116 lines
2.9 KiB
C
116 lines
2.9 KiB
C
#include "net_tools.h"
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// some code is inspired by https://github.com/millken/c-example/blob/master/epoll-example.c
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// (which seems to be copied from https://banu.com/blog/2/how-to-use-epoll-a-complete-example-in-c/epoll-example.c )
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int create_tcp_client(char* host, char* service) {
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int err, sock;
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struct addrinfo conf;
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struct addrinfo *result, *cursor;
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memset(&conf, 0, sizeof(struct addrinfo));
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conf.ai_family = AF_UNSPEC;
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conf.ai_socktype = SOCK_STREAM;
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conf.ai_flags = 0;
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conf.ai_protocol = 0;
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err = getaddrinfo(host, service, &conf, &result);
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if (err != 0) {
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fprintf(stderr, "Error with getaddrinfo()\n");
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exit(EXIT_FAILURE);
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}
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for (cursor = result; cursor != NULL; cursor = cursor->ai_next) {
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sock = socket(cursor->ai_family, cursor->ai_socktype, cursor->ai_protocol);
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if (sock == -1) continue;
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if (connect(sock, cursor->ai_addr, cursor->ai_addrlen) != -1) break;
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close(sock);
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}
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if (cursor == NULL) {
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fprintf(stderr, "No connect worked\n");
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exit(EXIT_FAILURE);
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}
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freeaddrinfo(result);
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return sock;
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}
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int create_tcp_server(char* service) {
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int err, sock;
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struct addrinfo conf;
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struct addrinfo *result, *cursor;
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memset(&conf, 0, sizeof(struct addrinfo));
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conf.ai_family = AF_UNSPEC;
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conf.ai_socktype = SOCK_STREAM;
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conf.ai_flags = AI_PASSIVE;
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conf.ai_protocol = 0;
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err = getaddrinfo(NULL, service, &conf, &result);
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if (err != 0) {
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fprintf(stderr, "Error with getaddrinfo()\n");
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exit(EXIT_FAILURE);
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}
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for (cursor = result; cursor != NULL; cursor = cursor->ai_next) {
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sock = socket(cursor->ai_family, cursor->ai_socktype, cursor->ai_protocol);
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if (sock == -1) continue;
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if (bind(sock, cursor->ai_addr, cursor->ai_addrlen) != -1) break;
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close(sock);
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}
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if (cursor == NULL) {
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fprintf(stderr, "We failed to bind\n");
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exit(EXIT_FAILURE);
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}
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freeaddrinfo (result);
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return sock;
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}
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/*
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* The idea is to get the file descriptor flags
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* then we add to the bitmask O_NONBLOCK and set the
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* new bitmask to the socket
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*/
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int make_socket_non_blocking(int fd) {
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int err, flags;
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flags = fcntl (fd, F_GETFL);
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if (flags == -1) {
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perror("Failed to get socket's flags via fcntl");
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return -1;
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}
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flags |= O_NONBLOCK;
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err = fcntl (fd, F_SETFL, flags);
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if (err != 0) {
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perror("Failed to set socket's flags via fcntl");
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return -1;
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}
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return 0;
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}
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int read_entity(int fd, void* entity, int size) {
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int remaining = size;
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int total_read = 0;
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while (remaining > 0) {
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int nread = read(fd, ((char*)entity)+total_read, remaining);
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if (nread == -1) {
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return nread;
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}
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remaining -= nread;
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total_read += nread;
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}
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return total_read;
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}
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void fill_buffer(size_t* written, char* dest, void *src, size_t n) {
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memcpy(dest+*written, src, n);
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*written += n;
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}
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