/*
* Copyright (c) 2002 - 2003
* NetGroup, Politecnico di Torino (Italy)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the Politecnico di Torino nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <config.h>
/*
* \file sockutils.c
*
* The goal of this file is to provide a common set of primitives for socket
* manipulation.
*
* Although the socket interface defined in the RFC 2553 (and its updates)
* is excellent, there are still differences between the behavior of those
* routines on UN*X and Windows, and between UN*Xes.
*
* These calls provide an interface similar to the socket interface, but
* that hides the differences between operating systems. It does not
* attempt to significantly improve on the socket interface in other
* ways.
*/
#include "ftmacros.h"
#include <string.h>
#include <errno.h> /* for the errno variable */
#include <stdio.h> /* for the stderr file */
#include <stdlib.h> /* for malloc() and free() */
#include <limits.h> /* for INT_MAX */
#include "pcap-int.h"
#include "sockutils.h"
#include "portability.h"
#ifdef _WIN32
/*
* Winsock initialization.
*
* Ask for Winsock 2.2.
*/
#define WINSOCK_MAJOR_VERSION 2
#define WINSOCK_MINOR_VERSION 2
static int sockcount = 0; /*!< Variable that allows calling the WSAStartup() only one time */
#endif
/* Some minor differences between UNIX and Win32 */
#ifdef _WIN32
#define SHUT_WR SD_SEND /* The control code for shutdown() is different in Win32 */
#endif
/* Size of the buffer that has to keep error messages */
#define SOCK_ERRBUF_SIZE 1024
/* Constants; used in order to keep strings here */
#define SOCKET_NO_NAME_AVAILABLE "No name available"
#define SOCKET_NO_PORT_AVAILABLE "No port available"
#define SOCKET_NAME_NULL_DAD "Null address (possibly DAD Phase)"
/*
* On UN*X, send() and recv() return ssize_t.
*
* On Windows, send() and recv() return an int.
*
* With MSVC, there *is* no ssize_t.
*
* With MinGW, there is an ssize_t type; it is either an int (32 bit)
* or a long long (64 bit).
*
* So, on Windows, if we don't have ssize_t defined, define it as an
* int, so we can use it, on all platforms, as the type of variables
* that hold the return values from send() and recv().
*/
#if defined(_WIN32) && !defined(_SSIZE_T_DEFINED)
typedef int ssize_t;
#endif
/****************************************************
* *
* Locally defined functions *
* *
****************************************************/
static int sock_ismcastaddr(const struct sockaddr *saddr);
/****************************************************
* *
* Function bodies *
* *
****************************************************/
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
const uint8_t *fuzzBuffer;
size_t fuzzSize;
size_t fuzzPos;
void sock_initfuzz(const uint8_t *Data, size_t Size) {
fuzzPos = 0;
fuzzSize = Size;
fuzzBuffer = Data;
}
static int fuzz_recv(char *bufp, int remaining) {
if (remaining > fuzzSize - fuzzPos) {
remaining = fuzzSize - fuzzPos;
}
if (fuzzPos < fuzzSize) {
memcpy(bufp, fuzzBuffer + fuzzPos, remaining);
}
fuzzPos += remaining;
return remaining;
}
#endif
int sock_geterrcode(void)
{
#ifdef _WIN32
return GetLastError();
#else
return errno;
#endif
}
/*
* Format an error message given an errno value (UN*X) or a Winsock error
* (Windows).
*/
void sock_vfmterrmsg(char *errbuf, size_t errbuflen, int errcode,
const char *fmt, va_list ap)
{
if (errbuf == NULL)
return;
#ifdef _WIN32
pcapint_vfmt_errmsg_for_win32_err(errbuf, errbuflen, errcode,
fmt, ap);
#else
pcapint_vfmt_errmsg_for_errno(errbuf, errbuflen, errcode,
fmt, ap);
#endif
}
void sock_fmterrmsg(char *errbuf, size_t errbuflen, int errcode,
const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
sock_vfmterrmsg(errbuf, errbuflen, errcode, fmt, ap);
va_end(ap);
}
/*
* Format an error message for the last socket error.
*/
void sock_geterrmsg(char *errbuf, size_t errbuflen, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
sock_vfmterrmsg(errbuf, errbuflen, sock_geterrcode(), fmt, ap);
va_end(ap);
}
/*
* Types of error.
*
* These are sorted by how likely they are to be the "underlying" problem,
* so that lower-rated errors for a given address in a given family
* should not overwrite higher-rated errors for another address in that
* family, and higher-rated errors should overwrite lower-rated errors.
*/
typedef enum {
SOCK_CONNERR, /* connection error */
SOCK_HOSTERR, /* host error */
SOCK_NETERR, /* network error */
SOCK_AFNOTSUPERR, /* address family not supported */
SOCK_UNKNOWNERR, /* unknown error */
SOCK_NOERR /* no error */
} sock_errtype;
static sock_errtype sock_geterrtype(int errcode)
{
switch (errcode) {
#ifdef _WIN32
case WSAECONNRESET:
case WSAECONNABORTED:
case WSAECONNREFUSED:
#else
case ECONNRESET:
case ECONNABORTED:
case ECONNREFUSED:
#endif
/*
* Connection error; this means the problem is probably
* that there's no server set up on the remote machine,
* or that it is set up, but it's IPv4-only or IPv6-only
* and we're trying the wrong address family.
*
* These overwrite all other errors, as they indicate
* that, even if something else went wrong in another
* attempt, this probably wouldn't work even if the
* other problems were fixed.
*/
return (SOCK_CONNERR);
#ifdef _WIN32
case WSAENETUNREACH:
case WSAETIMEDOUT:
case WSAEHOSTDOWN:
case WSAEHOSTUNREACH:
#else
case ENETUNREACH:
case ETIMEDOUT:
case EHOSTDOWN:
case EHOSTUNREACH:
#endif
/*
* Network errors that could be IPv4-specific, IPv6-
* specific, or present with both.
*
* Don't overwrite connection errors, but overwrite
* everything else.
*/
return (SOCK_HOSTERR);
#ifdef _WIN32
case WSAENETDOWN:
case WSAENETRESET:
#else
case ENETDOWN:
case ENETRESET:
#endif
/*
* Network error; this means we don't know whether
* there's a server set up on the remote machine,
* and we don't have a reason to believe that IPv6
* any worse or better than IPv4.
*
* These probably indicate a local failure, e.g.
* an interface is down.
*
* Don't overwrite connection errors or host errors,
* but overwrite everything else.
*/
return (SOCK_NETERR);
#ifdef _WIN32
case WSAEAFNOSUPPORT:
#else
case EAFNOSUPPORT:
#endif
/*
* "Address family not supported" probably means
* "No soup^WIPv6 for you!".
*
* Don't overwrite connection errors, host errors, or
* network errors (none of which we should get for this
* address family if it's not supported), but overwrite
* everything else.
*/
return (SOCK_AFNOTSUPERR);
default:
/*
* Anything else.
*
* Don't overwrite any errors.
*/
return (SOCK_UNKNOWNERR);
}
}
/*
* \brief This function initializes the socket mechanism if it hasn't
* already been initialized or reinitializes it after it has been
* cleaned up.
*
* On UN*Xes, it doesn't need to do anything; on Windows, it needs to
* initialize Winsock.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain
* the complete error message. This buffer has to be at least 'errbuflen'
* in length. It can be NULL; in this case no error message is supplied.
*
* \param errbuflen: length of the buffer that will contains the error.
* The error message cannot be larger than 'errbuflen - 1' because the
* last char is reserved for the string terminator.
*
* \return '0' if everything is fine, '-1' if some errors occurred. The
* error message is returned in the buffer pointed to by 'errbuf' variable.
*/
#ifdef _WIN32
int sock_init(char *errbuf, int errbuflen)
{
if (sockcount == 0)
{
WSADATA wsaData; /* helper variable needed to initialize Winsock */
if (WSAStartup(MAKEWORD(WINSOCK_MAJOR_VERSION,
WINSOCK_MINOR_VERSION), &wsaData) != 0)
{
if (errbuf)
snprintf(errbuf, errbuflen, "Failed to initialize Winsock\n");
return -1;
}
}
sockcount++;
return 0;
}
#else
int sock_init(char *errbuf _U_, int errbuflen _U_)
{
/*
* Nothing to do on UN*Xes.
*/
return 0;
}
#endif
/*
* \brief This function cleans up the socket mechanism if we have no
* sockets left open.
*
* On UN*Xes, it doesn't need to do anything; on Windows, it needs
* to clean up Winsock.
*
* \return No error values.
*/
void sock_cleanup(void)
{
#ifdef _WIN32
sockcount--;
if (sockcount == 0)
WSACleanup();
#endif
}
/*
* \brief It checks if the sockaddr variable contains a multicast address.
*
* \return '0' if the address is multicast, '-1' if it is not.
*/
static int sock_ismcastaddr(const struct sockaddr *saddr)
{
if (saddr->sa_family == PF_INET)
{
const struct sockaddr_in *saddr4 = (const struct sockaddr_in *) saddr;
if (IN_MULTICAST(ntohl(saddr4->sin_addr.s_addr))) return 0;
else return -1;
}
else
{
const struct sockaddr_in6 *saddr6 = (const struct sockaddr_in6 *) saddr;
if (IN6_IS_ADDR_MULTICAST(&saddr6->sin6_addr)) return 0;
else return -1;
}
}
struct addr_status {
struct addrinfo *info;
int errcode;
sock_errtype errtype;
};
/*
* Sort by IPv4 address vs. IPv6 address.
*/
static int compare_addrs_to_try_by_address_family(const void *a, const void *b)
{
const struct addr_status *addr_a = (const struct addr_status *)a;
const struct addr_status *addr_b = (const struct addr_status *)b;
return addr_a->info->ai_family - addr_b->info->ai_family;
}
/*
* Sort by error type and, within a given error type, by error code and,
* within a given error code, by IPv4 address vs. IPv6 address.
*/
static int compare_addrs_to_try_by_status(const void *a, const void *b)
{
const struct addr_status *addr_a = (const struct addr_status *)a;
const struct addr_status *addr_b = (const struct addr_status *)b;
if (addr_a->errtype == addr_b->errtype)
{
if (addr_a->errcode == addr_b->errcode)
{
return addr_a->info->ai_family - addr_b->info->ai_family;
}
return addr_a->errcode - addr_b->errcode;
}
return addr_a->errtype - addr_b->errtype;
}
static PCAP_SOCKET sock_create_socket(struct addrinfo *addrinfo, char *errbuf,
int errbuflen)
{
PCAP_SOCKET sock;
#ifdef SO_NOSIGPIPE
int on = 1;
#endif
sock = socket(addrinfo->ai_family, addrinfo->ai_socktype,
addrinfo->ai_protocol);
if (sock == INVALID_SOCKET)
{
sock_geterrmsg(errbuf, errbuflen, "socket() failed");
return INVALID_SOCKET;
}
/*
* Disable SIGPIPE, if we have SO_NOSIGPIPE. We don't want to
* have to deal with signals if the peer closes the connection,
* especially in client programs, which may not even be aware that
* they're sending to sockets.
*/
#ifdef SO_NOSIGPIPE
if (setsockopt(sock, SOL_SOCKET, SO_NOSIGPIPE, (char *)&on,
sizeof (int)) == -1)
{
sock_geterrmsg(errbuf, errbuflen,
"setsockopt(SO_NOSIGPIPE) failed");
closesocket(sock);
return INVALID_SOCKET;
}
#endif
return sock;
}
/*
* \brief It initializes a network connection both from the client and the server side.
*
* In case of a client socket, this function calls socket() and connect().
* In the meanwhile, it checks for any socket error.
* If an error occurs, it writes the error message into 'errbuf'.
*
* In case of a server socket, the function calls socket(), bind() and listen().
*
* This function is usually preceded by the sock_initaddress().
*
* \param host: for client sockets, the host name to which we're trying
* to connect.
*
* \param addrinfo: pointer to an addrinfo variable which will be used to
* open the socket and such. This variable is the one returned by the previous call to
* sock_initaddress().
*
* \param server: '1' if this is a server socket, '0' otherwise.
*
* \param nconn: number of the connections that are allowed to wait into the listen() call.
* This value has no meanings in case of a client socket.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return the socket that has been opened (that has to be used in the following sockets calls)
* if everything is fine, INVALID_SOCKET if some errors occurred. The error message is returned
* in the 'errbuf' variable.
*/
PCAP_SOCKET sock_open(const char *host, struct addrinfo *addrinfo,
int server, int nconn, char *errbuf, int errbuflen)
{
PCAP_SOCKET sock;
/* This is a server socket */
if (server)
{
int on;
/*
* Attempt to create the socket.
*/
sock = sock_create_socket(addrinfo, errbuf, errbuflen);
if (sock == INVALID_SOCKET)
{
return INVALID_SOCKET;
}
/*
* Allow a new server to bind the socket after the old one
* exited, even if lingering sockets are still present.
*
* Don't treat an error as a failure.
*/
on = 1;
(void)setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
(char *)&on, sizeof (on));
#if defined(IPV6_V6ONLY) || defined(IPV6_BINDV6ONLY)
/*
* Force the use of IPv6-only addresses.
*
* RFC 3493 indicates that you can support IPv4 on an
* IPv6 socket:
*
*
https://tools.ietf.org/html/rfc3493#section-3.7
*
* and that this is the default behavior. This means
* that if we first create an IPv6 socket bound to the
* "any" address, it is, in effect, also bound to the
* IPv4 "any" address, so when we create an IPv4 socket
* and try to bind it to the IPv4 "any" address, it gets
* EADDRINUSE.
*
* Not all network stacks support IPv4 on IPv6 sockets;
* pre-NT 6 Windows stacks don't support it, and the
* OpenBSD stack doesn't support it for security reasons
* (see the OpenBSD inet6(4) man page). Therefore, we
* don't want to rely on this behavior.
*
* So we try to disable it, using either the IPV6_V6ONLY
* option from RFC 3493:
*
*
https://tools.ietf.org/html/rfc3493#section-5.3
*
* or the IPV6_BINDV6ONLY option from older UN*Xes.
*/
#ifndef IPV6_V6ONLY
/* For older systems */
#define IPV6_V6ONLY IPV6_BINDV6ONLY
#endif /* IPV6_V6ONLY */
if (addrinfo->ai_family == PF_INET6)
{
on = 1;
if (setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
(char *)&on, sizeof (int)) == -1)
{
if (errbuf)
snprintf(errbuf, errbuflen, "setsockopt(IPV6_V6ONLY)");
closesocket(sock);
return INVALID_SOCKET;
}
}
#endif /* defined(IPV6_V6ONLY) || defined(IPV6_BINDV6ONLY) */
/* WARNING: if the address is a mcast one, I should place the proper Win32 code here */
if (bind(sock, addrinfo->ai_addr, (int) addrinfo->ai_addrlen) != 0)
{
sock_geterrmsg(errbuf, errbuflen, "bind() failed");
closesocket(sock);
return INVALID_SOCKET;
}
if (addrinfo->ai_socktype == SOCK_STREAM)
if (listen(sock, nconn) == -1)
{
sock_geterrmsg(errbuf, errbuflen,
"listen() failed");
closesocket(sock);
return INVALID_SOCKET;
}
/* server side ended */
return sock;
}
else /* we're the client */
{
struct addr_status *addrs_to_try;
struct addrinfo *tempaddrinfo;
size_t numaddrinfos;
size_t i;
int current_af = AF_UNSPEC;
/*
* We have to loop though all the addrinfos returned.
* For instance, we can have both IPv6 and IPv4 addresses,
* but the service we're trying to connect to is unavailable
* in IPv6, so we have to try in IPv4 as well.
*
* How many addrinfos do we have?
*/
numaddrinfos = 0;
for (tempaddrinfo = addrinfo; tempaddrinfo != NULL;
tempaddrinfo = tempaddrinfo->ai_next)
{
numaddrinfos++;
}
if (numaddrinfos == 0)
{
snprintf(errbuf, errbuflen,
"There are no addresses in the address list");
return INVALID_SOCKET;
}
/*
* Allocate an array of struct addr_status and fill it in.
*/
addrs_to_try = calloc(numaddrinfos, sizeof *addrs_to_try);
if (addrs_to_try == NULL)
{
snprintf(errbuf, errbuflen,
"Out of memory connecting to %s", host);
return INVALID_SOCKET;
}
for (tempaddrinfo = addrinfo, i = 0; tempaddrinfo != NULL;
tempaddrinfo = tempaddrinfo->ai_next, i++)
{
addrs_to_try[i].info = tempaddrinfo;
addrs_to_try[i].errcode = 0;
addrs_to_try[i].errtype = SOCK_NOERR;
}
/*
* Sort the structures to put the IPv4 addresses before the
* IPv6 addresses; we will have to create an IPv4 socket
* for the IPv4 addresses and an IPv6 socket for the IPv6
* addresses (one of the arguments to socket() is the
* address/protocol family to use, and IPv4 and IPv6 are
* separate address/protocol families).
*/
qsort(addrs_to_try, numaddrinfos, sizeof *addrs_to_try,
compare_addrs_to_try_by_address_family);
/* Start out with no socket. */
sock = INVALID_SOCKET;
/*
* Now try them all.
*/
for (i = 0; i < numaddrinfos; i++)
{
tempaddrinfo = addrs_to_try[i].info;
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
break;
#endif
/*
* If we have a socket, but it's for a
* different address family, close it.
*/
if (sock != INVALID_SOCKET &&
current_af != tempaddrinfo->ai_family)
{
closesocket(sock);
sock = INVALID_SOCKET;
}
/*
* If we don't have a socket, open one
* for *this* address's address family.
*/
if (sock == INVALID_SOCKET)
{
sock = sock_create_socket(tempaddrinfo,
errbuf, errbuflen);
if (sock == INVALID_SOCKET)
{
free(addrs_to_try);
return INVALID_SOCKET;
}
}
if (connect(sock, tempaddrinfo->ai_addr, (int) tempaddrinfo->ai_addrlen) == -1)
{
addrs_to_try[i].errcode = sock_geterrcode();
addrs_to_try[i].errtype =
sock_geterrtype(addrs_to_try[i].errcode);
}
else
break;
}
/*
* Check how we exited from the previous loop.
* If tempaddrinfo is equal to NULL, it means that all
* the connect() attempts failed. Construct an
* error message.
*/
if (i == numaddrinfos)
{
int same_error_for_all;
int first_error;
closesocket(sock);
/*
* Sort the statuses to group together categories
* of errors, errors within categories, and
* address families within error sets.
*/
qsort(addrs_to_try, numaddrinfos, sizeof *addrs_to_try,
compare_addrs_to_try_by_status);
/*
* Are all the errors the same?
*/
same_error_for_all = 1;
first_error = addrs_to_try[0].errcode;
for (i = 1; i < numaddrinfos; i++)
{
if (addrs_to_try[i].errcode != first_error)
{
same_error_for_all = 0;
break;
}
}
if (same_error_for_all) {
/*
* Yes. No need to show the IP
* addresses.
*/
if (addrs_to_try[0].errtype == SOCK_CONNERR) {
/*
* Connection error; note that
* the daemon might not be set
* up correctly, or set up at all.
*/
sock_fmterrmsg(errbuf, errbuflen,
addrs_to_try[0].errcode,
"Is the server properly installed? Cannot connect to %s",
host);
} else {
sock_fmterrmsg(errbuf, errbuflen,
addrs_to_try[0].errcode,
"Cannot connect to %s", host);
}
} else {
/*
* Show all the errors and the IP addresses
* to which they apply.
*/
char *errbufptr;
size_t bufspaceleft;
size_t msglen;
snprintf(errbuf, errbuflen,
"Connect to %s failed: ", host);
msglen = strlen(errbuf);
errbufptr = errbuf + msglen;
bufspaceleft = errbuflen - msglen;
for (i = 0; i < numaddrinfos &&
addrs_to_try[i].errcode != SOCK_NOERR;
i++)
{
/*
* Get the string for the address
* and port that got this error.
*/
sock_getascii_addrport((struct sockaddr_storage *) addrs_to_try[i].info->ai_addr,
errbufptr, (int)bufspaceleft,
NULL, 0, NI_NUMERICHOST, NULL, 0);
msglen = strlen(errbuf);
errbufptr = errbuf + msglen;
bufspaceleft = errbuflen - msglen;
if (i + 1 < numaddrinfos &&
addrs_to_try[i + 1].errcode == addrs_to_try[i].errcode)
{
/*
* There's another error
* after this, and it has
* the same error code.
*
* Append a comma, as the
* list of addresses with
* this error has another
* entry.
*/
snprintf(errbufptr, bufspaceleft,
", ");
}
else
{
/*
* Either there are no
* more errors after this,
* or the next error is
* different.
*
* Append a colon and
* the message for tis
* error, followed by a
* comma if there are
* more errors.
*/
sock_fmterrmsg(errbufptr,
bufspaceleft,
addrs_to_try[i].errcode,
"%s", "");
msglen = strlen(errbuf);
errbufptr = errbuf + msglen;
bufspaceleft = errbuflen - msglen;
if (i + 1 < numaddrinfos &&
addrs_to_try[i + 1].errcode != SOCK_NOERR)
{
/*
* More to come.
*/
snprintf(errbufptr,
bufspaceleft,
", ");
}
}
msglen = strlen(errbuf);
errbufptr = errbuf + msglen;
bufspaceleft = errbuflen - msglen;
}
}
free(addrs_to_try);
return INVALID_SOCKET;
}
else
{
free(addrs_to_try);
return sock;
}
}
}
/*
* \brief Closes the present (TCP and UDP) socket connection.
*
* This function sends a shutdown() on the socket in order to disable send() calls
* (while recv() ones are still allowed). Then, it closes the socket.
*
* \param sock: the socket identifier of the connection that has to be closed.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return '0' if everything is fine, '-1' if some errors occurred. The error message is returned
* in the 'errbuf' variable.
*/
int sock_close(PCAP_SOCKET sock, char *errbuf, int errbuflen)
{
/*
* SHUT_WR: subsequent calls to the send function are disallowed.
* For TCP sockets, a FIN will be sent after all data is sent and
* acknowledged by the Server.
*/
if (shutdown(sock, SHUT_WR))
{
sock_geterrmsg(errbuf, errbuflen, "shutdown() failed");
/* close the socket anyway */
closesocket(sock);
return -1;
}
closesocket(sock);
return 0;
}
/*
* gai_strerror() has some problems:
*
* 1) on Windows, Microsoft explicitly says it's not thread-safe;
* 2) on UN*X, the Single UNIX Specification doesn't say it *is*
* thread-safe, so an implementation might use a static buffer
* for unknown error codes;
* 3) the error message for the most likely error, EAI_NONAME, is
* truly horrible on several platforms ("nodename nor servname
* provided, or not known"? It's typically going to be "not
* known", not "oopsie, I passed null pointers for the host name
* and service name", not to mention they forgot the "neither");
*
* so we roll our own.
*/
static void
get_gai_errstring(char *errbuf, int errbuflen, const char *prefix, int err,
const char *hostname, const char *portname)
{
char hostport[PCAP_ERRBUF_SIZE];
if (hostname != NULL && portname != NULL)
snprintf(hostport, PCAP_ERRBUF_SIZE, "host and port %s:%s",
hostname, portname);
else if (hostname != NULL)
snprintf(hostport, PCAP_ERRBUF_SIZE, "host %s",
hostname);
else if (portname != NULL)
snprintf(hostport, PCAP_ERRBUF_SIZE, "port %s",
portname);
else
snprintf(hostport, PCAP_ERRBUF_SIZE, "<no host or port!>");
switch (err)
{
#ifdef EAI_ADDRFAMILY
case EAI_ADDRFAMILY:
snprintf(errbuf, errbuflen,
"%sAddress family for %s not supported",
prefix, hostport);
break;
#endif
case EAI_AGAIN:
snprintf(errbuf, errbuflen,
"%s%s could not be resolved at this time",
prefix, hostport);
break;
case EAI_BADFLAGS:
snprintf(errbuf, errbuflen,
"%sThe ai_flags parameter for looking up %s had an invalid value",
prefix, hostport);
break;
case EAI_FAIL:
snprintf(errbuf, errbuflen,
"%sA non-recoverable error occurred when attempting to resolve %s",
prefix, hostport);
break;
case EAI_FAMILY:
snprintf(errbuf, errbuflen,
"%sThe address family for looking up %s was not recognized",
prefix, hostport);
break;
case EAI_MEMORY:
snprintf(errbuf, errbuflen,
"%sOut of memory trying to allocate storage when looking up %s",
prefix, hostport);
break;
/*
* RFC 2553 had both EAI_NODATA and EAI_NONAME.
*
* RFC 3493 has only EAI_NONAME.
*
* Some implementations define EAI_NODATA and EAI_NONAME
* to the same value, others don't. If EAI_NODATA is
* defined and isn't the same as EAI_NONAME, we handle
* EAI_NODATA.
*/
#if defined(EAI_NODATA) && EAI_NODATA != EAI_NONAME
case EAI_NODATA:
snprintf(errbuf, errbuflen,
"%sNo address associated with %s",
prefix, hostport);
break;
#endif
case EAI_NONAME:
snprintf(errbuf, errbuflen,
"%sThe %s couldn't be resolved",
prefix, hostport);
break;
case EAI_SERVICE:
snprintf(errbuf, errbuflen,
"%sThe service value specified when looking up %s as not recognized for the socket type",
prefix, hostport);
break;
case EAI_SOCKTYPE:
snprintf(errbuf, errbuflen,
"%sThe socket type specified when looking up %s as not recognized",
prefix, hostport);
break;
#ifdef EAI_SYSTEM
case EAI_SYSTEM:
/*
* Assumed to be UN*X.
*/
pcapint_fmt_errmsg_for_errno(errbuf, errbuflen, errno,
"%sAn error occurred when looking up %s",
prefix, hostport);
break;
#endif
#ifdef EAI_BADHINTS
case EAI_BADHINTS:
snprintf(errbuf, errbuflen,
"%sInvalid value for hints when looking up %s",
prefix, hostport);
break;
#endif
#ifdef EAI_PROTOCOL
case EAI_PROTOCOL:
snprintf(errbuf, errbuflen,
"%sResolved protocol when looking up %s is unknown",
prefix, hostport);
break;
#endif
#ifdef EAI_OVERFLOW
case EAI_OVERFLOW:
snprintf(errbuf, errbuflen,
"%sArgument buffer overflow when looking up %s",
prefix, hostport);
break;
#endif
default:
snprintf(errbuf, errbuflen,
"%sgetaddrinfo() error %d when looking up %s",
prefix, err, hostport);
break;
}
}
/*
* \brief Checks that the address, port and flags given are valid and it returns an 'addrinfo' structure.
*
* This function basically calls the getaddrinfo() calls, and it performs a set of sanity checks
* to control that everything is fine (e.g. a TCP socket cannot have a mcast address, and such).
* If an error occurs, it writes the error message into 'errbuf'.
*
* \param host: a pointer to a string identifying the host. It can be
* a host name, a numeric literal address, or NULL or "" (useful
* in case of a server socket which has to bind to all addresses).
*
* \param port: a pointer to a user-allocated buffer containing the network port to use.
*
* \param hints: an addrinfo variable (passed by reference) containing the flags needed to create the
* addrinfo structure appropriately.
*
* \param addrinfo: it represents the true returning value. This is a pointer to an addrinfo variable
* (passed by reference), which will be allocated by this function and returned back to the caller.
* This variable will be used in the next sockets calls.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return a pointer to the first element in a list of addrinfo structures
* if everything is fine, NULL if some errors occurred. The error message
* is returned in the 'errbuf' variable.
*
* \warning The list of addrinfo structures returned has to be deleted by
* the programmer by calling freeaddrinfo() when it is no longer needed.
*
* \warning This function requires the 'hints' variable as parameter. The semantic of this variable is the same
* of the one of the corresponding variable used into the standard getaddrinfo() socket function. We suggest
* the programmer to look at that function in order to set the 'hints' variable appropriately.
*/
struct addrinfo *sock_initaddress(const char *host, const char *port,
struct addrinfo *hints, char *errbuf, int errbuflen)
{
struct addrinfo *addrinfo;
int retval;
/*
* We allow both the host and port to be null, but getaddrinfo()
* is not guaranteed to do so; to handle that, if port is null,
* we provide "0" as the port number.
*
* This results in better error messages from get_gai_errstring(),
* as those messages won't talk about a problem with the port if
* no port was specified.
*/
retval = getaddrinfo(host, port == NULL ? "0" : port, hints, &addrinfo);
if (retval != 0)
{
/*
* That call failed.
* Determine whether the problem is that the host is bad.
*/
if (errbuf)
{
if (host != NULL && port != NULL) {
/*
* Try with just a host, to distinguish
* between "host is bad" and "port is
* bad".
*/
int try_retval;
try_retval = getaddrinfo(host, NULL, hints,
&addrinfo);
if (try_retval == 0) {
/*
* Worked with just the host,
* so assume the problem is
* with the port.
*
* Free up the address info first.
*/
freeaddrinfo(addrinfo);
get_gai_errstring(errbuf, errbuflen,
"", retval, NULL, port);
} else {
/*
* Didn't work with just the host,
* so assume the problem is
* with the host; we assume
* the original error indicates
* the underlying problem.
*/
get_gai_errstring(errbuf, errbuflen,
"", retval, host, NULL);
}
} else {
/*
* Either the host or port was null, so
* there's nothing to determine; report
* the error from the original call.
*/
get_gai_errstring(errbuf, errbuflen, "",
retval, host, port);
}
}
return NULL;
}
/*
* \warning SOCKET: I should check all the accept() in order to bind to all addresses in case
* addrinfo has more han one pointers
*/
/*
* This software only supports PF_INET and PF_INET6.
*
* XXX - should we just check that at least *one* address is
* either PF_INET or PF_INET6, and, when using the list,
* ignore all addresses that are neither? (What, no IPX
* support? :-))
*/
if ((addrinfo->ai_family != PF_INET) &&
(addrinfo->ai_family != PF_INET6))
{
if (errbuf)
snprintf(errbuf, errbuflen, "getaddrinfo(): socket type not supported");
freeaddrinfo(addrinfo);
return NULL;
}
/*
* You can't do multicast (or broadcast) TCP.
*/
if ((addrinfo->ai_socktype == SOCK_STREAM) &&
(sock_ismcastaddr(addrinfo->ai_addr) == 0))
{
if (errbuf)
snprintf(errbuf, errbuflen, "getaddrinfo(): multicast addresses are not valid when using TCP streams");
freeaddrinfo(addrinfo);
return NULL;
}
return addrinfo;
}
/*
* \brief It sends the amount of data contained into 'buffer' on the given socket.
*
* This function basically calls the send() socket function and it checks that all
* the data specified in 'buffer' (of size 'size') will be sent. If an error occurs,
* it writes the error message into 'errbuf'.
* In case the socket buffer does not have enough space, it loops until all data
* has been sent.
*
* \param socket: the connected socket currently opened.
*
* \param buffer: a char pointer to a user-allocated buffer in which data is contained.
*
* \param size: number of bytes that have to be sent.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return '0' if everything is fine, '-1' if an error other than
* "connection reset" or "peer has closed the receive side" occurred,
* '-2' if we got one of those errors.
* For errors, an error message is returned in the 'errbuf' variable.
*/
int sock_send(PCAP_SOCKET sock, SSL *ssl _U_NOSSL_, const char *buffer,
size_t size, char *errbuf, int errbuflen)
{
int remaining;
ssize_t nsent;
if (size > INT_MAX)
{
if (errbuf)
{
snprintf(errbuf, errbuflen,
"Can't send more than %u bytes with sock_send",
INT_MAX);
}
return -1;
}
remaining = (int)size;
do {
#ifdef HAVE_OPENSSL
if (ssl) return ssl_send(ssl, buffer, remaining, errbuf, errbuflen);
#endif
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
nsent = remaining;
#else
#ifdef MSG_NOSIGNAL
/*
* Send with MSG_NOSIGNAL, so that we don't get SIGPIPE
* on errors on stream-oriented sockets when the other
* end breaks the connection.
* The EPIPE error is still returned.
*/
nsent = send(sock, buffer, remaining, MSG_NOSIGNAL);
#else
nsent = send(sock, buffer, remaining, 0);
#endif
#endif //FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
if (nsent == -1)
{
/*
* If the client closed the connection out from
* under us, there's no need to log that as an
* error.
*/
int errcode;
#ifdef _WIN32
errcode = GetLastError();
if (errcode == WSAECONNRESET ||
errcode == WSAECONNABORTED)
{
/*
* WSAECONNABORTED appears to be the error
* returned in Winsock when you try to send
* on a connection where the peer has closed
* the receive side.
*/
return -2;
}
sock_fmterrmsg(errbuf, errbuflen, errcode,
"send() failed");
#else
errcode = errno;
if (errcode == ECONNRESET || errcode == EPIPE)
{
/*
* EPIPE is what's returned on UN*X when
* you try to send on a connection when
* the peer has closed the receive side.
*/
return -2;
}
sock_fmterrmsg(errbuf, errbuflen, errcode,
"send() failed");
#endif
return -1;
}
remaining -= nsent;
buffer += nsent;
} while (remaining != 0);
return 0;
}
/*
* \brief It copies the amount of data contained in 'data' into 'outbuf'.
* and it checks for buffer overflows.
*
* This function basically copies 'size' bytes of data contained in 'data'
* into 'outbuf', starting at offset 'offset'. Before that, it checks that the
* resulting buffer will not be larger than 'totsize'. Finally, it updates
* the 'offset' variable in order to point to the first empty location of the buffer.
*
* In case the function is called with 'checkonly' equal to 1, it does not copy
* the data into the buffer. It only checks for buffer overflows and it updates the
* 'offset' variable. This mode can be useful when the buffer already contains the
* data (maybe because the producer writes directly into the target buffer), so
* only the buffer overflow check has to be made.
* In this case, both 'data' and 'outbuf' can be NULL values.
*
* This function is useful in case the userland application does not know immediately
* all the data it has to write into the socket. This function provides a way to create
* the "stream" step by step, appending the new data to the old one. Then, when all the
* data has been bufferized, the application can call the sock_send() function.
*
* \param data: a void pointer to the data that has to be copied.
*
* \param size: number of bytes that have to be copied.
*
* \param outbuf: user-allocated buffer (of size 'totsize') into which data
* has to be copied.
*
* \param offset: an index into 'outbuf' which keeps the location of its first
* empty location.
*
* \param totsize: total size of the buffer into which data is being copied.
*
* \param checkonly: '1' if we do not want to copy data into the buffer and we
* want just do a buffer overflow control, '0' if data has to be copied as well.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return '0' if everything is fine, '-1' if some errors occurred. The error message
* is returned in the 'errbuf' variable. When the function returns, 'outbuf' will
* have the new string appended, and 'offset' will keep the length of that buffer.
* In case of 'checkonly == 1', data is not copied, but 'offset' is updated in any case.
*
* \warning This function assumes that the buffer in which data has to be stored is
* large 'totbuf' bytes.
*
* \warning In case of 'checkonly', be carefully to call this function *before* copying
* the data into the buffer. Otherwise, the control about the buffer overflow is useless.
*/
int sock_bufferize(const void *data, int size, char *outbuf, int *offset, int totsize, int checkonly, char *errbuf, int errbuflen)
{
if ((*offset + size) > totsize)
{
if (errbuf)
snprintf(errbuf, errbuflen, "Not enough space in the temporary send buffer.");
return -1;
}
if (!checkonly)
memcpy(outbuf + (*offset), data, size);
(*offset) += size;
return 0;
}
/*
* \brief It waits on a connected socket and it manages to receive data.
*
* This function basically calls the recv() socket function and it checks that no
* error occurred. If that happens, it writes the error message into 'errbuf'.
*
* This function changes its behavior according to the 'receiveall' flag: if we
* want to receive exactly 'size' byte, it loops on the recv() until all the requested
* data is arrived. Otherwise, it returns the data currently available.
*
* In case the socket does not have enough data available, it cycles on the recv()
* until the requested data (of size 'size') is arrived.
* In this case, it blocks until the number of bytes read is equal to 'size'.
*
* \param sock: the connected socket currently opened.
*
* \param buffer: a char pointer to a user-allocated buffer in which data has to be stored
*
* \param size: size of the allocated buffer. WARNING: this indicates the number of bytes
* that we are expecting to be read.
*
* \param flags:
*
* SOCK_RECEIVALL_XXX:
*
* if SOCK_RECEIVEALL_NO, return as soon as some data is ready
* if SOCK_RECEIVALL_YES, wait until 'size' data has been
* received (in case the socket does not have enough data available).
*
* SOCK_EOF_XXX:
*
* if SOCK_EOF_ISNT_ERROR, if the first read returns 0, just return 0,
* and return an error on any subsequent read that returns 0;
* if SOCK_EOF_IS_ERROR, if any read returns 0, return an error.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return the number of bytes read if everything is fine, '-1' if some errors occurred.
* The error message is returned in the 'errbuf' variable.
*/
int sock_recv(PCAP_SOCKET sock, SSL *ssl _U_NOSSL_, void *buffer, size_t size,
int flags, char *errbuf, int errbuflen)
{
int recv_flags = 0;
char *bufp = buffer;
int remaining;
ssize_t nread;
if (size == 0)
{
return 0;
}
if (size > INT_MAX)
{
if (errbuf)
{
snprintf(errbuf, errbuflen,
"Can't read more than %u bytes with sock_recv",
INT_MAX);
}
return -1;
}
if (flags & SOCK_MSG_PEEK)
recv_flags |= MSG_PEEK;
bufp = (char *) buffer;
remaining = (int) size;
/*
* We don't use MSG_WAITALL because it's not supported in
* Win32.
*/
for (;;) {
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
nread = fuzz_recv(bufp, remaining);
#elif defined(HAVE_OPENSSL)
if (ssl)
{
/*
* XXX - what about MSG_PEEK?
*/
nread = ssl_recv(ssl, bufp, remaining, errbuf, errbuflen);
if (nread == -2) return -1;
}
else
nread = recv(sock, bufp, remaining, recv_flags);
#else
nread = recv(sock, bufp, remaining, recv_flags);
#endif
if (nread == -1)
{
#ifndef _WIN32
if (errno == EINTR)
return -3;
#endif
sock_geterrmsg(errbuf, errbuflen, "recv() failed");
return -1;
}
if (nread == 0)
{
if ((flags & SOCK_EOF_IS_ERROR) ||
(remaining != (int) size))
{
/*
* Either we've already read some data,
* or we're always supposed to return
* an error on EOF.
*/
if (errbuf)
{
snprintf(errbuf, errbuflen,
"The other host terminated the connection.");
}
return -1;
}
else
return 0;
}
/*
* Do we want to read the amount requested, or just return
* what we got?
*/
if (!(flags & SOCK_RECEIVEALL_YES))
{
/*
* Just return what we got.
*/
return (int) nread;
}
bufp += nread;
remaining -= nread;
if (remaining == 0)
return (int) size;
}
}
/*
* Receives a datagram from a socket.
*
* Returns the size of the datagram on success or -1 on error.
*/
int sock_recv_dgram(PCAP_SOCKET sock, SSL *ssl _U_NOSSL_, void *buffer,
size_t size, char *errbuf, int errbuflen)
{
ssize_t nread;
#ifndef _WIN32
struct msghdr message;
struct iovec iov;
#endif
if (size == 0)
{
return 0;
}
if (size > INT_MAX)
{
if (errbuf)
{
snprintf(errbuf, errbuflen,
"Can't read more than %u bytes with sock_recv_dgram",
INT_MAX);
}
return -1;
}
#ifdef HAVE_OPENSSL
// TODO: DTLS
if (ssl)
{
snprintf(errbuf, errbuflen, "DTLS not implemented yet");
return -1;
}
#endif
/*
* This should be a datagram socket, so we should get the
* entire datagram in one recv() or recvmsg() call, and
* don't need to loop.
*/
#ifdef _WIN32
nread = recv(sock, buffer, (int)size, 0);
if (nread == SOCKET_ERROR)
{
/*
* To quote the MSDN documentation for recv(),
* "If the datagram or message is larger than
* the buffer specified, the buffer is filled
* with the first part of the datagram, and recv
* generates the error WSAEMSGSIZE. For unreliable
* protocols (for example, UDP) the excess data is
* lost..."
*
* So if the message is bigger than the buffer
* supplied to us, the excess data is discarded,
* and we'll report an error.
*/
sock_fmterrmsg(errbuf, errbuflen, sock_geterrcode(),
"recv() failed");
return -1;
}
#else /* _WIN32 */
/*
* The Single UNIX Specification says that a recv() on
* a socket for a message-oriented protocol will discard
* the excess data. It does *not* indicate that the
* receive will fail with, for example, EMSGSIZE.
*
* Therefore, we use recvmsg(), which appears to be
* the only way to get a "message truncated" indication
* when receiving a message for a message-oriented
* protocol.
*/
message.msg_name = NULL; /* we don't care who it's from */
message.msg_namelen = 0;
iov.iov_base = buffer;
iov.iov_len = size;
message.msg_iov = &iov;
message.msg_iovlen = 1;
#ifdef HAVE_STRUCT_MSGHDR_MSG_CONTROL
message.msg_control = NULL; /* we don't care about control information */
message.msg_controllen = 0;
#endif
#ifdef HAVE_STRUCT_MSGHDR_MSG_FLAGS
message.msg_flags = 0;
#endif
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
nread = fuzz_recv(buffer, size);
#else
nread = recvmsg(sock, &message, 0);
#endif
if (nread == -1)
{
if (errno == EINTR)
return -3;
sock_geterrmsg(errbuf, errbuflen, "recv() failed");
return -1;
}
#ifdef HAVE_STRUCT_MSGHDR_MSG_FLAGS
/*
* XXX - Solaris supports this, but only if you ask for the
* X/Open version of recvmsg(); should we use that, or will
* that cause other problems?
*/
if (message.msg_flags & MSG_TRUNC)
{
/*
* Message was bigger than the specified buffer size.
*
* Report this as an error, as the Microsoft documentation
* implies we'd do in a similar case on Windows.
*/
snprintf(errbuf, errbuflen, "recv(): Message too long");
return -1;
}
#endif /* HAVE_STRUCT_MSGHDR_MSG_FLAGS */
#endif /* _WIN32 */
/*
* The size we're reading fits in an int, so the return value
* will fit in an int.
*/
return (int)nread;
}
/*
* \brief It discards N bytes that are currently waiting to be read on the current socket.
*
* This function is useful in case we receive a message we cannot understand (e.g.
* wrong version number when receiving a network packet), so that we have to discard all
* data before reading a new message.
*
* This function will read 'size' bytes from the socket and discard them.
* It defines an internal buffer in which data will be copied; however, in case
* this buffer is not large enough, it will cycle in order to read everything as well.
*
* \param sock: the connected socket currently opened.
*
* \param size: number of bytes that have to be discarded.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return '0' if everything is fine, '-1' if some errors occurred.
* The error message is returned in the 'errbuf' variable.
*/
int sock_discard(PCAP_SOCKET sock, SSL *ssl, int size, char *errbuf,
int errbuflen)
{
#define TEMP_BUF_SIZE 32768
char buffer[TEMP_BUF_SIZE]; /* network buffer, to be used when the message is discarded */
/*
* A static allocation avoids the need of a 'malloc()' each time we want to discard a message
* Our feeling is that a buffer if 32KB is enough for most of the application;
* in case this is not enough, the "while" loop discards the message by calling the
* sockrecv() several times.
* We do not want to create a bigger variable because this causes the program to exit on
* some platforms (e.g. BSD)
*/
while (size > TEMP_BUF_SIZE)
{
if (sock_recv(sock, ssl, buffer, TEMP_BUF_SIZE, SOCK_RECEIVEALL_YES, errbuf, errbuflen) == -1)
return -1;
size -= TEMP_BUF_SIZE;
}
/*
* If there is still data to be discarded
* In this case, the data can fit into the temporary buffer
*/
if (size)
{
if (sock_recv(sock, ssl, buffer, size, SOCK_RECEIVEALL_YES, errbuf, errbuflen) == -1)
return -1;
}
return 0;
}
/*
* \brief Checks that one host (identified by the sockaddr_storage structure) belongs to an 'allowed list'.
*
* This function is useful after an accept() call in order to check if the connecting
* host is allowed to connect to me. To do that, we have a buffer that keeps the list of the
* allowed host; this function checks the sockaddr_storage structure of the connecting host
* against this host list, and it returns '0' is the host is included in this list.
*
* \param hostlist: pointer to a string that contains the list of the allowed host.
*
* \param sep: a string that keeps the separators used between the hosts (for example the
* space character) in the host list.
*
* \param from: a sockaddr_storage structure, as it is returned by the accept() call.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return It returns:
* - '1' if the host list is empty
* - '0' if the host belongs to the host list (and therefore it is allowed to connect)
* - '-1' in case the host does not belong to the host list (and therefore it is not allowed to connect
* - '-2' in case or error. The error message is returned in the 'errbuf' variable.
*/
int sock_check_hostlist(const char *hostlist, const char *sep, struct sockaddr_storage *from, char *errbuf, int errbuflen)
{
/* checks if the connecting host is among the ones allowed */
if ((hostlist) && (hostlist[0]))
{
char *token; /* temp, needed to separate items into the hostlist */
struct addrinfo *addrinfo, *ai_next;
char *temphostlist;
char *lasts;
int getaddrinfo_failed = 0;
/*
* The problem is that strtok modifies the original variable by putting '0' at the end of each token
* So, we have to create a new temporary string in which the original content is kept
*/
temphostlist = strdup(hostlist);
if (temphostlist == NULL)
{
sock_geterrmsg(errbuf, errbuflen,
"sock_check_hostlist(), malloc() failed");
return -2;
}
token = pcapint_strtok_r(temphostlist, sep, &lasts);
/* it avoids a warning in the compilation ('addrinfo used but not initialized') */
addrinfo = NULL;
while (token != NULL)
{
struct addrinfo hints;
int retval;
addrinfo = NULL;
memset(&hints, 0, sizeof(struct addrinfo));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
retval = getaddrinfo(token, NULL, &hints, &addrinfo);
if (retval != 0)
{
if (errbuf)
get_gai_errstring(errbuf, errbuflen,
"Allowed host list error: ",
retval, token, NULL);
/*
* Note that at least one call to getaddrinfo()
* failed.
*/
getaddrinfo_failed = 1;
/* Get next token */
token = pcapint_strtok_r(NULL, sep, &lasts);
continue;
}
/* ai_next is required to preserve the content of addrinfo, in order to deallocate it properly */
ai_next = addrinfo;
while (ai_next)
{
if (sock_cmpaddr(from, (struct sockaddr_storage *) ai_next->ai_addr) == 0)
{
free(temphostlist);
freeaddrinfo(addrinfo);
return 0;
}
/*
* If we are here, it means that the current address does not matches
* Let's try with the next one in the header chain
*/
ai_next = ai_next->ai_next;
}
freeaddrinfo(addrinfo);
addrinfo = NULL;
/* Get next token */
token = pcapint_strtok_r(NULL, sep, &lasts);
}
if (addrinfo)
{
freeaddrinfo(addrinfo);
addrinfo = NULL;
}
free(temphostlist);
if (getaddrinfo_failed) {
/*
* At least one getaddrinfo() call failed;
* treat that as an error, so rpcapd knows
* that it should log it locally as well
* as telling the client about it.
*/
return -2;
} else {
/*
* All getaddrinfo() calls succeeded, but
* the host wasn't in the list.
*/
if (errbuf)
snprintf(errbuf, errbuflen, "The host is not in the allowed host list. Connection refused.");
return -1;
}
}
/* No hostlist, so we have to return 'empty list' */
return 1;
}
/*
* \brief Compares two addresses contained into two sockaddr_storage structures.
*
* This function is useful to compare two addresses, given their internal representation,
* i.e. an sockaddr_storage structure.
*
* The two structures do not need to be sockaddr_storage; you can have both 'sockaddr_in' and
* sockaddr_in6, properly casted in order to be compliant to the function interface.
*
* This function will return '0' if the two addresses matches, '-1' if not.
*
* \param first: a sockaddr_storage structure, (for example the one that is returned by an
* accept() call), containing the first address to compare.
*
* \param second: a sockaddr_storage structure containing the second address to compare.
*
* \return '0' if the addresses are equal, '-1' if they are different.
*/
int sock_cmpaddr(struct sockaddr_storage *first, struct sockaddr_storage *second)
{
if (first->ss_family == second->ss_family)
{
if (first->ss_family == AF_INET)
{
if (memcmp(&(((struct sockaddr_in *) first)->sin_addr),
&(((struct sockaddr_in *) second)->sin_addr),
sizeof(struct in_addr)) == 0)
return 0;
}
else /* address family is AF_INET6 */
{
if (memcmp(&(((struct sockaddr_in6 *) first)->sin6_addr),
&(((struct sockaddr_in6 *) second)->sin6_addr),
sizeof(struct in6_addr)) == 0)
return 0;
}
}
return -1;
}
/*
* \brief It gets the address/port the system picked for this socket (on connected sockets).
*
* It is used to return the address and port the server picked for our socket on the local machine.
* It works only on:
* - connected sockets
* - server sockets
*
* On unconnected client sockets it does not work because the system dynamically chooses a port
* only when the socket calls a send() call.
*
* \param sock: the connected socket currently opened.
*
* \param address: it contains the address that will be returned by the function. This buffer
* must be properly allocated by the user. The address can be either literal or numeric depending
* on the value of 'Flags'.
*
* \param addrlen: the length of the 'address' buffer.
*
* \param port: it contains the port that will be returned by the function. This buffer
* must be properly allocated by the user.
*
* \param portlen: the length of the 'port' buffer.
*
* \param flags: a set of flags (the ones defined into the getnameinfo() standard socket function)
* that determine if the resulting address must be in numeric / literal form, and so on.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return It returns '-1' if this function succeeds, '0' otherwise.
* The address and port corresponding are returned back in the buffers 'address' and 'port'.
* In any case, the returned strings are '0' terminated.
*
* \warning If the socket is using a connectionless protocol, the address may not be available
* until I/O occurs on the socket.
*/
int sock_getmyinfo(PCAP_SOCKET sock, char *address, int addrlen, char *port,
int portlen, int flags, char *errbuf, int errbuflen)
{
struct sockaddr_storage mysockaddr;
socklen_t sockaddrlen;
sockaddrlen = sizeof(struct sockaddr_storage);
if (getsockname(sock, (struct sockaddr *) &mysockaddr, &sockaddrlen) == -1)
{
sock_geterrmsg(errbuf, errbuflen, "getsockname() failed");
return 0;
}
/* Returns the numeric address of the host that triggered the error */
return sock_getascii_addrport(&mysockaddr, address, addrlen, port, portlen, flags, errbuf, errbuflen);
}
/*
* \brief It retrieves two strings containing the address and the port of a given 'sockaddr' variable.
*
* This function is basically an extended version of the inet_ntop(), which does not exist in
* Winsock because the same result can be obtained by using the getnameinfo().
* However, differently from inet_ntop(), this function is able to return also literal names
* (e.g. 'localhost') dependently from the 'Flags' parameter.
*
* The function accepts a sockaddr_storage variable (which can be returned by several functions
* like bind(), connect(), accept(), and more) and it transforms its content into a 'human'
* form. So, for instance, it is able to translate an hex address (stored in binary form) into
* a standard IPv6 address like "::1".
*
* The behavior of this function depends on the parameters we have in the 'Flags' variable, which
* are the ones allowed in the standard getnameinfo() socket function.
*
* \param sockaddr: a 'sockaddr_in' or 'sockaddr_in6' structure containing the address that
* need to be translated from network form into the presentation form. This structure must be
* zero-ed prior using it, and the address family field must be filled with the proper value.
* The user must cast any 'sockaddr_in' or 'sockaddr_in6' structures to 'sockaddr_storage' before
* calling this function.
*
* \param address: it contains the address that will be returned by the function. This buffer
* must be properly allocated by the user. The address can be either literal or numeric depending
* on the value of 'Flags'.
*
* \param addrlen: the length of the 'address' buffer.
*
* \param port: it contains the port that will be returned by the function. This buffer
* must be properly allocated by the user.
*
* \param portlen: the length of the 'port' buffer.
*
* \param flags: a set of flags (the ones defined into the getnameinfo() standard socket function)
* that determine if the resulting address must be in numeric / literal form, and so on.
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return It returns '-1' if this function succeeds, '0' otherwise.
* The address and port corresponding to the given SockAddr are returned back in the buffers 'address'
* and 'port'.
* In any case, the returned strings are '0' terminated.
*/
int sock_getascii_addrport(const struct sockaddr_storage *sockaddr, char *address, int addrlen, char *port, int portlen, int flags, char *errbuf, size_t errbuflen)
{
socklen_t sockaddrlen;
int retval; /* Variable that keeps the return value; */
retval = -1;
#ifdef _WIN32
if (sockaddr->ss_family == AF_INET)
sockaddrlen = sizeof(struct sockaddr_in);
else
sockaddrlen = sizeof(struct sockaddr_in6);
#else
sockaddrlen = sizeof(struct sockaddr_storage);
#endif
if ((flags & NI_NUMERICHOST) == 0) /* Check that we want literal names */
{
if ((sockaddr->ss_family == AF_INET6) &&
(memcmp(&((const 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))
{
if (address)
pcapint_strlcpy(address, SOCKET_NAME_NULL_DAD, addrlen);
return retval;
}
}
if (getnameinfo((const struct sockaddr *) sockaddr, sockaddrlen, address, addrlen, port, portlen, flags) != 0)
{
/* If the user wants to receive an error message */
if (errbuf)
{
sock_geterrmsg(errbuf, errbuflen,
"getnameinfo() failed");
errbuf[errbuflen - 1] = 0;
}
if (address)
{
pcapint_strlcpy(address, SOCKET_NO_NAME_AVAILABLE, addrlen);
address[addrlen - 1] = 0;
}
if (port)
{
pcapint_strlcpy(port, SOCKET_NO_PORT_AVAILABLE, portlen);
port[portlen - 1] = 0;
}
retval = 0;
}
return retval;
}
/*
* \brief It translates an address from the 'presentation' form into the 'network' form.
*
* This function basically replaces inet_pton(), which does not exist in Winsock because
* the same result can be obtained by using the getaddrinfo().
* An additional advantage is that 'Address' can be both a numeric address (e.g. '127.0.0.1',
* like in inet_pton() ) and a literal name (e.g. 'localhost').
*
* This function does the reverse job of sock_getascii_addrport().
*
* \param address: a zero-terminated string which contains the name you have to
* translate. The name can be either literal (e.g. 'localhost') or numeric (e.g. '::1').
*
* \param sockaddr: a user-allocated sockaddr_storage structure which will contains the
* 'network' form of the requested address.
*
* \param addr_family: a constant which can assume the following values:
* - 'AF_INET' if we want to ping an IPv4 host
* - 'AF_INET6' if we want to ping an IPv6 host
* - 'AF_UNSPEC' if we do not have preferences about the protocol used to ping the host
*
* \param errbuf: a pointer to an user-allocated buffer that will contain the complete
* error message. This buffer has to be at least 'errbuflen' in length.
* It can be NULL; in this case the error cannot be printed.
*
* \param errbuflen: length of the buffer that will contains the error. The error message cannot be
* larger than 'errbuflen - 1' because the last char is reserved for the string terminator.
*
* \return '-1' if the translation succeeded, '-2' if there was some non critical error, '0'
* otherwise. In case it fails, the content of the SockAddr variable remains unchanged.
* A 'non critical error' can occur in case the 'Address' is a literal name, which can be mapped
* to several network addresses (e.g. 'foo.bar.com' => '10.2.2.2' and '10.2.2.3'). In this case
* the content of the SockAddr parameter will be the address corresponding to the first mapping.
*
* \warning The sockaddr_storage structure MUST be allocated by the user.
*/
int sock_present2network(const char *address, struct sockaddr_storage *sockaddr, int addr_family, char *errbuf, int errbuflen)
{
struct addrinfo *addrinfo;
struct addrinfo hints;
memset(&hints, 0, sizeof(hints));
hints.ai_family = addr_family;
addrinfo = sock_initaddress(address, "22222" /* fake port */, &hints,
errbuf, errbuflen);
if (addrinfo == NULL)
return 0;
if (addrinfo->ai_family == PF_INET)
memcpy(sockaddr, addrinfo->ai_addr, sizeof(struct sockaddr_in));
else
memcpy(sockaddr, addrinfo->ai_addr, sizeof(struct sockaddr_in6));
if (addrinfo->ai_next != NULL)
{
freeaddrinfo(addrinfo);
if (errbuf)
snprintf(errbuf, errbuflen, "More than one socket requested; using the first one returned");
return -2;
}
freeaddrinfo(addrinfo);
return -1;
}
