791	(*offset) += size;
792
793	return 0;
794}
795
796/*
797 * \brief It waits on a connected socket and it manages to receive data.
798 *
799 * This function basically calls the recv() socket function and it checks that no
800 * error occurred. If that happens, it writes the error message into 'errbuf'.
801 *
802 * This function changes its behavior according to the 'receiveall' flag: if we
803 * want to receive exactly 'size' byte, it loops on the recv()	until all the requested
804 * data is arrived. Otherwise, it returns the data currently available.
805 *
806 * In case the socket does not have enough data available, it cycles on the recv()
807 * until the requested data (of size 'size') is arrived.
808 * In this case, it blocks until the number of bytes read is equal to 'size'.
809 *
810 * \param sock: the connected socket currently opened.
811 *
812 * \param buffer: a char pointer to a user-allocated buffer in which data has to be stored
813 *
814 * \param size: size of the allocated buffer. WARNING: this indicates the number of bytes
815 * that we are expecting to be read.
816 *
817 * \param flags:
818 *
819 *   SOCK_RECEIVALL_XXX:
820 *
821 * 	if SOCK_RECEIVEALL_NO, return as soon as some data is ready
822 *	if SOCK_RECEIVALL_YES, wait until 'size' data has been
823 *	    received (in case the socket does not have enough data available).
824 *
825 *   SOCK_EOF_XXX:
826 *
827 *	if SOCK_EOF_ISNT_ERROR, if the first read returns 0, just return 0,
828 *	    and return an error on any subsequent read that returns 0;
829 *	if SOCK_EOF_IS_ERROR, if any read returns 0, return an error.
830 *
831 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
832 * error message. This buffer has to be at least 'errbuflen' in length.
833 * It can be NULL; in this case the error cannot be printed.
834 *
835 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
836 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
837 *
838 * \return the number of bytes read if everything is fine, '-1' if some errors occurred.
839 * The error message is returned in the 'errbuf' variable.
840 */
841
842int sock_recv(SOCKET sock, void *buffer, size_t size, int flags,
843    char *errbuf, int errbuflen)
844{
845	char *bufp = buffer;
846	int remaining;
847	ssize_t nread;
848
849	if (size == 0)
850	{
851		SOCK_DEBUG_MESSAGE("I have been requested to read zero bytes");
852		return 0;
853	}
854	if (size > INT_MAX)
855	{
856		if (errbuf)
857		{
858			pcap_snprintf(errbuf, errbuflen,
859			    "Can't read more than %u bytes with sock_recv",
860			    INT_MAX);
861		}
862		return -1;
863	}
864
865	bufp = (char *) buffer;
866	remaining = (int) size;
867
868	/*
869	 * We don't use MSG_WAITALL because it's not supported in
870	 * Win32.
871	 */
872	for (;;) {
873		nread = recv(sock, bufp, remaining, 0);
874
875		if (nread == -1)
876		{
877#ifndef _WIN32
878			if (errno == EINTR)
879				return -3;
880#endif
881			sock_geterror("recv(): ", errbuf, errbuflen);
882			return -1;
883		}
884
885		if (nread == 0)
886		{
887			if ((flags & SOCK_EOF_IS_ERROR) ||
888			    (remaining != (int) size))
889			{
890				/*
891				 * Either we've already read some data,
892				 * or we're always supposed to return
893				 * an error on EOF.
894				 */
895				if (errbuf)
896				{
897					pcap_snprintf(errbuf, errbuflen,
898					    "The other host terminated the connection.");
899				}
900				return -1;
901			}
902			else
903				return 0;
904		}
905
906		/*
907		 * Do we want to read the amount requested, or just return
908		 * what we got?
909		 */
910		if (!(flags & SOCK_RECEIVEALL_YES))
911		{
912			/*
913			 * Just return what we got.
914			 */
915			return (int) nread;
916		}
917
918		bufp += nread;
919		remaining -= nread;
920
921		if (remaining == 0)
922			return (int) size;
923	}
924}
925
926/*
927 * Receives a datagram from a socket.
928 *
929 * Returns the size of the datagram on success or -1 on error.
930 */
931int sock_recv_dgram(SOCKET sock, void *buffer, size_t size,
932    char *errbuf, int errbuflen)
933{
934	ssize_t nread;
935#ifndef _WIN32
936	struct msghdr message;
937	struct iovec iov;
938#endif
939
940	if (size == 0)
941	{
942		SOCK_DEBUG_MESSAGE("I have been requested to read zero bytes");
943		return 0;
944	}
945	if (size > INT_MAX)
946	{
947		if (errbuf)
948		{
949			pcap_snprintf(errbuf, errbuflen,
950			    "Can't read more than %u bytes with sock_recv_dgram",
951			    INT_MAX);
952		}
953		return -1;
954	}
955
956	/*
957	 * This should be a datagram socket, so we should get the
958	 * entire datagram in one recv() or recvmsg() call, and
959	 * don't need to loop.
960	 */
961#ifdef _WIN32
962	nread = recv(sock, buffer, size, 0);
963	if (nread == SOCKET_ERROR)
964	{
965		/*
966		 * To quote the MSDN documentation for recv(),
967		 * "If the datagram or message is larger than
968		 * the buffer specified, the buffer is filled
969		 * with the first part of the datagram, and recv
970		 * generates the error WSAEMSGSIZE. For unreliable
971		 * protocols (for example, UDP) the excess data is
972		 * lost..."
973		 *
974		 * So if the message is bigger than the buffer
975		 * supplied to us, the excess data is discarded,
976		 * and we'll report an error.
977		 */
978		sock_geterror("recv(): ", errbuf, errbuflen);
979		return -1;
980	}
981#else /* _WIN32 */
982	/*
983	 * The Single UNIX Specification says that a recv() on
984	 * a socket for a message-oriented protocol will discard
985	 * the excess data.  It does *not* indicate that the
986	 * receive will fail with, for example, EMSGSIZE.
987	 *
988	 * Therefore, we use recvmsg(), which appears to be
989	 * the only way to get a "message truncated" indication
990	 * when receiving a message for a message-oriented
991	 * protocol.
992	 */
993	message.msg_name = NULL;	/* we don't care who it's from */
994	message.msg_namelen = 0;
995	iov.iov_base = buffer;
996	iov.iov_len = size;
997	message.msg_iov = &iov;
998	message.msg_iovlen = 1;
999#ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
1000	message.msg_control = NULL;	/* we don't care about control information */
1001	message.msg_controllen = 0;
1002#endif
1003#ifdef HAVE_STRUCT_MSGHDR_MSG_FLAGS
1004	message.msg_flags = 0;
1005#endif
1006	nread = recvmsg(sock, &message, 0);
1007	if (nread == -1)
1008	{
1009		if (errno == EINTR)
1010			return -3;
1011		sock_geterror("recv(): ", errbuf, errbuflen);
1012		return -1;
1013	}
1014#ifdef HAVE_STRUCT_MSGHDR_MSG_FLAGS
1015	/*
1016	 * XXX - Solaris supports this, but only if you ask for the
1017	 * X/Open version of recvmsg(); should we use that, or will
1018	 * that cause other problems?
1019	 */
1020	if (message.msg_flags & MSG_TRUNC)
1021	{
1022		/*
1023		 * Message was bigger than the specified buffer size.
1024		 *
1025		 * Report this as an error, as the Microsoft documentation
1026		 * implies we'd do in a similar case on Windows.
1027		 */
1028		pcap_snprintf(errbuf, errbuflen, "recv(): Message too long");
1029		return -1;
1030	}
1031#endif /* HAVE_STRUCT_MSGHDR_MSG_FLAGS */
1032#endif /* _WIN32 */
1033
1034	/*
1035	 * The size we're reading fits in an int, so the return value
1036	 * will fit in an int.
1037	 */
1038	return (int)nread;
1039}
1040
1041/*
1042 * \brief It discards N bytes that are currently waiting to be read on the current socket.
1043 *
1044 * This function is useful in case we receive a message we cannot understand (e.g.
1045 * wrong version number when receiving a network packet), so that we have to discard all
1046 * data before reading a new message.
1047 *
1048 * This function will read 'size' bytes from the socket and discard them.
1049 * It defines an internal buffer in which data will be copied; however, in case
1050 * this buffer is not large enough, it will cycle in order to read everything as well.
1051 *
1052 * \param sock: the connected socket currently opened.
1053 *
1054 * \param size: number of bytes that have to be discarded.
1055 *
1056 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
1057 * error message. This buffer has to be at least 'errbuflen' in length.
1058 * It can be NULL; in this case the error cannot be printed.
1059 *
1060 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
1061 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
1062 *
1063 * \return '0' if everything is fine, '-1' if some errors occurred.
1064 * The error message is returned in the 'errbuf' variable.
1065 */
1066int sock_discard(SOCKET sock, int size, char *errbuf, int errbuflen)
1067{
1068#define TEMP_BUF_SIZE 32768
1069
1070	char buffer[TEMP_BUF_SIZE];		/* network buffer, to be used when the message is discarded */
1071
1072	/*
1073	 * A static allocation avoids the need of a 'malloc()' each time we want to discard a message
1074	 * Our feeling is that a buffer if 32KB is enough for most of the application;
1075	 * in case this is not enough, the "while" loop discards the message by calling the
1076	 * sockrecv() several times.
1077	 * We do not want to create a bigger variable because this causes the program to exit on
1078	 * some platforms (e.g. BSD)
1079	 */
1080	while (size > TEMP_BUF_SIZE)
1081	{
1082		if (sock_recv(sock, buffer, TEMP_BUF_SIZE, SOCK_RECEIVEALL_YES, errbuf, errbuflen) == -1)
1083			return -1;
1084
1085		size -= TEMP_BUF_SIZE;
1086	}
1087
1088	/*
1089	 * If there is still data to be discarded
1090	 * In this case, the data can fit into the temporary buffer
1091	 */
1092	if (size)
1093	{
1094		if (sock_recv(sock, buffer, size, SOCK_RECEIVEALL_YES, errbuf, errbuflen) == -1)
1095			return -1;
1096	}
1097
1098	SOCK_DEBUG_MESSAGE("I'm currently discarding data\n");
1099
1100	return 0;
1101}
1102
1103/*
1104 * \brief Checks that one host (identified by the sockaddr_storage structure) belongs to an 'allowed list'.
1105 *
1106 * This function is useful after an accept() call in order to check if the connecting
1107 * host is allowed to connect to me. To do that, we have a buffer that keeps the list of the
1108 * allowed host; this function checks the sockaddr_storage structure of the connecting host
1109 * against this host list, and it returns '0' is the host is included in this list.
1110 *
1111 * \param hostlist: pointer to a string that contains the list of the allowed host.
1112 *
1113 * \param sep: a string that keeps the separators used between the hosts (for example the
1114 * space character) in the host list.
1115 *
1116 * \param from: a sockaddr_storage structure, as it is returned by the accept() call.
1117 *
1118 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
1119 * error message. This buffer has to be at least 'errbuflen' in length.
1120 * It can be NULL; in this case the error cannot be printed.
1121 *
1122 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
1123 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
1124 *
1125 * \return It returns:
1126 * - '1' if the host list is empty
1127 * - '0' if the host belongs to the host list (and therefore it is allowed to connect)
1128 * - '-1' in case the host does not belong to the host list (and therefore it is not allowed to connect
1129 * - '-2' in case or error. The error message is returned in the 'errbuf' variable.
1130 */
1131int sock_check_hostlist(char *hostlist, const char *sep, struct sockaddr_storage *from, char *errbuf, int errbuflen)
1132{
1133	/* checks if the connecting host is among the ones allowed */
1134	if ((hostlist) && (hostlist[0]))
1135	{
1136		char *token;					/* temp, needed to separate items into the hostlist */
1137		struct addrinfo *addrinfo, *ai_next;
1138		char *temphostlist;
1139		char *lasts;
1140
1141		/*
1142		 * The problem is that strtok modifies the original variable by putting '0' at the end of each token
1143		 * So, we have to create a new temporary string in which the original content is kept
1144		 */
1145		temphostlist = strdup(hostlist);
1146		if (temphostlist == NULL)
1147		{
1148			sock_geterror("sock_check_hostlist(), malloc() failed", errbuf, errbuflen);
1149			return -2;
1150		}
1151
1152		token = pcap_strtok_r(temphostlist, sep, &lasts);
1153
1154		/* it avoids a warning in the compilation ('addrinfo used but not initialized') */
1155		addrinfo = NULL;
1156
1157		while (token != NULL)
1158		{
1159			struct addrinfo hints;
1160			int retval;
1161
1162			addrinfo = NULL;
1163			memset(&hints, 0, sizeof(struct addrinfo));
1164			hints.ai_family = PF_UNSPEC;
1165			hints.ai_socktype = SOCK_STREAM;
1166
1167			retval = getaddrinfo(token, "0", &hints, &addrinfo);
1168			if (retval != 0)
1169			{
1170				if (errbuf)
1171					pcap_snprintf(errbuf, errbuflen, "getaddrinfo() %s", gai_strerror(retval));
1172
1173				SOCK_DEBUG_MESSAGE(errbuf);
1174
1175				/* Get next token */
1176				token = pcap_strtok_r(NULL, sep, &lasts);
1177				continue;
1178			}
1179
1180			/* ai_next is required to preserve the content of addrinfo, in order to deallocate it properly */
1181			ai_next = addrinfo;
1182			while (ai_next)
1183			{
1184				if (sock_cmpaddr(from, (struct sockaddr_storage *) ai_next->ai_addr) == 0)
1185				{
1186					free(temphostlist);
1187					freeaddrinfo(addrinfo);
1188					return 0;
1189				}
1190
1191				/*
1192				 * If we are here, it means that the current address does not matches
1193				 * Let's try with the next one in the header chain
1194				 */
1195				ai_next = ai_next->ai_next;
1196			}
1197
1198			freeaddrinfo(addrinfo);
1199			addrinfo = NULL;
1200
1201			/* Get next token */
1202			token = pcap_strtok_r(NULL, sep, &lasts);
1203		}
1204
1205		if (addrinfo)
1206		{
1207			freeaddrinfo(addrinfo);
1208			addrinfo = NULL;
1209		}
1210
1211		if (errbuf)
1212			pcap_snprintf(errbuf, errbuflen, "The host is not in the allowed host list. Connection refused.");
1213
1214		free(temphostlist);
1215		return -1;
1216	}
1217
1218	/* No hostlist, so we have to return 'empty list' */
1219	return 1;
1220}
1221
1222/*
1223 * \brief Compares two addresses contained into two sockaddr_storage structures.
1224 *
1225 * This function is useful to compare two addresses, given their internal representation,
1226 * i.e. an sockaddr_storage structure.
1227 *
1228 * The two structures do not need to be sockaddr_storage; you can have both 'sockaddr_in' and
1229 * sockaddr_in6, properly acsted in order to be compliant to the function interface.
1230 *
1231 * This function will return '0' if the two addresses matches, '-1' if not.
1232 *
1233 * \param first: a sockaddr_storage structure, (for example the one that is returned by an
1234 * accept() call), containing the first address to compare.
1235 *
1236 * \param second: a sockaddr_storage structure containing the second address to compare.
1237 *
1238 * \return '0' if the addresses are equal, '-1' if they are different.
1239 */
1240int sock_cmpaddr(struct sockaddr_storage *first, struct sockaddr_storage *second)
1241{
1242	if (first->ss_family == second->ss_family)
1243	{
1244		if (first->ss_family == AF_INET)
1245		{
1246			if (memcmp(&(((struct sockaddr_in *) first)->sin_addr),
1247				&(((struct sockaddr_in *) second)->sin_addr),
1248				sizeof(struct in_addr)) == 0)
1249				return 0;
1250		}
1251		else /* address family is AF_INET6 */
1252		{
1253			if (memcmp(&(((struct sockaddr_in6 *) first)->sin6_addr),
1254				&(((struct sockaddr_in6 *) second)->sin6_addr),
1255				sizeof(struct in6_addr)) == 0)
1256				return 0;
1257		}
1258	}
1259
1260	return -1;
1261}
1262
1263/*
1264 * \brief It gets the address/port the system picked for this socket (on connected sockets).
1265 *
1266 * It is used to return the address and port the server picked for our socket on the local machine.
1267 * It works only on:
1268 * - connected sockets
1269 * - server sockets
1270 *
1271 * On unconnected client sockets it does not work because the system dynamically chooses a port
1272 * only when the socket calls a send() call.
1273 *
1274 * \param sock: the connected socket currently opened.
1275 *
1276 * \param address: it contains the address that will be returned by the function. This buffer
1277 * must be properly allocated by the user. The address can be either literal or numeric depending
1278 * on the value of 'Flags'.
1279 *
1280 * \param addrlen: the length of the 'address' buffer.
1281 *
1282 * \param port: it contains the port that will be returned by the function. This buffer
1283 * must be properly allocated by the user.
1284 *
1285 * \param portlen: the length of the 'port' buffer.
1286 *
1287 * \param flags: a set of flags (the ones defined into the getnameinfo() standard socket function)
1288 * that determine if the resulting address must be in numeric / literal form, and so on.
1289 *
1290 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
1291 * error message. This buffer has to be at least 'errbuflen' in length.
1292 * It can be NULL; in this case the error cannot be printed.
1293 *
1294 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
1295 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
1296 *
1297 * \return It returns '-1' if this function succeeds, '0' otherwise.
1298 * The address and port corresponding are returned back in the buffers 'address' and 'port'.
1299 * In any case, the returned strings are '0' terminated.
1300 *
1301 * \warning If the socket is using a connectionless protocol, the address may not be available
1302 * until I/O occurs on the socket.
1303 */
1304int sock_getmyinfo(SOCKET sock, char *address, int addrlen, char *port, int portlen, int flags, char *errbuf, int errbuflen)
1305{
1306	struct sockaddr_storage mysockaddr;
1307	socklen_t sockaddrlen;
1308
1309
1310	sockaddrlen = sizeof(struct sockaddr_storage);
1311
1312	if (getsockname(sock, (struct sockaddr *) &mysockaddr, &sockaddrlen) == -1)
1313	{
1314		sock_geterror("getsockname(): ", errbuf, errbuflen);
1315		return 0;
1316	}
1317
1318	/* Returns the numeric address of the host that triggered the error */
1319	return sock_getascii_addrport(&mysockaddr, address, addrlen, port, portlen, flags, errbuf, errbuflen);
1320}
1321
1322/*
1323 * \brief It retrieves two strings containing the address and the port of a given 'sockaddr' variable.
1324 *
1325 * This function is basically an extended version of the inet_ntop(), which does not exist in
1326 * Winsock because the same result can be obtained by using the getnameinfo().
1327 * However, differently from inet_ntop(), this function is able to return also literal names
1328 * (e.g. 'localhost') dependently from the 'Flags' parameter.
1329 *
1330 * The function accepts a sockaddr_storage variable (which can be returned by several functions
1331 * like bind(), connect(), accept(), and more) and it transforms its content into a 'human'
1332 * form. So, for instance, it is able to translate an hex address (stored in binary form) into
1333 * a standard IPv6 address like "::1".
1334 *
1335 * The behavior of this function depends on the parameters we have in the 'Flags' variable, which
1336 * are the ones allowed in the standard getnameinfo() socket function.
1337 *
1338 * \param sockaddr: a 'sockaddr_in' or 'sockaddr_in6' structure containing the address that
1339 * need to be translated from network form into the presentation form. This structure must be
1340 * zero-ed prior using it, and the address family field must be filled with the proper value.
1341 * The user must cast any 'sockaddr_in' or 'sockaddr_in6' structures to 'sockaddr_storage' before
1342 * calling this function.
1343 *
1344 * \param address: it contains the address that will be returned by the function. This buffer
1345 * must be properly allocated by the user. The address can be either literal or numeric depending
1346 * on the value of 'Flags'.
1347 *
1348 * \param addrlen: the length of the 'address' buffer.
1349 *
1350 * \param port: it contains the port that will be returned by the function. This buffer
1351 * must be properly allocated by the user.
1352 *
1353 * \param portlen: the length of the 'port' buffer.
1354 *
1355 * \param flags: a set of flags (the ones defined into the getnameinfo() standard socket function)
1356 * that determine if the resulting address must be in numeric / literal form, and so on.
1357 *
1358 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
1359 * error message. This buffer has to be at least 'errbuflen' in length.
1360 * It can be NULL; in this case the error cannot be printed.
1361 *
1362 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
1363 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
1364 *
1365 * \return It returns '-1' if this function succeeds, '0' otherwise.
1366 * The address and port corresponding to the given SockAddr are returned back in the buffers 'address'
1367 * and 'port'.
1368 * In any case, the returned strings are '0' terminated.
1369 */
1370int sock_getascii_addrport(const struct sockaddr_storage *sockaddr, char *address, int addrlen, char *port, int portlen, int flags, char *errbuf, int errbuflen)
1371{
1372	socklen_t sockaddrlen;
1373	int retval;					/* Variable that keeps the return value; */
1374
1375	retval = -1;
1376
1377#ifdef _WIN32
1378	if (sockaddr->ss_family == AF_INET)
1379		sockaddrlen = sizeof(struct sockaddr_in);
1380	else
1381		sockaddrlen = sizeof(struct sockaddr_in6);
1382#else
1383	sockaddrlen = sizeof(struct sockaddr_storage);
1384#endif
1385
1386	if ((flags & NI_NUMERICHOST) == 0)	/* Check that we want literal names */
1387	{
1388		if ((sockaddr->ss_family == AF_INET6) &&
1389			(memcmp(&((struct sockaddr_in6 *) sockaddr)->sin6_addr, "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0", sizeof(struct in6_addr)) == 0))
1390		{
1391			if (address)
1392				strlcpy(address, SOCKET_NAME_NULL_DAD, addrlen);
1393			return retval;
1394		}
1395	}
1396
1397	if (getnameinfo((struct sockaddr *) sockaddr, sockaddrlen, address, addrlen, port, portlen, flags) != 0)
1398	{
1399		/* If the user wants to receive an error message */
1400		if (errbuf)
1401		{
1402			sock_geterror("getnameinfo(): ", errbuf, errbuflen);
1403			errbuf[errbuflen - 1] = 0;
1404		}
1405
1406		if (address)
1407		{
1408			strlcpy(address, SOCKET_NO_NAME_AVAILABLE, addrlen);
1409			address[addrlen - 1] = 0;
1410		}
1411
1412		if (port)
1413		{
1414			strlcpy(port, SOCKET_NO_PORT_AVAILABLE, portlen);
1415			port[portlen - 1] = 0;
1416		}
1417
1418		retval = 0;
1419	}
1420
1421	return retval;
1422}
1423
1424/*
1425 * \brief It translates an address from the 'presentation' form into the 'network' form.
1426 *
1427 * This function basically replaces inet_pton(), which does not exist in Winsock because
1428 * the same result can be obtained by using the getaddrinfo().
1429 * An additional advantage is that 'Address' can be both a numeric address (e.g. '127.0.0.1',
1430 * like in inet_pton() ) and a literal name (e.g. 'localhost').
1431 *
1432 * This function does the reverse job of sock_getascii_addrport().
1433 *
1434 * \param address: a zero-terminated string which contains the name you have to
1435 * translate. The name can be either literal (e.g. 'localhost') or numeric (e.g. '::1').
1436 *
1437 * \param sockaddr: a user-allocated sockaddr_storage structure which will contains the
1438 * 'network' form of the requested address.
1439 *
1440 * \param addr_family: a constant which can assume the following values:
1441 * - 'AF_INET' if we want to ping an IPv4 host
1442 * - 'AF_INET6' if we want to ping an IPv6 host
1443 * - 'AF_UNSPEC' if we do not have preferences about the protocol used to ping the host
1444 *
1445 * \param errbuf: a pointer to an user-allocated buffer that will contain the complete
1446 * error message. This buffer has to be at least 'errbuflen' in length.
1447 * It can be NULL; in this case the error cannot be printed.
1448 *
1449 * \param errbuflen: length of the buffer that will contains the error. The error message cannot be
1450 * larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
1451 *
1452 * \return '-1' if the translation succeeded, '-2' if there was some non critical error, '0'
1453 * otherwise. In case it fails, the content of the SockAddr variable remains unchanged.
1454 * A 'non critical error' can occur in case the 'Address' is a literal name, which can be mapped
1455 * to several network addresses (e.g. 'foo.bar.com' => '10.2.2.2' and '10.2.2.3'). In this case
1456 * the content of the SockAddr parameter will be the address corresponding to the first mapping.
1457 *
1458 * \warning The sockaddr_storage structure MUST be allocated by the user.
1459 */
1460int sock_present2network(const char *address, struct sockaddr_storage *sockaddr, int addr_family, char *errbuf, int errbuflen)
1461{
1462	int retval;
1463	struct addrinfo *addrinfo;
1464	struct addrinfo hints;
1465
1466	memset(&hints, 0, sizeof(hints));
1467
1468	hints.ai_family = addr_family;
1469
1470	if ((retval = sock_initaddress(address, "22222" /* fake port */, &hints, &addrinfo, errbuf, errbuflen)) == -1)
1471		return 0;
1472
1473	if (addrinfo->ai_family == PF_INET)
1474		memcpy(sockaddr, addrinfo->ai_addr, sizeof(struct sockaddr_in));
1475	else
1476		memcpy(sockaddr, addrinfo->ai_addr, sizeof(struct sockaddr_in6));
1477
1478	if (addrinfo->ai_next != NULL)
1479	{
1480		freeaddrinfo(addrinfo);
1481
1482		if (errbuf)
1483			pcap_snprintf(errbuf, errbuflen, "More than one socket requested; using the first one returned");
1484		return -2;
1485	}
1486
1487	freeaddrinfo(addrinfo);
1488	return -1;
1489}
1490