152 lines · c
1// SPDX-License-Identifier: GPL-2.02 3#include <arpa/inet.h>4#include <errno.h>5#include <error.h>6#include <netinet/in.h>7#include <netinet/tcp.h>8#include <signal.h>9#include <stdio.h>10#include <stdlib.h>11#include <sys/socket.h>12#include <sys/time.h>13#include <unistd.h>14 15static int child_pid;16 17static unsigned long timediff(struct timeval s, struct timeval e)18{19 unsigned long s_us, e_us;20 21 s_us = s.tv_sec * 1000000 + s.tv_usec;22 e_us = e.tv_sec * 1000000 + e.tv_usec;23 if (s_us > e_us)24 return 0;25 return e_us - s_us;26}27 28static void client(int port)29{30 int sock = 0;31 struct sockaddr_in addr, laddr;32 socklen_t len = sizeof(laddr);33 struct linger sl;34 int flag = 1;35 int buffer;36 struct timeval start, end;37 unsigned long lat, sum_lat = 0, nr_lat = 0;38 39 while (1) {40 gettimeofday(&start, NULL);41 42 sock = socket(AF_INET, SOCK_STREAM, 0);43 if (sock < 0)44 error(-1, errno, "socket creation");45 46 sl.l_onoff = 1;47 sl.l_linger = 0;48 if (setsockopt(sock, SOL_SOCKET, SO_LINGER, &sl, sizeof(sl)))49 error(-1, errno, "setsockopt(linger)");50 51 if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY,52 &flag, sizeof(flag)))53 error(-1, errno, "setsockopt(nodelay)");54 55 addr.sin_family = AF_INET;56 addr.sin_port = htons(port);57 58 if (inet_pton(AF_INET, "127.0.0.1", &addr.sin_addr) <= 0)59 error(-1, errno, "inet_pton");60 61 if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0)62 error(-1, errno, "connect");63 64 send(sock, &buffer, sizeof(buffer), 0);65 if (read(sock, &buffer, sizeof(buffer)) == -1)66 error(-1, errno, "waiting read");67 68 gettimeofday(&end, NULL);69 lat = timediff(start, end);70 sum_lat += lat;71 nr_lat++;72 if (lat < 100000)73 goto close;74 75 if (getsockname(sock, (struct sockaddr *)&laddr, &len) == -1)76 error(-1, errno, "getsockname");77 printf("port: %d, lat: %lu, avg: %lu, nr: %lu\n",78 ntohs(laddr.sin_port), lat,79 sum_lat / nr_lat, nr_lat);80close:81 fflush(stdout);82 close(sock);83 }84}85 86static void server(int sock, struct sockaddr_in address)87{88 int accepted;89 int addrlen = sizeof(address);90 int buffer;91 92 while (1) {93 accepted = accept(sock, (struct sockaddr *)&address,94 (socklen_t *)&addrlen);95 if (accepted < 0)96 error(-1, errno, "accept");97 98 if (read(accepted, &buffer, sizeof(buffer)) == -1)99 error(-1, errno, "read");100 close(accepted);101 }102}103 104static void sig_handler(int signum)105{106 kill(SIGTERM, child_pid);107 exit(0);108}109 110int main(int argc, char const *argv[])111{112 int sock;113 int opt = 1;114 struct sockaddr_in address;115 struct sockaddr_in laddr;116 socklen_t len = sizeof(laddr);117 118 if (signal(SIGTERM, sig_handler) == SIG_ERR)119 error(-1, errno, "signal");120 121 sock = socket(AF_INET, SOCK_STREAM, 0);122 if (sock < 0)123 error(-1, errno, "socket");124 125 if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT,126 &opt, sizeof(opt)) == -1)127 error(-1, errno, "setsockopt");128 129 address.sin_family = AF_INET;130 address.sin_addr.s_addr = INADDR_ANY;131 /* dynamically allocate unused port */132 address.sin_port = 0;133 134 if (bind(sock, (struct sockaddr *)&address, sizeof(address)) < 0)135 error(-1, errno, "bind");136 137 if (listen(sock, 3) < 0)138 error(-1, errno, "listen");139 140 if (getsockname(sock, (struct sockaddr *)&laddr, &len) == -1)141 error(-1, errno, "getsockname");142 143 fprintf(stderr, "server port: %d\n", ntohs(laddr.sin_port));144 child_pid = fork();145 if (!child_pid)146 client(ntohs(laddr.sin_port));147 else148 server(sock, laddr);149 150 return 0;151}152