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 fucntions 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, const char *port, int proto )
00137 {
00138     int ret;
00139     struct addrinfo hints, *addr_list, *cur;
00140 
00141     if( ( ret = net_prepare() ) != 0 )
00142         return( ret );
00143 
00144     /* Do name resolution with both IPv6 and IPv4 */
00145     memset( &hints, 0, sizeof( hints ) );
00146     hints.ai_family = AF_UNSPEC;
00147     hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
00148     hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;
00149 
00150     if( getaddrinfo( host, port, &hints, &addr_list ) != 0 )
00151         return( MBEDTLS_ERR_NET_UNKNOWN_HOST );
00152 
00153     /* Try the sockaddrs until a connection succeeds */
00154     ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
00155     for( cur = addr_list; cur != NULL; cur = cur->ai_next )
00156     {
00157         ctx->fd = (int) socket( cur->ai_family, cur->ai_socktype,
00158                             cur->ai_protocol );
00159         if( ctx->fd < 0 )
00160         {
00161             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
00162             continue;
00163         }
00164 
00165         if( connect( ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen ) == 0 )
00166         {
00167             ret = 0;
00168             break;
00169         }
00170 
00171         close( ctx->fd );
00172         ret = MBEDTLS_ERR_NET_CONNECT_FAILED;
00173     }
00174 
00175     freeaddrinfo( addr_list );
00176 
00177     return( ret );
00178 }
00179 
00180 /*
00181  * Create a listening socket on bind_ip:port
00182  */
00183 int mbedtls_net_bind( mbedtls_net_context *ctx, const char *bind_ip, const char *port, int proto )
00184 {
00185     int n, ret;
00186     struct addrinfo hints, *addr_list, *cur;
00187 
00188     if( ( ret = net_prepare() ) != 0 )
00189         return( ret );
00190 
00191     /* Bind to IPv6 and/or IPv4, but only in the desired protocol */
00192     memset( &hints, 0, sizeof( hints ) );
00193     hints.ai_family = AF_UNSPEC;
00194     hints.ai_socktype = proto == MBEDTLS_NET_PROTO_UDP ? SOCK_DGRAM : SOCK_STREAM;
00195     hints.ai_protocol = proto == MBEDTLS_NET_PROTO_UDP ? IPPROTO_UDP : IPPROTO_TCP;
00196     if( bind_ip == NULL )
00197         hints.ai_flags = AI_PASSIVE;
00198 
00199     if( getaddrinfo( bind_ip, port, &hints, &addr_list ) != 0 )
00200         return( MBEDTLS_ERR_NET_UNKNOWN_HOST );
00201 
00202     /* Try the sockaddrs until a binding succeeds */
00203     ret = MBEDTLS_ERR_NET_UNKNOWN_HOST;
00204     for( cur = addr_list; cur != NULL; cur = cur->ai_next )
00205     {
00206         ctx->fd = (int) socket( cur->ai_family, cur->ai_socktype,
00207                             cur->ai_protocol );
00208         if( ctx->fd < 0 )
00209         {
00210             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
00211             continue;
00212         }
00213 
00214         n = 1;
00215         if( setsockopt( ctx->fd, SOL_SOCKET, SO_REUSEADDR,
00216                         (const char *) &n, sizeof( n ) ) != 0 )
00217         {
00218             close( ctx->fd );
00219             ret = MBEDTLS_ERR_NET_SOCKET_FAILED;
00220             continue;
00221         }
00222 
00223         if( bind( ctx->fd, cur->ai_addr, MSVC_INT_CAST cur->ai_addrlen ) != 0 )
00224         {
00225             close( ctx->fd );
00226             ret = MBEDTLS_ERR_NET_BIND_FAILED;
00227             continue;
00228         }
00229 
00230         /* Listen only makes sense for TCP */
00231         if( proto == MBEDTLS_NET_PROTO_TCP )
00232         {
00233             if( listen( ctx->fd, MBEDTLS_NET_LISTEN_BACKLOG ) != 0 )
00234             {
00235                 close( ctx->fd );
00236                 ret = MBEDTLS_ERR_NET_LISTEN_FAILED;
00237                 continue;
00238             }
00239         }
00240 
00241         /* I we ever get there, it's a success */
00242         ret = 0;
00243         break;
00244     }
00245 
00246     freeaddrinfo( addr_list );
00247 
00248     return( ret );
00249 
00250 }
00251 
00252 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00253     !defined(EFI32)
00254 /*
00255  * Check if the requested operation would be blocking on a non-blocking socket
00256  * and thus 'failed' with a negative return value.
00257  */
00258 static int net_would_block( const mbedtls_net_context *ctx )
00259 {
00260     ((void) ctx);
00261     return( WSAGetLastError() == WSAEWOULDBLOCK );
00262 }
00263 #else
00264 /*
00265  * Check if the requested operation would be blocking on a non-blocking socket
00266  * and thus 'failed' with a negative return value.
00267  *
00268  * Note: on a blocking socket this function always returns 0!
00269  */
00270 static int net_would_block( const mbedtls_net_context *ctx )
00271 {
00272     /*
00273      * Never return 'WOULD BLOCK' on a non-blocking socket
00274      */
00275     if( ( fcntl( ctx->fd, F_GETFL ) & O_NONBLOCK ) != O_NONBLOCK )
00276         return( 0 );
00277 
00278     switch( errno )
00279     {
00280 #if defined EAGAIN
00281         case EAGAIN:
00282 #endif
00283 #if defined EWOULDBLOCK && EWOULDBLOCK != EAGAIN
00284         case EWOULDBLOCK:
00285 #endif
00286             return( 1 );
00287     }
00288     return( 0 );
00289 }
00290 #endif /* ( _WIN32 || _WIN32_WCE ) && !EFIX64 && !EFI32 */
00291 
00292 /*
00293  * Accept a connection from a remote client
00294  */
00295 int mbedtls_net_accept( mbedtls_net_context *bind_ctx,
00296                         mbedtls_net_context *client_ctx,
00297                         void *client_ip, size_t buf_size, size_t *ip_len )
00298 {
00299     int ret;
00300     int type;
00301 
00302     struct sockaddr_storage client_addr;
00303 
00304 #if defined(__socklen_t_defined) || defined(_SOCKLEN_T) ||  \
00305     defined(_SOCKLEN_T_DECLARED) || defined(__DEFINED_socklen_t)
00306     socklen_t n = (socklen_t) sizeof( client_addr );
00307     socklen_t type_len = (socklen_t) sizeof( type );
00308 #else
00309     int n = (int) sizeof( client_addr );
00310     int type_len = (int) sizeof( type );
00311 #endif
00312 
00313     /* Is this a TCP or UDP socket? */
00314     if( getsockopt( bind_ctx->fd, SOL_SOCKET, SO_TYPE,
00315                     (void *) &type, &type_len ) != 0 ||
00316         ( type != SOCK_STREAM && type != SOCK_DGRAM ) )
00317     {
00318         return( MBEDTLS_ERR_NET_ACCEPT_FAILED );
00319     }
00320 
00321     if( type == SOCK_STREAM )
00322     {
00323         /* TCP: actual accept() */
00324         ret = client_ctx->fd = (int) accept( bind_ctx->fd,
00325                                          (struct sockaddr *) &client_addr, &n );
00326     }
00327     else
00328     {
00329         /* UDP: wait for a message, but keep it in the queue */
00330         char buf[1] = { 0 };
00331 
00332         ret = (int) recvfrom( bind_ctx->fd, buf, sizeof( buf ), MSG_PEEK,
00333                         (struct sockaddr *) &client_addr, &n );
00334 
00335 #if defined(_WIN32)
00336         if( ret == SOCKET_ERROR &&
00337             WSAGetLastError() == WSAEMSGSIZE )
00338         {
00339             /* We know buf is too small, thanks, just peeking here */
00340             ret = 0;
00341         }
00342 #endif
00343     }
00344 
00345     if( ret < 0 )
00346     {
00347         if( net_would_block( bind_ctx ) != 0 )
00348             return( MBEDTLS_ERR_SSL_WANT_READ );
00349 
00350         return( MBEDTLS_ERR_NET_ACCEPT_FAILED );
00351     }
00352 
00353     /* UDP: hijack the listening socket to communicate with the client,
00354      * then bind a new socket to accept new connections */
00355     if( type != SOCK_STREAM )
00356     {
00357         struct sockaddr_storage local_addr;
00358         int one = 1;
00359 
00360         if( connect( bind_ctx->fd, (struct sockaddr *) &client_addr, n ) != 0 )
00361             return( MBEDTLS_ERR_NET_ACCEPT_FAILED );
00362 
00363         client_ctx->fd = bind_ctx->fd;
00364         bind_ctx->fd   = -1; /* In case we exit early */
00365 
00366         n = sizeof( struct sockaddr_storage );
00367         if( getsockname( client_ctx->fd,
00368                          (struct sockaddr *) &local_addr, &n ) != 0 ||
00369             ( bind_ctx->fd = (int) socket( local_addr.ss_family,
00370                                            SOCK_DGRAM, IPPROTO_UDP ) ) < 0 ||
00371             setsockopt( bind_ctx->fd, SOL_SOCKET, SO_REUSEADDR,
00372                         (const char *) &one, sizeof( one ) ) != 0 )
00373         {
00374             return( MBEDTLS_ERR_NET_SOCKET_FAILED );
00375         }
00376 
00377         if( bind( bind_ctx->fd, (struct sockaddr *) &local_addr, n ) != 0 )
00378         {
00379             return( MBEDTLS_ERR_NET_BIND_FAILED );
00380         }
00381     }
00382 
00383     if( client_ip != NULL )
00384     {
00385         if( client_addr.ss_family == AF_INET )
00386         {
00387             struct sockaddr_in *addr4 = (struct sockaddr_in *) &client_addr;
00388             *ip_len = sizeof( addr4->sin_addr.s_addr );
00389 
00390             if( buf_size < *ip_len )
00391                 return( MBEDTLS_ERR_NET_BUFFER_TOO_SMALL );
00392 
00393             memcpy( client_ip, &addr4->sin_addr.s_addr, *ip_len );
00394         }
00395         else
00396         {
00397             struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) &client_addr;
00398             *ip_len = sizeof( addr6->sin6_addr.s6_addr );
00399 
00400             if( buf_size < *ip_len )
00401                 return( MBEDTLS_ERR_NET_BUFFER_TOO_SMALL );
00402 
00403             memcpy( client_ip, &addr6->sin6_addr.s6_addr, *ip_len);
00404         }
00405     }
00406 
00407     return( 0 );
00408 }
00409 
00410 /*
00411  * Set the socket blocking or non-blocking
00412  */
00413 int mbedtls_net_set_block( mbedtls_net_context *ctx )
00414 {
00415 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00416     !defined(EFI32)
00417     u_long n = 0;
00418     return( ioctlsocket( ctx->fd, FIONBIO, &n ) );
00419 #else
00420     return( fcntl( ctx->fd, F_SETFL, fcntl( ctx->fd, F_GETFL ) & ~O_NONBLOCK ) );
00421 #endif
00422 }
00423 
00424 int mbedtls_net_set_nonblock( mbedtls_net_context *ctx )
00425 {
00426 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00427     !defined(EFI32)
00428     u_long n = 1;
00429     return( ioctlsocket( ctx->fd, FIONBIO, &n ) );
00430 #else
00431     return( fcntl( ctx->fd, F_SETFL, fcntl( ctx->fd, F_GETFL ) | O_NONBLOCK ) );
00432 #endif
00433 }
00434 
00435 /*
00436  * Portable usleep helper
00437  */
00438 void mbedtls_net_usleep( unsigned long usec )
00439 {
00440 #if defined(_WIN32)
00441     Sleep( ( usec + 999 ) / 1000 );
00442 #else
00443     struct timeval tv;
00444     tv.tv_sec  = usec / 1000000;
00445 #if defined(__unix__) || defined(__unix) || \
00446     ( defined(__APPLE__) && defined(__MACH__) )
00447     tv.tv_usec = (suseconds_t) usec % 1000000;
00448 #else
00449     tv.tv_usec = usec % 1000000;
00450 #endif
00451     select( 0, NULL, NULL, NULL, &tv );
00452 #endif
00453 }
00454 
00455 /*
00456  * Read at most 'len' characters
00457  */
00458 int mbedtls_net_recv( void *ctx, unsigned char *buf, size_t len )
00459 {
00460     int ret;
00461     int fd = ((mbedtls_net_context *) ctx)->fd;
00462 
00463     if( fd < 0 )
00464         return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
00465 
00466     ret = (int) read( fd, buf, len );
00467 
00468     if( ret < 0 )
00469     {
00470         if( net_would_block( ctx ) != 0 )
00471             return( MBEDTLS_ERR_SSL_WANT_READ );
00472 
00473 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00474     !defined(EFI32)
00475         if( WSAGetLastError() == WSAECONNRESET )
00476             return( MBEDTLS_ERR_NET_CONN_RESET );
00477 #else
00478         if( errno == EPIPE || errno == ECONNRESET )
00479             return( MBEDTLS_ERR_NET_CONN_RESET );
00480 
00481         if( errno == EINTR )
00482             return( MBEDTLS_ERR_SSL_WANT_READ );
00483 #endif
00484 
00485         return( MBEDTLS_ERR_NET_RECV_FAILED );
00486     }
00487 
00488     return( ret );
00489 }
00490 
00491 /*
00492  * Read at most 'len' characters, blocking for at most 'timeout' ms
00493  */
00494 int mbedtls_net_recv_timeout( void *ctx, unsigned char *buf, size_t len,
00495                       uint32_t timeout )
00496 {
00497     int ret;
00498     struct timeval tv;
00499     fd_set read_fds;
00500     int fd = ((mbedtls_net_context *) ctx)->fd;
00501 
00502     if( fd < 0 )
00503         return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
00504 
00505     FD_ZERO( &read_fds );
00506     FD_SET( fd, &read_fds );
00507 
00508     tv.tv_sec  = timeout / 1000;
00509     tv.tv_usec = ( timeout % 1000 ) * 1000;
00510 
00511     ret = select( fd + 1, &read_fds, NULL, NULL, timeout == 0 ? NULL : &tv );
00512 
00513     /* Zero fds ready means we timed out */
00514     if( ret == 0 )
00515         return( MBEDTLS_ERR_SSL_TIMEOUT );
00516 
00517     if( ret < 0 )
00518     {
00519 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00520     !defined(EFI32)
00521         if( WSAGetLastError() == WSAEINTR )
00522             return( MBEDTLS_ERR_SSL_WANT_READ );
00523 #else
00524         if( errno == EINTR )
00525             return( MBEDTLS_ERR_SSL_WANT_READ );
00526 #endif
00527 
00528         return( MBEDTLS_ERR_NET_RECV_FAILED );
00529     }
00530 
00531     /* This call will not block */
00532     return( mbedtls_net_recv( ctx, buf, len ) );
00533 }
00534 
00535 /*
00536  * Write at most 'len' characters
00537  */
00538 int mbedtls_net_send( void *ctx, const unsigned char *buf, size_t len )
00539 {
00540     int ret;
00541     int fd = ((mbedtls_net_context *) ctx)->fd;
00542 
00543     if( fd < 0 )
00544         return( MBEDTLS_ERR_NET_INVALID_CONTEXT );
00545 
00546     ret = (int) write( fd, buf, len );
00547 
00548     if( ret < 0 )
00549     {
00550         if( net_would_block( ctx ) != 0 )
00551             return( MBEDTLS_ERR_SSL_WANT_WRITE );
00552 
00553 #if ( defined(_WIN32) || defined(_WIN32_WCE) ) && !defined(EFIX64) && \
00554     !defined(EFI32)
00555         if( WSAGetLastError() == WSAECONNRESET )
00556             return( MBEDTLS_ERR_NET_CONN_RESET );
00557 #else
00558         if( errno == EPIPE || errno == ECONNRESET )
00559             return( MBEDTLS_ERR_NET_CONN_RESET );
00560 
00561         if( errno == EINTR )
00562             return( MBEDTLS_ERR_SSL_WANT_WRITE );
00563 #endif
00564 
00565         return( MBEDTLS_ERR_NET_SEND_FAILED );
00566     }
00567 
00568     return( ret );
00569 }
00570 
00571 /*
00572  * Gracefully close the connection
00573  */
00574 void mbedtls_net_free( mbedtls_net_context *ctx )
00575 {
00576     if( ctx->fd == -1 )
00577         return;
00578 
00579     shutdown( ctx->fd, 2 );
00580     close( ctx->fd );
00581 
00582     ctx->fd = -1;
00583 }
00584 
00585 #endif /* MBEDTLS_NET_C */