net_sockets.c

00001 /*
00002  *  TCP/IP or UDP/IP networking functions
00003  *
00004  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
00005  *  SPDX-License-Identifier: Apache-2.0
00006  *
00007  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00008  *  not use this file except in compliance with the License.
00009  *  You may obtain a copy of the License at
00010  *
00011  *  http://www.apache.org/licenses/LICENSE-2.0
00012  *
00013  *  Unless required by applicable law or agreed to in writing, software
00014  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00015  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00016  *  See the License for the specific language governing permissions and
00017  *  limitations under the License.
00018  *
00019  *  This file is part of mbed TLS (https://tls.mbed.org)
00020  */
00021 
00022 #if !defined(MBEDTLS_CONFIG_FILE)
00023 #include "mbedtls/config.h"
00024 #else
00025 #include MBEDTLS_CONFIG_FILE
00026 #endif
00027 
00028 #if defined(MBEDTLS_NET_C)
00029 
00030 #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
00031     !defined(__APPLE__) && !defined(_WIN32)
00032 #error "This module only works on Unix and Windows, see MBEDTLS_NET_C in config.h"
00033 #endif
00034 
00035 #if defined(MBEDTLS_PLATFORM_C)
00036 #include "mbedtls/platform.h"
00037 #else
00038 #include <stdlib.h>
00039 #endif
00040 
00041 #include "mbedtls/net_sockets.h"
00042 
00043 #include <string.h>
00044 
00045 #if (defined(_WIN32) || defined(_WIN32_WCE)) && !defined(EFIX64) && \
00046     !defined(EFI32)
00047 
00048 #ifdef _WIN32_WINNT
00049 #undef _WIN32_WINNT
00050 #endif
00051 /* Enables getaddrinfo() & Co */
00052 #define _WIN32_WINNT 0x0501
00053 #include <ws2tcpip.h>
00054 
00055 #include <winsock2.h>
00056 #include <windows.h>
00057 
00058 #if defined(_MSC_VER)
00059 #if defined(_WIN32_WCE)
00060 #pragma comment( lib, "ws2.lib" )
00061 #else
00062 #pragma comment( lib, "ws2_32.lib" )
00063 #endif
00064 #endif /* _MSC_VER */
00065 
00066 #define read(fd,buf,len)        recv( fd, (char*)( buf ), (int)( len ), 0 )
00067 #define write(fd,buf,len)       send( fd, (char*)( buf ), (int)( len ), 0 )
00068 #define close(fd)               closesocket(fd)
00069 
00070 static int wsa_init_done = 0;
00071 
00072 #else /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
00073 
00074 #include <sys/types.h>
00075 #include <sys/socket.h>
00076 #include <netinet/in.h>
00077 #include <arpa/inet.h>
00078 #include <sys/time.h>
00079 #include <unistd.h>
00080 #include <signal.h>
00081 #include <fcntl.h>
00082 #include <netdb.h>
00083 #include <errno.h>
00084 
00085 #endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
00086 
00087 /* Some MS functions want int and MSVC warns if we pass size_t,
00088  * but the standard functions use socklen_t, so cast only for MSVC */
00089 #if defined(_MSC_VER)
00090 #define MSVC_INT_CAST   (int)
00091 #else
00092 #define MSVC_INT_CAST
00093 #endif
00094 
00095 #include <stdio.h>
00096 
00097 #include <time.h>
00098 
00099 #include <stdint.h>
00100 
00101 /*
00102  * Prepare for using the sockets interface
00103  */
00104 static int net_prepare( void )
00105 {
00106 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00107     !defined(EFI32)
00108     WSADATA wsaData;
00109 
00110     if( wsa_init_done == 0 )
00111     {
00112         if( WSAStartup( MAKEWORD(2,0), &wsaData ) != 0 )
00113             return( MBEDTLS_ERR_NET_SOCKET_FAILED );
00114 
00115         wsa_init_done = 1;
00116     }
00117 #else
00118 #if !defined(EFIX64) && !defined(EFI32)
00119     signal( SIGPIPE, SIG_IGN );
00120 #endif
00121 #endif
00122     return( 0 );
00123 }
00124 
00125 /*
00126  * Initialize a context
00127  */
00128 void mbedtls_net_init( mbedtls_net_context *ctx )
00129 {
00130     ctx->fd = -1;
00131 }
00132 
00133 /*
00134  * Initiate a TCP connection with host:port and the given protocol
00135  */
00136 int mbedtls_net_connect( mbedtls_net_context *ctx, const char *host,
00137                          const char *port, int proto )
00138 {
00139     int ret;
00140     struct addrinfo hints, *addr_list, *cur;
00141 
00142     if( ( ret = net_prepare() ) != 0 )
00143         return( ret );
00144 
00145     /* Do name resolution with both IPv6 and IPv4 */
00146     memset( &hints, 0, sizeof( hints ) );
00147     hints.ai_family = AF_UNSPEC;
00148     hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
00149     hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;
00150 
00151     if( getaddrinfo( host, port, &hints, &addr_list ) != 0 )
00152         return( MBEDTLS_ERR_NET_UNKNOWN_HOST );
00153 
00154     /* Try the sockaddrs until a connection succeeds */
00155     ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
00156     for( cur = addr_list; cur != NULL; cur = cur->ai_next )
00157     {
00158         ctx->fd = (int) socket( cur->ai_family, cur->ai_socktype,
00159                             cur->ai_protocol );
00160         if( ctx->fd < 0 )
00161         {
00162             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
00163             continue;
00164         }
00165 
00166         if( connect( ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen ) == 0 )
00167         {
00168             ret = 0;
00169             break;
00170         }
00171 
00172         close( ctx->fd );
00173         ret = MBEDTLS_ERR_NET_CONNECT_FAILED;
00174     }
00175 
00176     freeaddrinfo( addr_list );
00177 
00178     return( ret );
00179 }
00180 
00181 /*
00182  * Create a listening socket on bind_ip:port
00183  */
00184 int mbedtls_net_bind( mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto )
00185 {
00186     int n, ret;
00187     struct addrinfo hints, *addr_list, *cur;
00188 
00189     if( ( ret = net_prepare() ) != 0 )
00190         return( ret );
00191 
00192     /* Bind to IPv6 and/or IPv4, but only in the desired protocol */
00193     memset( &hints, 0, sizeof( hints ) );
00194     hints.ai_family = AF_UNSPEC;
00195     hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
00196     hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;
00197     if( bind_ip == NULL )
00198         hints.ai_flags = AI_PASSIVE;
00199 
00200     if( getaddrinfo( bind_ip, port, &hints, &addr_list ) != 0 )
00201         return( MBEDTLS_ERR_NET_UNKNOWN_HOST );
00202 
00203     /* Try the sockaddrs until a binding succeeds */
00204     ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
00205     for( cur = addr_list; cur != NULL; cur = cur->ai_next )
00206     {
00207         ctx->fd = (int) socket( cur->ai_family, cur->ai_socktype,
00208                             cur->ai_protocol );
00209         if( ctx->fd < 0 )
00210         {
00211             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
00212             continue;
00213         }
00214 
00215         n = 1;
00216         if( setsockopt( ctx->fd, SOL_SOCKET, SO_REUSEADDR,
00217                         (const char *) &n, sizeof( n ) ) != 0 )
00218         {
00219             close( ctx->fd );
00220             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
00221             continue;
00222         }
00223 
00224         if( bind( ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen ) != 0 )
00225         {
00226             close( ctx->fd );
00227             ret = MBEDTLS_ERR_NET_BIND_FAILED;
00228             continue;
00229         }
00230 
00231         /* Listen only makes sense for TCP */
00232         if( proto == MBEDTLS_NET_PROTO_TCP )
00233         {
00234             if( listen( ctx->fd, MBEDTLS_NET_LISTEN_BACKLOG ) != 0 )
00235             {
00236                 close( ctx->fd );
00237                 ret = MBEDTLS_ERR_NET_LISTEN_FAILED;
00238                 continue;
00239             }
00240         }
00241 
00242         /* Bind was successful */
00243         ret = 0;
00244         break;
00245     }
00246 
00247     freeaddrinfo( addr_list );
00248 
00249     return( ret );
00250 
00251 }
00252 
00253 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00254     !defined(EFI32)
00255 /*
00256  * Check if the requested operation would be blocking on a non-blocking socket
00257  * and thus 'failed' with a negative return value.
00258  */
00259 static int net_would_block( const mbedtls_net_context *ctx )
00260 {
00261     ((void) ctx);
00262     return( WSAGetLastError() == WSAEWOULDBLOCK );
00263 }
00264 #else
00265 /*
00266  * Check if the requested operation would be blocking on a non-blocking socket
00267  * and thus 'failed' with a negative return value.
00268  *
00269  * Note: on a blocking socket this function always returns 0!
00270  */
00271 static int net_would_block( const mbedtls_net_context *ctx )
00272 {
00273     int err = errno;
00274     
00275     /*
00276      * Never return 'WOULD BLOCK' on a non-blocking socket
00277      */
00278     if( ( fcntl( ctx->fd, F_GETFL ) & O_NONBLOCK ) != O_NONBLOCK )
00279     {
00280         errno = err;
00281         return( 0 );
00282     }
00283 
00284     switch( errno = err )
00285     {
00286 #if defined EAGAIN
00287         case EAGAIN:
00288 #endif
00289 #if defined EWOULDBLOCK && EWOULDBLOCK != EAGAIN
00290         case EWOULDBLOCK:
00291 #endif
00292             return( 1 );
00293     }
00294     return( 0 );
00295 }
00296 #endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
00297 
00298 /*
00299  * Accept a connection from a remote client
00300  */
00301 int mbedtls_net_accept( mbedtls_net_context *bind_ctx,
00302                         mbedtls_net_context *client_ctx,
00303                         void *client_ip, size_t buf_size, size_t *ip_len )
00304 {
00305     int ret;
00306     int type;
00307 
00308     struct sockaddr_storage client_addr;
00309 
00310 #if defined(__socklen_t_defined) || defined(_SOCKLEN_T) ||  \
00311     defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t)
00312     socklen_t n = (socklen_t) sizeof( client_addr );
00313     socklen_t type_len = (socklen_t) sizeof( type );
00314 #else
00315     int n = (int) sizeof( client_addr );
00316     int type_len = (int) sizeof( type );
00317 #endif
00318 
00319     /* Is this a TCP or UDP socket? */
00320     if( getsockopt( bind_ctx->fd, SOL_SOCKET, SO_TYPE,
00321                     (void *) &type, &type_len ) != 0 ||
00322         ( type != SOCK_STREAM && type != SOCK_DGRAM ) )
00323     {
00324         return( MBEDTLS_ERR_NET_ACCEPT_FAILED );
00325     }
00326 
00327     if( type == SOCK_STREAM )
00328     {
00329         /* TCP: actual accept() */
00330         ret = client_ctx->fd = (int) accept( bind_ctx->fd,
00331                                              (struct sockaddr *) &client_addr, &n );
00332     }
00333     else
00334     {
00335         /* UDP: wait for a message, but keep it in the queue */
00336         char buf[1] = { 0 };
00337 
00338         ret = (int) recvfrom( bind_ctx->fd, buf, sizeof( buf ), MSG_PEEK,
00339                         (struct sockaddr *) &client_addr, &n );
00340 
00341 #if defined(_WIN32)
00342         if( ret == SOCKET_ERROR &&
00343             WSAGetLastError() == WSAEMSGSIZE )
00344         {
00345             /* We know buf is too small, thanks, just peeking here */
00346             ret = 0;
00347         }
00348 #endif
00349     }
00350 
00351     if( ret < 0 )
00352     {
00353         if( net_would_block( bind_ctx ) != 0 )
00354             return( MBEDTLS_ERR_SSL_WANT_READ );
00355 
00356         return( MBEDTLS_ERR_NET_ACCEPT_FAILED );
00357     }
00358 
00359     /* UDP: hijack the listening socket to communicate with the client,
00360      * then bind a new socket to accept new connections */
00361     if( type != SOCK_STREAM )
00362     {
00363         struct sockaddr_storage local_addr;
00364         int one = 1;
00365 
00366         if( connect( bind_ctx->fd, (struct sockaddr *) &client_addr, n ) != 0 )
00367             return( MBEDTLS_ERR_NET_ACCEPT_FAILED );
00368 
00369         client_ctx->fd = bind_ctx->fd;
00370         bind_ctx->fd   = -1; /* In case we exit early */
00371 
00372         n = sizeof( struct sockaddr_storage );
00373         if( getsockname( client_ctx->fd,
00374                          (struct sockaddr *) &local_addr, &n ) != 0 ||
00375             ( bind_ctx->fd = (int) socket( local_addr.ss_family,
00376                                            SOCK_DGRAM, IPPROTO_UDP ) ) < 0 ||
00377             setsockopt( bind_ctx->fd, SOL_SOCKET, SO_REUSEADDR,
00378                         (const char *) &one, sizeof( one ) ) != 0 )
00379         {
00380             return( MBEDTLS_ERR_NET_SOCKET_FAILED );
00381         }
00382 
00383         if( bind( bind_ctx->fd, (struct sockaddr *) &local_addr, n ) != 0 )
00384         {
00385             return( MBEDTLS_ERR_NET_BIND_FAILED );
00386         }
00387     }
00388 
00389     if( client_ip != NULL )
00390     {
00391         if( client_addr.ss_family == AF_INET )
00392         {
00393             struct sockaddr_in *addr4 = (struct sockaddr_in *) &client_addr;
00394             *ip_len = sizeof( addr4->sin_addr.s_addr );
00395 
00396             if( buf_size < *ip_len )
00397                 return( MBEDTLS_ERR_NET_BUFFER_TOO_SMALL );
00398 
00399             memcpy( client_ip, &addr4->sin_addr.s_addr, *ip_len );
00400         }
00401         else
00402         {
00403             struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) &client_addr;
00404             *ip_len = sizeof( addr6->sin6_addr.s6_addr );
00405 
00406             if( buf_size < *ip_len )
00407                 return( MBEDTLS_ERR_NET_BUFFER_TOO_SMALL );
00408 
00409             memcpy( client_ip, &addr6->sin6_addr.s6_addr, *ip_len);
00410         }
00411     }
00412 
00413     return( 0 );
00414 }
00415 
00416 /*
00417  * Set the socket blocking or non-blocking
00418  */
00419 int mbedtls_net_set_block( mbedtls_net_context *ctx )
00420 {
00421 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00422     !defined(EFI32)
00423     u_long n = 0;
00424     return( ioctlsocket( ctx->fd, FIONBIO, &n ) );
00425 #else
00426     return( fcntl( ctx->fd, F_SETFL, fcntl( ctx->fd, F_GETFL ) & ~O_NONBLOCK ) );
00427 #endif
00428 }
00429 
00430 int mbedtls_net_set_nonblock( mbedtls_net_context *ctx )
00431 {
00432 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00433     !defined(EFI32)
00434     u_long n = 1;
00435     return( ioctlsocket( ctx->fd, FIONBIO, &n ) );
00436 #else
00437     return( fcntl( ctx->fd, F_SETFL, fcntl( ctx->fd, F_GETFL ) | O_NONBLOCK ) );
00438 #endif
00439 }
00440 
00441 /*
00442  * Portable usleep helper
00443  */
00444 void mbedtls_net_usleep( unsigned long usec )
00445 {
00446 #if defined(_WIN32)
00447     Sleep( ( usec + 999 ) / 1000 );
00448 #else
00449     struct timeval tv;
00450     tv.tv_sec  = usec / 1000000;
00451 #if defined(__unix__) || defined(__unix) || \
00452     ( defined(__APPLE__) && defined(__MACH__) )
00453     tv.tv_usec = (suseconds_t) usec % 1000000;
00454 #else
00455     tv.tv_usec = usec % 1000000;
00456 #endif
00457     select( 0, NULL, NULL, NULL, &tv );
00458 #endif
00459 }
00460 
00461 /*
00462  * Read at most 'len' characters
00463  */
00464 int mbedtls_net_recv( void *ctx, unsigned char *buf, size_t len )
00465 {
00466     int ret;
00467     int fd = ((mbedtls_net_context *) ctx)->fd;
00468 
00469     if( fd < 0 )
00470         return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
00471 
00472     ret = (int) read( fd, buf, len );
00473 
00474     if( ret < 0 )
00475     {
00476         if( net_would_block( ctx ) != 0 )
00477             return( MBEDTLS_ERR_SSL_WANT_READ );
00478 
00479 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00480     !defined(EFI32)
00481         if( WSAGetLastError() == WSAECONNRESET )
00482             return( MBEDTLS_ERR_NET_CONN_RESET );
00483 #else
00484         if( errno == EPIPE || errno == ECONNRESET )
00485             return( MBEDTLS_ERR_NET_CONN_RESET );
00486 
00487         if( errno == EINTR )
00488             return( MBEDTLS_ERR_SSL_WANT_READ );
00489 #endif
00490 
00491         return( MBEDTLS_ERR_NET_RECV_FAILED );
00492     }
00493 
00494     return( ret );
00495 }
00496 
00497 /*
00498  * Read at most 'len' characters, blocking for at most 'timeout' ms
00499  */
00500 int mbedtls_net_recv_timeout( void *ctx, unsigned char *buf, size_t len,
00501                       uint32_t timeout )
00502 {
00503     int ret;
00504     struct timeval tv;
00505     fd_set read_fds;
00506     int fd = ((mbedtls_net_context *) ctx)->fd;
00507 
00508     if( fd < 0 )
00509         return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
00510 
00511     FD_ZERO( &read_fds );
00512     FD_SET( fd, &read_fds );
00513 
00514     tv.tv_sec  = timeout / 1000;
00515     tv.tv_usec = ( timeout % 1000 ) * 1000;
00516 
00517     ret = select( fd + 1, &read_fds, NULL, NULL, timeout == 0 ? NULL : &tv );
00518 
00519     /* Zero fds ready means we timed out */
00520     if( ret == 0 )
00521         return( MBEDTLS_ERR_SSL_TIMEOUT );
00522 
00523     if( ret < 0 )
00524     {
00525 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00526     !defined(EFI32)
00527         if( WSAGetLastError() == WSAEINTR )
00528             return( MBEDTLS_ERR_SSL_WANT_READ );
00529 #else
00530         if( errno == EINTR )
00531             return( MBEDTLS_ERR_SSL_WANT_READ );
00532 #endif
00533 
00534         return( MBEDTLS_ERR_NET_RECV_FAILED );
00535     }
00536 
00537     /* This call will not block */
00538     return( mbedtls_net_recv( ctx, buf, len ) );
00539 }
00540 
00541 /*
00542  * Write at most 'len' characters
00543  */
00544 int mbedtls_net_send( void *ctx, const unsigned char *buf, size_t len )
00545 {
00546     int ret;
00547     int fd = ((mbedtls_net_context *) ctx)->fd;
00548 
00549     if( fd < 0 )
00550         return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
00551 
00552     ret = (int) write( fd, buf, len );
00553 
00554     if( ret < 0 )
00555     {
00556         if( net_would_block( ctx ) != 0 )
00557             return( MBEDTLS_ERR_SSL_WANT_WRITE );
00558 
00559 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00560     !defined(EFI32)
00561         if( WSAGetLastError() == WSAECONNRESET )
00562             return( MBEDTLS_ERR_NET_CONN_RESET );
00563 #else
00564         if( errno == EPIPE || errno == ECONNRESET )
00565             return( MBEDTLS_ERR_NET_CONN_RESET );
00566 
00567         if( errno == EINTR )
00568             return( MBEDTLS_ERR_SSL_WANT_WRITE );
00569 #endif
00570 
00571         return( MBEDTLS_ERR_NET_SEND_FAILED );
00572     }
00573 
00574     return( ret );
00575 }
00576 
00577 /*
00578  * Gracefully close the connection
00579  */
00580 void mbedtls_net_free( mbedtls_net_context *ctx )
00581 {
00582     if( ctx->fd == -1 )
00583         return;
00584 
00585     shutdown( ctx->fd, 2 );
00586     close( ctx->fd );
00587 
00588     ctx->fd = -1;
00589 }
00590 
00591 #endif /* MBEDTLS_NET_C */