main.c File Reference

#include "postgres.h"
#include <unistd.h>
#include "bootstrap/bootstrap.h"
#include "common/username.h"
#include "port/atomics.h"
#include "postmaster/postmaster.h"
#include "storage/spin.h"
#include "tcop/tcopprot.h"
#include "utils/help_config.h"
#include "utils/memutils.h"
#include "utils/pg_locale.h"
#include "utils/ps_status.h"

Include dependency graph for main.c:

Go to the source code of this file.

Functions
static void	startup_hacks (const char *progname)
static void	init_locale (const char *categoryname, int category, const char *locale)
static void	help (const char *progname)
static void	check_root (const char *progname)
int	main (int argc, char *argv[])

Variables
const char *	progname

Function Documentation

check_root()

static void check_root ( const char *  progname )

static

Definition at line 408 of file main.c.

{
#ifndef WIN32
    if (geteuid() == 0)
    {
        write_stderr("\"root\" execution of the PostgreSQL server is not permitted.\n"
                     "The server must be started under an unprivileged user ID to prevent\n"
                     "possible system security compromise.  See the documentation for\n"
                     "more information on how to properly start the server.\n");
        exit(1);
    }
 
    /*
     * Also make sure that real and effective uids are the same. Executing as
     * a setuid program from a root shell is a security hole, since on many
     * platforms a nefarious subroutine could setuid back to root if real uid
     * is root.  (Since nobody actually uses postgres as a setuid program,
     * trying to actively fix this situation seems more trouble than it's
     * worth; we'll just expend the effort to check for it.)
     */
    if (getuid() != geteuid())
    {
        write_stderr("%s: real and effective user IDs must match\n",
                     progname);
        exit(1);
    }
#else                           /* WIN32 */
    if (pgwin32_is_admin())
    {
        write_stderr("Execution of PostgreSQL by a user with administrative permissions is not\n"
                     "permitted.\n"
                     "The server must be started under an unprivileged user ID to prevent\n"
                     "possible system security compromises.  See the documentation for\n"
                     "more information on how to properly start the server.\n");
        exit(1);
    }
#endif                          /* WIN32 */
}

References exit(), pgwin32_is_admin(), progname, and write_stderr.

Referenced by main().

help()

static void help ( const char *  progname )

static

Definition at line 348 of file main.c.

{
    printf(_("%s is the PostgreSQL server.\n\n"), progname);
    printf(_("Usage:\n  %s [OPTION]...\n\n"), progname);
    printf(_("Options:\n"));
    printf(_("  -B NBUFFERS        number of shared buffers\n"));
    printf(_("  -c NAME=VALUE      set run-time parameter\n"));
    printf(_("  -C NAME            print value of run-time parameter, then exit\n"));
    printf(_("  -d 1-5             debugging level\n"));
    printf(_("  -D DATADIR         database directory\n"));
    printf(_("  -e                 use European date input format (DMY)\n"));
    printf(_("  -F                 turn fsync off\n"));
    printf(_("  -h HOSTNAME        host name or IP address to listen on\n"));
    printf(_("  -i                 enable TCP/IP connections\n"));
    printf(_("  -k DIRECTORY       Unix-domain socket location\n"));
#ifdef USE_SSL
    printf(_("  -l                 enable SSL connections\n"));
#endif
    printf(_("  -N MAX-CONNECT     maximum number of allowed connections\n"));
    printf(_("  -p PORT            port number to listen on\n"));
    printf(_("  -s                 show statistics after each query\n"));
    printf(_("  -S WORK-MEM        set amount of memory for sorts (in kB)\n"));
    printf(_("  -V, --version      output version information, then exit\n"));
    printf(_("  --NAME=VALUE       set run-time parameter\n"));
    printf(_("  --describe-config  describe configuration parameters, then exit\n"));
    printf(_("  -?, --help         show this help, then exit\n"));
 
    printf(_("\nDeveloper options:\n"));
    printf(_("  -f s|i|n|m|h       forbid use of some plan types\n"));
    printf(_("  -n                 do not reinitialize shared memory after abnormal exit\n"));
    printf(_("  -O                 allow system table structure changes\n"));
    printf(_("  -P                 disable system indexes\n"));
    printf(_("  -t pa|pl|ex        show timings after each query\n"));
    printf(_("  -T                 send SIGSTOP to all backend processes if one dies\n"));
    printf(_("  -W NUM             wait NUM seconds to allow attach from a debugger\n"));
 
    printf(_("\nOptions for single-user mode:\n"));
    printf(_("  --single           selects single-user mode (must be first argument)\n"));
    printf(_("  DBNAME             database name (defaults to user name)\n"));
    printf(_("  -d 0-5             override debugging level\n"));
    printf(_("  -E                 echo statement before execution\n"));
    printf(_("  -j                 do not use newline as interactive query delimiter\n"));
    printf(_("  -r FILENAME        send stdout and stderr to given file\n"));
 
    printf(_("\nOptions for bootstrapping mode:\n"));
    printf(_("  --boot             selects bootstrapping mode (must be first argument)\n"));
    printf(_("  --check            selects check mode (must be first argument)\n"));
    printf(_("  DBNAME             database name (mandatory argument in bootstrapping mode)\n"));
    printf(_("  -r FILENAME        send stdout and stderr to given file\n"));
 
    printf(_("\nPlease read the documentation for the complete list of run-time\n"
             "configuration settings and how to set them on the command line or in\n"
             "the configuration file.\n\n"
             "Report bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
}

References _, printf, and progname.

Referenced by main().

init_locale()

static void init_locale ( const char *  categoryname, int  category, const char *  locale  )

static

Definition at line 329 of file main.c.

{
    if (pg_perm_setlocale(category, locale) == NULL &&
        pg_perm_setlocale(category, "C") == NULL)
        elog(FATAL, "could not adopt \"%s\" locale nor C locale for %s",
             locale, categoryname);
}

References elog, FATAL, locale, and pg_perm_setlocale().

Referenced by main().

main()

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 63 of file main.c.

{
    bool        do_check_root = true;
 
    /*
     * If supported on the current platform, set up a handler to be called if
     * the backend/postmaster crashes with a fatal signal or exception.
     */
#if defined(WIN32) && defined(HAVE_MINIDUMP_TYPE)
    pgwin32_install_crashdump_handler();
#endif
 
    progname = get_progname(argv[0]);
 
    /*
     * Platform-specific startup hacks
     */
    startup_hacks(progname);
 
    /*
     * Remember the physical location of the initially given argv[] array for
     * possible use by ps display.  On some platforms, the argv[] storage must
     * be overwritten in order to set the process title for ps. In such cases
     * save_ps_display_args makes and returns a new copy of the argv[] array.
     *
     * save_ps_display_args may also move the environment strings to make
     * extra room. Therefore this should be done as early as possible during
     * startup, to avoid entanglements with code that might save a getenv()
     * result pointer.
     */
    argv = save_ps_display_args(argc, argv);
 
    /*
     * Fire up essential subsystems: error and memory management
     *
     * Code after this point is allowed to use elog/ereport, though
     * localization of messages may not work right away, and messages won't go
     * anywhere but stderr until GUC settings get loaded.
     */
    MemoryContextInit();
 
    /*
     * Set up locale information
     */
    set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("postgres"));
 
    /*
     * In the postmaster, absorb the environment values for LC_COLLATE and
     * LC_CTYPE.  Individual backends will change these later to settings
     * taken from pg_database, but the postmaster cannot do that.  If we leave
     * these set to "C" then message localization might not work well in the
     * postmaster.
     */
    init_locale("LC_COLLATE", LC_COLLATE, "");
    init_locale("LC_CTYPE", LC_CTYPE, "");
 
    /*
     * LC_MESSAGES will get set later during GUC option processing, but we set
     * it here to allow startup error messages to be localized.
     */
#ifdef LC_MESSAGES
    init_locale("LC_MESSAGES", LC_MESSAGES, "");
#endif
 
    /*
     * We keep these set to "C" always, except transiently in pg_locale.c; see
     * that file for explanations.
     */
    init_locale("LC_MONETARY", LC_MONETARY, "C");
    init_locale("LC_NUMERIC", LC_NUMERIC, "C");
    init_locale("LC_TIME", LC_TIME, "C");
 
    /*
     * Now that we have absorbed as much as we wish to from the locale
     * environment, remove any LC_ALL setting, so that the environment
     * variables installed by pg_perm_setlocale have force.
     */
    unsetenv("LC_ALL");
 
    check_strxfrm_bug();
 
    /*
     * Catch standard options before doing much else, in particular before we
     * insist on not being root.
     */
    if (argc > 1)
    {
        if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
        {
            help(progname);
            exit(0);
        }
        if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
        {
            fputs(PG_BACKEND_VERSIONSTR, stdout);
            exit(0);
        }
 
        /*
         * In addition to the above, we allow "--describe-config" and "-C var"
         * to be called by root.  This is reasonably safe since these are
         * read-only activities.  The -C case is important because pg_ctl may
         * try to invoke it while still holding administrator privileges on
         * Windows.  Note that while -C can normally be in any argv position,
         * if you want to bypass the root check you must put it first.  This
         * reduces the risk that we might misinterpret some other mode's -C
         * switch as being the postmaster/postgres one.
         */
        if (strcmp(argv[1], "--describe-config") == 0)
            do_check_root = false;
        else if (argc > 2 && strcmp(argv[1], "-C") == 0)
            do_check_root = false;
    }
 
    /*
     * Make sure we are not running as root, unless it's safe for the selected
     * option.
     */
    if (do_check_root)
        check_root(progname);
 
    /*
     * Dispatch to one of various subprograms depending on first argument.
     */
 
    if (argc > 1 && strcmp(argv[1], "--check") == 0)
        BootstrapModeMain(argc, argv, true);
    else if (argc > 1 && strcmp(argv[1], "--boot") == 0)
        BootstrapModeMain(argc, argv, false);
#ifdef EXEC_BACKEND
    else if (argc > 1 && strncmp(argv[1], "--fork", 6) == 0)
        SubPostmasterMain(argc, argv);
#endif
    else if (argc > 1 && strcmp(argv[1], "--describe-config") == 0)
        GucInfoMain();
    else if (argc > 1 && strcmp(argv[1], "--single") == 0)
        PostgresSingleUserMain(argc, argv,
                               strdup(get_user_name_or_exit(progname)));
    else
        PostmasterMain(argc, argv);
    /* the functions above should not return */
    abort();
}

References BootstrapModeMain(), check_root(), check_strxfrm_bug(), exit(), get_progname(), get_user_name_or_exit(), GucInfoMain(), help(), init_locale(), MemoryContextInit(), PG_BACKEND_VERSIONSTR, PG_TEXTDOMAIN, pgwin32_install_crashdump_handler(), PostgresSingleUserMain(), PostmasterMain(), progname, save_ps_display_args(), set_pglocale_pgservice(), startup_hacks(), generate_unaccent_rules::stdout, and unsetenv.

startup_hacks()

static void startup_hacks ( const char *  progname )

static

Definition at line 221 of file main.c.

{
    /*
     * Windows-specific execution environment hacking.
     */
#ifdef WIN32
    {
        WSADATA     wsaData;
        int         err;
 
        /* Make output streams unbuffered by default */
        setvbuf(stdout, NULL, _IONBF, 0);
        setvbuf(stderr, NULL, _IONBF, 0);
 
        /* Prepare Winsock */
        err = WSAStartup(MAKEWORD(2, 2), &wsaData);
        if (err != 0)
        {
            write_stderr("%s: WSAStartup failed: %d\n",
                         progname, err);
            exit(1);
        }
 
        /*
         * By default abort() only generates a crash-dump in *non* debug
         * builds. As our Assert() / ExceptionalCondition() uses abort(),
         * leaving the default in place would make debugging harder.
         *
         * MINGW's own C runtime doesn't have _set_abort_behavior(). When
         * targeting Microsoft's UCRT with mingw, it never links to the debug
         * version of the library and thus doesn't need the call to
         * _set_abort_behavior() either.
         */
#if !defined(__MINGW32__) && !defined(__MINGW64__)
        _set_abort_behavior(_CALL_REPORTFAULT | _WRITE_ABORT_MSG,
                            _CALL_REPORTFAULT | _WRITE_ABORT_MSG);
#endif                          /* !defined(__MINGW32__) &&
                                 * !defined(__MINGW64__) */
 
        /*
         * SEM_FAILCRITICALERRORS causes more errors to be reported to
         * callers.
         *
         * We used to also specify SEM_NOGPFAULTERRORBOX, but that prevents
         * windows crash reporting from working. Which includes registered
         * just-in-time debuggers, making it unnecessarily hard to debug
         * problems on windows. Now we try to disable sources of popups
         * separately below (note that SEM_NOGPFAULTERRORBOX did not actually
         * prevent all sources of such popups).
         */
        SetErrorMode(SEM_FAILCRITICALERRORS);
 
        /*
         * Show errors on stderr instead of popup box (note this doesn't
         * affect errors originating in the C runtime, see below).
         */
        _set_error_mode(_OUT_TO_STDERR);
 
        /*
         * In DEBUG builds, errors, including assertions, C runtime errors are
         * reported via _CrtDbgReport. By default such errors are displayed
         * with a popup (even with NOGPFAULTERRORBOX), preventing forward
         * progress. Instead report such errors stderr (and the debugger).
         * This is C runtime specific and thus the above incantations aren't
         * sufficient to suppress these popups.
         */
        _CrtSetReportMode(_CRT_ERROR, _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
        _CrtSetReportFile(_CRT_ERROR, _CRTDBG_FILE_STDERR);
        _CrtSetReportMode(_CRT_ASSERT, _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
        _CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
        _CrtSetReportMode(_CRT_WARN, _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
        _CrtSetReportFile(_CRT_WARN, _CRTDBG_FILE_STDERR);
 
#if defined(_M_AMD64) && _MSC_VER == 1800
 
        /*----------
         * Avoid crashing in certain floating-point operations if we were
         * compiled for x64 with MS Visual Studio 2013 and are running on
         * Windows prior to 7/2008R2 SP1 on an AVX2-capable CPU.
         *
         * Ref: https://connect.microsoft.com/VisualStudio/feedback/details/811093/visual-studio-2013-rtm-c-x64-code-generation-bug-for-avx2-instructions
         *----------
         */
        if (!IsWindows7SP1OrGreater())
        {
            _set_FMA3_enable(0);
        }
#endif                          /* defined(_M_AMD64) && _MSC_VER == 1800 */
 
    }
#endif                          /* WIN32 */
 
    /*
     * Initialize dummy_spinlock, in case we are on a platform where we have
     * to use the fallback implementation of pg_memory_barrier().
     */
    SpinLockInit(&dummy_spinlock);
}

References dummy_spinlock, exit(), progname, SpinLockInit, generate_unaccent_rules::stdout, and write_stderr.

Referenced by main().

Variable Documentation

progname

const char* progname

Definition at line 50 of file main.c.

Referenced by _check_database_version(), BootstrapModeMain(), check_root(), checkControlFile(), cluster_all_databases(), cluster_one_database(), ConnectDatabase(), connectDatabase(), connectMaintenanceDatabase(), get_opts(), get_progname(), get_user_name_or_exit(), help(), main(), ParallelSlotsSetup(), PostgresSingleUserMain(), PostmasterMain(), process_postgres_switches(), reindex_all_databases(), reindex_one_database(), SelectConfigFiles(), sigTermHandler(), startup_hacks(), usage(), vacuum_all_databases(), and vacuum_one_database().