ネットワーク¶

 1
 2uv_loop_t *loop;
 3uv_udp_t send_socket;
 4uv_udp_t recv_socket;
 5
 6
 7int main() {
 8    loop = uv_default_loop();
 9
10    uv_udp_init(loop, &recv_socket);
11    struct sockaddr_in recv_addr;
12    uv_ip4_addr("0.0.0.0", 68, &recv_addr);
13    uv_udp_bind(&recv_socket, (const struct sockaddr *)&recv_addr, UV_UDP_REUSEADDR);
14    uv_udp_recv_start(&recv_socket, alloc_buffer, on_read);
15
16    uv_udp_init(loop, &send_socket);
17    struct sockaddr_in broadcast_addr;
18    uv_ip4_addr("0.0.0.0", 0, &broadcast_addr);
19    uv_udp_bind(&send_socket, (const struct sockaddr *)&broadcast_addr, 0);
20    uv_udp_set_broadcast(&send_socket, 1);
21
22    uv_udp_send_t send_req;
23    uv_buf_t discover_msg = make_discover_msg();
24
25    struct sockaddr_in send_addr;
26    uv_ip4_addr("255.255.255.255", 67, &send_addr);
27    uv_udp_send(&send_req, &send_socket, &discover_msg, 1, (const struct sockaddr *)&send_addr, on_send);
28
29    return uv_run(loop, UV_RUN_DEFAULT);
30}

 1void on_read(uv_udp_t *req, ssize_t nread, const uv_buf_t *buf, const struct sockaddr *addr, unsigned flags) {
 2    if (nread < 0) {
 3        fprintf(stderr, "Read error %s\n", uv_err_name(nread));
 4        uv_close((uv_handle_t*) req, NULL);
 5        free(buf->base);
 6        return;
 7    }
 8
 9    char sender[17] = { 0 };
10    uv_ip4_name((const struct sockaddr_in*) addr, sender, 16);
11    fprintf(stderr, "Recv from %s\n", sender);
12
13    // ... DHCP specific code
14    unsigned int *as_integer = (unsigned int*)buf->base;
15    unsigned int ipbin = ntohl(as_integer[4]);
16    unsigned char ip[4] = {0};
17    int i;
18    for (i = 0; i < 4; i++)
19        ip[i] = (ipbin >> i*8) & 0xff;
20    fprintf(stderr, "Offered IP %d.%d.%d.%d\n", ip[3], ip[2], ip[1], ip[0]);
21
22    free(buf->base);
23    uv_udp_recv_stop(req);
24}

 1
 2int main() {
 3    loop = uv_default_loop();
 4
 5    struct addrinfo hints;
 6    hints.ai_family = PF_INET;
 7    hints.ai_socktype = SOCK_STREAM;
 8    hints.ai_protocol = IPPROTO_TCP;
 9    hints.ai_flags = 0;
10
11    uv_getaddrinfo_t resolver;
12    fprintf(stderr, "irc.libera.chat is... ");
13    int r = uv_getaddrinfo(loop, &resolver, on_resolved, "irc.libera.chat", "6667", &hints);
14
15    if (r) {
16        fprintf(stderr, "getaddrinfo call error %s\n", uv_err_name(r));
17        return 1;
18    }
19    return uv_run(loop, UV_RUN_DEFAULT);
20}

 1
 2void on_resolved(uv_getaddrinfo_t *resolver, int status, struct addrinfo *res) {
 3    if (status < 0) {
 4        fprintf(stderr, "getaddrinfo callback error %s\n", uv_err_name(status));
 5        return;
 6    }
 7
 8    char addr[17] = {'\0'};
 9    uv_ip4_name((struct sockaddr_in*) res->ai_addr, addr, 16);
10    fprintf(stderr, "%s\n", addr);
11
12    uv_connect_t *connect_req = (uv_connect_t*) malloc(sizeof(uv_connect_t));
13    uv_tcp_t *socket = (uv_tcp_t*) malloc(sizeof(uv_tcp_t));
14    uv_tcp_init(loop, socket);
15
16    uv_tcp_connect(connect_req, socket, (const struct sockaddr*) res->ai_addr, on_connect);
17
18    uv_freeaddrinfo(res);
19}

 1#include <stdio.h>
 2#include <uv.h>
 3
 4int main() {
 5    char buf[512];
 6    uv_interface_address_t *info;
 7    int count, i;
 8
 9    uv_interface_addresses(&info, &count);
10    i = count;
11
12    printf("Number of interfaces: %d\n", count);
13    while (i--) {
14        uv_interface_address_t interface_a = info[i];
15
16        printf("Name: %s\n", interface_a.name);
17        printf("Internal? %s\n", interface_a.is_internal ? "Yes" : "No");
18        
19        if (interface_a.address.address4.sin_family == AF_INET) {
20            uv_ip4_name(&interface_a.address.address4, buf, sizeof(buf));
21            printf("IPv4 address: %s\n", buf);
22        }
23        else if (interface_a.address.address4.sin_family == AF_INET6) {
24            uv_ip6_name(&interface_a.address.address6, buf, sizeof(buf));
25            printf("IPv6 address: %s\n", buf);
26        }
27
28        printf("\n");
29    }
30
31    uv_free_interface_addresses(info, count);
32    return 0;
33}