OpenBSD套接字编程

Question

有一个动态 IP 地址（public 我家的 IP）我想跟踪（即，将其作为我的 OpenBSD 服务器上的文件）。我想出了这个简单的服务器：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<sys/socket.h>
#include<arpa/inet.h>
#include<unistd.h>

int
main(int argc, char *argv[])
{
    int             socket_desc,
                    new_socket,
                    c;
    struct sockaddr_in server,
                    client;
    char           *message;

    socket_desc = socket(AF_INET, SOCK_STREAM, 0);
    if (socket_desc == -1) {
        return 1;
    }

    server.sin_family = AF_INET;
    server.sin_addr.s_addr = INADDR_ANY;
    server.sin_port = htons(1234);

    if (bind(socket_desc, (struct sockaddr *) &server, sizeof(server)) < 0) {
        return 2;
    }

    listen(socket_desc, 3);

    for (;;) {
        c = sizeof(struct sockaddr_in);
        new_socket =
            accept(socket_desc, (struct sockaddr *) &client,
                   (socklen_t *) & c);
        if (new_socket < 0) {
            return 3;
        }

        int             client_port = ntohs(client.sin_port);
        char           *client_ip = inet_ntoa(client.sin_addr);
        for (int i = 0; i < 100; ++i) {
            if (client_ip[i] == 0)
                break;
            printf("%c", client_ip[i]);
        }
        printf("\n");
        write(new_socket, client_ip, strlen(client_ip));
        write(new_socket, "\n", 1);
    }
    return 0;
}

我在 Raspberry Pi（我的主计算机）运行 Raspberry Pi OS Buster（基本上是 Debian GNU/Linux Buster）上开发了它。它与 gcc(1) 和 tcc(1) 都能很好地编译。在我的 x86_64 Artix Linux 笔记本电脑上也是如此。但是，当我在 OpenBSD 上使用 cc(1)（即 Clang）尝试它时，我收到：

iplog4.c:14:24: error: variable has incomplete type 'struct sockaddr_in'
    struct sockaddr_in server,
                       ^
iplog4.c:14:12: note: forward declaration of 'struct sockaddr_in'
    struct sockaddr_in server,
           ^
iplog4.c:15:21: error: variable has incomplete type 'struct sockaddr_in'
                    client;
                    ^
iplog4.c:14:12: note: forward declaration of 'struct sockaddr_in'
    struct sockaddr_in server,
           ^
iplog4.c:26:30: error: use of undeclared identifier 'INADDR_ANY'
    server.sin_addr.s_addr = INADDR_ANY;
                             ^
iplog4.c:39:13: error: invalid application of 'sizeof' to an incomplete type 'struct sockaddr_in'
        c = sizeof(struct sockaddr_in);
            ^     ~~~~~~~~~~~~~~~~~~~~
iplog4.c:14:12: note: forward declaration of 'struct sockaddr_in'
    struct sockaddr_in server,
           ^
4 errors generated.

Answer 1

您需要以下包含才能编译：

#include <netinet/in.h>

OpenBSD套接字编程

OpenBSD Socket Programming

c

sockets

openbsd

bsd

clang