| 1 | // Simple sink program that opens a tcp socket on a random port
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| 2 | // and then reads everything the socket has to write and then ends.
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| 3 | 
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| 4 | #define _GNU_SOURCE
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| 5 | 
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| 6 | #include <stdint.h>
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| 7 | #include <stdio.h>
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| 8 | #include <stdlib.h>
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| 9 | #include <string.h>
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| 10 | 
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| 11 | #include <errno.h>
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| 12 | #include <time.h>
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| 13 | #include <unistd.h>
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| 14 | 
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| 15 | #include <sys/socket.h>
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| 16 | #include <netinet/in.h>
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| 17 | 
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| 18 | enum {
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| 19 |         USAGE_ERROR = 1,
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| 20 |         SOCKET_ERROR,
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| 21 |         BIND_INUSE,
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| 22 |         BIND_ERROR,
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| 23 |         GETNAME_ERROR,
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| 24 |         LISTEN_ERROR,
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| 25 |         ACCEPT_ERROR,
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| 26 |         READ_ERROR
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| 27 | };
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| 28 | 
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| 29 | enum { buffer_len = 10240 };
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| 30 | char buffer[buffer_len];
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| 31 | 
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| 32 | enum { TIMEGRAN = 1000000000LL };
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| 33 | 
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| 34 | int main(int argc, char * argv[]) {
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| 35 |         int port = 0;
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| 36 |         switch(argc) {
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| 37 |         case 1: break;
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| 38 |         case 2:
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| 39 |                 {
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| 40 |                         const char * const str = argv[1];
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| 41 |                         char* endptr;
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| 42 |                         unsigned long long ret = strtoul(str, &endptr, 10);
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| 43 |                         if('\0' != *endptr) { fprintf( stderr, "Invalid argument \"%s\" (not a number)\n", str ); goto USAGE;}
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| 44 |                         if(errno == ERANGE || ret > 65535)  { fprintf( stderr, "Invalid argument \"%s\" (value too large)\n", str ); goto USAGE;}
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| 45 | 
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| 46 |                         port = ret;
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| 47 |                         break;
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| 48 |                 }
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| 49 |         USAGE:
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| 50 |         default:
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| 51 |                 fprintf( stderr, "USAGE: %s [port]\n", argv[0] );
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| 52 |                 exit( USAGE_ERROR );
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| 53 |         }
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| 54 | 
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| 55 |         printf( "%d: Listening on port %d\n", getpid(), port );
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| 56 |         int listenfd = socket(AF_INET, SOCK_STREAM, 0);
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| 57 |         if(listenfd < 0) {
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| 58 |                 fprintf( stderr, "socket error: (%d) %s\n", (int)errno, strerror(errno) );
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| 59 |                 exit( SOCKET_ERROR );
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| 60 |         }
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| 61 | 
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| 62 |         int ret = 0;
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| 63 |         struct sockaddr_in address;
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| 64 |         socklen_t addrlen = sizeof(address);
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| 65 |         memset( (char *)&address, '\0', addrlen );
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| 66 |         address.sin_family = AF_INET;
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| 67 |         address.sin_addr.s_addr = htonl( INADDR_ANY );
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| 68 |         address.sin_port = htons( port );
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| 69 | 
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| 70 |         ret = bind( listenfd, (struct sockaddr *) &address, addrlen );
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| 71 |         if(ret < 0) {
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| 72 |                 if(errno == EADDRINUSE) {
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| 73 |                         fprintf( stderr, "Port already in use in non-interactive mode. Aborting\n" );
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| 74 |                         exit( BIND_INUSE );
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| 75 |                 }
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| 76 |                 fprintf( stderr, "bind error: (%d) %s\n", (int)errno, strerror(errno) );
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| 77 |                 exit( BIND_ERROR );
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| 78 |         }
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| 79 | 
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| 80 |         ret = getsockname( listenfd, (struct sockaddr *) &address, &addrlen );
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| 81 |         if(ret < 0) {
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| 82 |                 fprintf( stderr, "getname error: (%d) %s\n", (int)errno, strerror(errno) );
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| 83 |                 exit(GETNAME_ERROR);
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| 84 |         }
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| 85 | 
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| 86 |         printf( "actial port: %d\n", ntohs(address.sin_port) );
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| 87 | 
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| 88 |         ret = listen( listenfd, 1 );
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| 89 |         if(ret < 0) {
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| 90 |                 fprintf( stderr, "listen error: (%d) %s\n", (int)errno, strerror(errno) );
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| 91 |                 exit( 5 );
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| 92 |         }
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| 93 | 
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| 94 |         for(;;) {
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| 95 |                 struct sockaddr_in cli_addr;
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| 96 |                 __socklen_t clilen = sizeof(cli_addr);
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| 97 |                 int fd = accept( listenfd, (struct sockaddr *) &cli_addr, &clilen );
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| 98 |                 if(fd < 0) {
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| 99 |                         fprintf( stderr, "accept error: (%d) %s\n", (int)errno, strerror(errno) );
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| 100 |                         exit( ACCEPT_ERROR );
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| 101 |                 }
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| 102 | 
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| 103 |                 int error = 0;
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| 104 |                 size_t calls = 0;
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| 105 |                 size_t bytes = 0;
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| 106 | 
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| 107 |                 struct timespec after, before;
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| 108 | 
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| 109 |                 clock_gettime(CLOCK_MONOTONIC, &before);
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| 110 | 
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| 111 |                 for(;;) {
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| 112 |                         ret = recv(fd, buffer, buffer_len, 0);
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| 113 |                         if(ret == 0 ) goto EXIT;
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| 114 |                         if(ret < 0 ) {
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| 115 |                                 if( errno == EAGAIN || errno == EWOULDBLOCK) continue;
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| 116 |                                 if( errno == ECONNRESET ) { printf("Connection reset\n"); goto EXIT; }
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| 117 |                                 if( errno == EPIPE ) { printf("Pipe closed\n"); goto EXIT; }
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| 118 |                                 fprintf( stderr, "accept error: (%d) %s\n", (int)errno, strerror(errno) );
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| 119 |                                 error = READ_ERROR;
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| 120 |                                 goto EXIT;
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| 121 |                         }
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| 122 |                         calls++;
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| 123 |                         bytes += ret;
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| 124 |                 }
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| 125 |                 EXIT:;
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| 126 | 
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| 127 |                 clock_gettime(CLOCK_MONOTONIC, &after);
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| 128 | 
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| 129 |                 uint64_t tb = ((int64_t)before.tv_sec * TIMEGRAN) + before.tv_nsec;
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| 130 |                 uint64_t ta = ((int64_t)after.tv_sec * TIMEGRAN) + after.tv_nsec;
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| 131 |                 double secs = ((double)ta - tb) / TIMEGRAN;
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| 132 | 
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| 133 |                 printf("Received %'zu bytes in %'zu reads, %f seconds\n", bytes, calls, secs);
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| 134 |                 printf(" - %'3.3f bytes per second\n", (((double)bytes) / secs));
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| 135 |                 printf(" - %'3.3f bytes per calls\n", (((double)bytes) / calls));
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| 136 | 
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| 137 |                 close(fd);
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| 138 |                 if(error != 0) exit( error );
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| 139 |         }
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| 140 |         close(listenfd);
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| 141 |         return 0;
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| 142 | }
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