/*
 * This file and its contents are supplied under the terms of the
 * Common Development and Distribution License ("CDDL"), version 1.0.
 * You may only use this file in accordance with the terms of version
 * 1.0 of the CDDL.
 *
 * A full copy of the text of the CDDL should have accompanied this
 * source.  A copy of the CDDL is also available via the Internet at
 * http://www.illumos.org/license/CDDL.
 */

/*
 * Copyright 2013 Nexenta Systems, Inc.  All rights reserved.
 */

/*
 * fork/exec a privileged helper to do the bind.
 */

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/socket.h>
#include <sys/note.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int
ksocket_bind_helper(int fd, struct sockaddr *addr, uint_t addrlen)
{
        char familystr[8];
        char portstr[12];
        char addrstr[INET6_ADDRSTRLEN];
        char *argv[6];
        const char *p;
        /* LINTED E_BAD_PTR_CAST_ALIGN */
        struct sockaddr_in  *sin  = (struct sockaddr_in *)addr;
        /* LINTED E_BAD_PTR_CAST_ALIGN */
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)addr;
        int pid, err, stat;
        _NOTE(ARGUNUSED(addrlen));

        (void) snprintf(familystr, sizeof (familystr), "%d", addr->sa_family);
        switch (addr->sa_family) {
        case AF_INET:
                (void) snprintf(portstr, sizeof (portstr), "%d",
                    ntohs(sin->sin_port));
                p = inet_ntop(AF_INET, &sin->sin_addr,
                    addrstr, sizeof (addrstr));
                break;
        case AF_INET6:
                (void) snprintf(portstr, sizeof (portstr), "%d",
                    ntohs(sin6->sin6_port));
                p = inet_ntop(AF_INET6, &sin6->sin6_addr,
                    addrstr, sizeof (addrstr));
                break;
        default:
                p = NULL;
                break;
        }
        if (p == NULL) {
                err = errno;
                (void) fprintf(stdout, "ksocket_bind_helper, inet_ntop %s\n",
                    strerror(err));
                return (err);
        }

        (void) fprintf(stdout, "ksocket_bind_helper, "
            "family=%s addr=%s port=%s\n",
            familystr, addrstr, portstr);

        argv[0] = "/usr/bin/pfexec";
        argv[1] = "/usr/lib/smbsrv/bind-helper";
        argv[2] = familystr;
        argv[3] = addrstr;
        argv[4] = portstr;
        argv[5] = NULL;

        pid = vfork();
        if (pid == -1) {
                err = errno;
                perror("fork");
                return (err);
        }
        if (pid == 0) {
                (void) dup2(fd, 0);
                (void) execv(argv[0], argv);
                err = errno;
                perror("execv");
                return (err);
        }
        err = waitpid(pid, &stat, 0);
        if (err == -1) {
                err = errno;
                perror("waitpid");
                return (err);
        }
        if (WIFEXITED(stat)) {
                err = WEXITSTATUS(stat);
                if (err == 0)
                        return (0);
                (void) fprintf(stderr, "helper exit %d\n", err);
        }
        return (EACCES);
}