/* $OpenBSD: getpeereid_test.c,v 1.5 2024/08/23 12:56:26 anton Exp $ */
/* Written by Marc Espie in 2006 */
/* Public domain */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include <sys/wait.h>
#include <err.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>

char path[1024];
char *dir;

char *
check_id(int fd)
{
        uid_t sockuid, myuid;
        gid_t sockgid, mygid;
        static char problem[1024];

        if (getpeereid(fd, &sockuid, &sockgid) == -1) {
                snprintf(problem, sizeof problem, "getpeereid: %s", 
                    strerror(errno));
                return problem;
        }
        myuid = geteuid();
        mygid = getgid();
        if (myuid != sockuid) {
                snprintf(problem, sizeof problem, "uid discrepancy %ld vs %ld",
                        (long)myuid, (long)sockuid);
                return problem;
        }
        if (mygid != sockgid) {
                snprintf(problem, sizeof problem, "gid discrepancy %ld vs %ld",
                        (long)mygid, (long)sockgid);
                return problem;
        }
        return NULL;
}

void
client(struct sockaddr_un *sun)
{
        int s;
        int i;
        int r;
        char *problem;

        s = socket(AF_UNIX, SOCK_STREAM, 0);
        if (s == -1)
                err(1, "Bad socket");

        /* XXX make sure the server started alright */
        for (i = 0; i < 10; i++) {
                r = connect(s, (struct sockaddr *)sun, sizeof(*sun));
                if (r == 0) {
                        problem = check_id(s);
                        if (problem)
                                errx(1, "%s", problem);
                        exit(0);
                }
                sleep(5);
        }
        errx(1, "Could not connect after 10 tries");
}


void
server(struct sockaddr_un *sun)
{
        int s, fd;
        struct sockaddr_storage client_addr;
        socklen_t client_len;
        char *problem;

        s = socket(AF_UNIX, SOCK_STREAM, 0);
        if (s == -1)
                err(1, "Bad socket");

        if (bind(s, (struct sockaddr *)sun, sizeof(*sun)) != 0)
                err(1, "bind");
        if (listen(s, 5) != 0) {
                int saved_errno = errno;
                unlink(path);
                rmdir(dir);
                errc(1, saved_errno, "listen");
        }
        fd = accept(s, (struct sockaddr *)&client_addr, &client_len);
        if (fd == -1) {
                int saved_errno = errno;
                unlink(path);
                rmdir(dir);
                errc(1, saved_errno, "accept");
        }
        problem = check_id(fd);
        if (problem)  {
                unlink(path);
                rmdir(dir);
                errx(1, "%s", problem);
        }
        unlink(path);
        rmdir(dir);
}



int
main()
{
        pid_t pid;
        struct sockaddr_un sun;
        char dir_template[] = "/tmp/peer.XXXXXX";

        dir = mkdtemp(dir_template);
        if (!dir)
                err(1, "mkdtemp");
        snprintf(path, sizeof path, "%s/%s", dir, "socket");

        memset(&sun, 0, sizeof(struct sockaddr_un));
        if (strlcpy(sun.sun_path, path, sizeof(sun.sun_path)) >=
            sizeof(sun.sun_path))
                errx(1, "Memory error");
        sun.sun_family = AF_UNIX;

        /* let's make those two rendez-vous, a bit artificial */
        pid = fork();
        if (pid == -1)
                err(1, "can't fork");
        if (pid == 0) {
                client(&sun);
                exit(0);
        } else {
                int status;

                server(&sun);
                waitpid(pid, &status, 0);
                if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
                        printf("getpeereid test okay\n");
                        exit(0);
                } else {
                        errx(1, "Problem with child");
                }
        }
}