91 lines
2 KiB
C
91 lines
2 KiB
C
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#include <netdb.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/socket.h>
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#include <sys/types.h>
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#include <unistd.h>
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#define PORT "1025"
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#define HOST "localhost"
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#define SOURCE_PORT "1026"
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int create_client_sock(char* port, char* host, char* source_port) {
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struct addrinfo hints = {
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.ai_family = AF_INET6,
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.ai_socktype = SOCK_STREAM,
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.ai_flags = AI_V4MAPPED,
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};
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struct addrinfo* res;
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int err = getaddrinfo(host, port, &hints, &res);
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if (err != 0) {
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fprintf(stderr, "%s\n", gai_strerror(err));
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_exit(1);
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}
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struct addrinfo *self;
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err = getaddrinfo(NULL, source_port, &hints, &self);
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if (err != 0) {
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fprintf(stderr, "%s\n", gai_strerror(err));
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_exit(1);
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}
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int sfd;
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struct addrinfo* cur = res;
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for (; cur != NULL; cur = cur->ai_next) {
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// socket
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sfd = socket(cur->ai_family, cur->ai_socktype, cur->ai_protocol);
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if (sfd == -1) {
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perror("socket");
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continue;
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}
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int val = 1;
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err = setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
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if (err == -1) {
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perror("setsockopt");
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close(sfd);
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continue;
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}
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// Bind
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err = bind(sfd, self->ai_addr, self->ai_addrlen);
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if (err == -1) {
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perror("bind");
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close(sfd);
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continue;
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}
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// Connect
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err = connect(sfd, res->ai_addr, res->ai_addrlen);
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if (err == -1) {
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perror("connect");
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close(sfd);
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continue;
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}
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break;
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}
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freeaddrinfo(res);
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freeaddrinfo(self);
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if (cur == NULL) {
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fprintf(stderr, "failed to connect to the server\n");
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_exit(1);
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}
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return sfd;
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}
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int main() {
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int cfd = create_client_sock(PORT, HOST, SOURCE_PORT);
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char* msg = "This is a test message!\n";
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write(cfd, msg, strlen(msg));
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printf("message send: \"%s\"\n", msg);
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close(cfd);
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}
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