src/lib/hostpid.c

	hostpid.c revision a8aec60b5359e5ea7fc7a9464217ae3626df8785
/* Copyright (c) 2002-2013 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "hostpid.h"

#include <stdlib.h>
#include <unistd.h>
#include <netdb.h>

#define HOSTNAME_DISALLOWED_CHARS "/\r\n\t"

const char *my_hostname = NULL;
const char *my_pid = NULL;

static char *my_domain = NULL;

void hostpid_init(void)
{
    static char hostname[256], pid[MAX_INT_STRLEN];

    my_hostname = getenv(MY_HOSTNAME_ENV);
    if (my_hostname == NULL) {
        if (gethostname(hostname, sizeof(hostname)-1) < 0)
            i_fatal("gethostname() failed: %m");
        hostname[sizeof(hostname)-1] = '\0';
        my_hostname = hostname;
    }

    if (my_hostname[0] == '\0' ||
        strcspn(my_hostname, HOSTNAME_DISALLOWED_CHARS) != strlen(my_hostname))
        i_error("Invalid system hostname: '%s'", my_hostname);

    /* allow calling hostpid_init() multiple times to reset hostname */
    i_free_and_null(my_domain);

    i_snprintf(pid, sizeof(pid), "%lld", (long long)getpid());
    my_pid = pid;
}

void hostpid_deinit(void)
{
    i_free(my_domain);
}

const char *my_hostdomain(void)
{
    struct hostent *hent;
    const char *name;

    if (my_domain == NULL) {
        name = getenv(MY_HOSTDOMAIN_ENV);
        if (name == NULL) {
            hent = gethostbyname(my_hostname);
            name = hent != NULL ? hent->h_name : NULL;
            if (name == NULL) {
                /* failed, use just the hostname */
                name = my_hostname;
            }
        }
        my_domain = i_strdup(name);
    }
    return my_domain;
}