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- /*++
- Copyright (c) 2015 Minoca Corp. All Rights Reserved
- Module Name:
- vlock.c
- Abstract:
- This module implements the vlock command, which locks a terminal until a
- password unlocks it.
- Author:
- Evan Green 12-Mar-2015
- Environment:
- POSIX
- --*/
- //
- // ------------------------------------------------------------------- Includes
- //
- #include <minoca/lib/types.h>
- #include <assert.h>
- #include <errno.h>
- #include <getopt.h>
- #include <grp.h>
- #include <pwd.h>
- #include <shadow.h>
- #include <signal.h>
- #include <stdlib.h>
- #include <string.h>
- #include <termios.h>
- #include <unistd.h>
- #include "../swlib.h"
- #include "lutil.h"
- //
- // ---------------------------------------------------------------- Definitions
- //
- #define VLOCK_VERSION_MAJOR 1
- #define VLOCK_VERSION_MINOR 0
- #define VLOCK_USAGE \
- "usage: vlock\n" \
- "The vlock utility locks a terminal, requiring the user's password to \n" \
- "unlock it. Options are:\n" \
- " --help -- Displays this help text and exits.\n" \
- " --version -- Displays the application version and exits.\n"
- #define VLOCK_OPTIONS_STRING "HV"
- //
- // ------------------------------------------------------ Data Type Definitions
- //
- //
- // ----------------------------------------------- Internal Function Prototypes
- //
- //
- // -------------------------------------------------------------------- Globals
- //
- struct option VlockLongOptions[] = {
- {"help", no_argument, 0, 'H'},
- {"version", no_argument, 0, 'V'},
- {NULL, 0, 0, 0},
- };
- //
- // ------------------------------------------------------------------ Functions
- //
- INT
- VlockMain (
- INT ArgumentCount,
- CHAR **Arguments
- )
- /*++
- Routine Description:
- This routine is the main entry point for the vlock utility.
- Arguments:
- ArgumentCount - Supplies the number of command line arguments the program
- was invoked with.
- Arguments - Supplies a tokenized array of command line arguments.
- Return Value:
- Returns an integer exit code. 0 for success, nonzero otherwise.
- --*/
- {
- ULONG ArgumentIndex;
- struct sigaction NewAction;
- struct termios NewSettings;
- INT Option;
- struct termios OriginalSettings;
- struct sigaction SaveAlarm;
- struct sigaction SaveHup;
- struct sigaction SaveInt;
- struct sigaction SavePipe;
- struct sigaction SaveQuit;
- struct sigaction SaveTerm;
- struct sigaction SaveTstop;
- struct sigaction SaveTtin;
- struct sigaction SaveTtou;
- int Status;
- struct passwd *User;
- uid_t UserId;
- UserId = getuid();
- User = getpwuid(UserId);
- if (User == NULL) {
- SwPrintError(0,
- NULL,
- "Cannot get user information for user ID %d.\n",
- UserId);
- Status = 1;
- goto MainEnd;
- }
- //
- // Process the control arguments.
- //
- while (TRUE) {
- Option = getopt_long(ArgumentCount,
- Arguments,
- VLOCK_OPTIONS_STRING,
- VlockLongOptions,
- NULL);
- if (Option == -1) {
- break;
- }
- if ((Option == '?') || (Option == ':')) {
- Status = 1;
- goto MainEnd;
- }
- switch (Option) {
- case 'V':
- SwPrintVersion(VLOCK_VERSION_MAJOR, VLOCK_VERSION_MINOR);
- return 1;
- case 'H':
- printf(VLOCK_USAGE);
- return 1;
- default:
- assert(FALSE);
- Status = 1;
- goto MainEnd;
- }
- }
- ArgumentIndex = optind;
- if (ArgumentIndex > ArgumentCount) {
- ArgumentIndex = ArgumentCount;
- }
- if (ArgumentIndex != ArgumentCount) {
- SwPrintError(0, NULL, "Unexpected argument");
- Status = 1;
- goto MainEnd;
- }
- if (SwCheckAccount(User) != 0) {
- SwPrintError(0, User->pw_name, "Not locking terminal for account");
- Status = 1;
- goto MainEnd;
- }
- //
- // Turn off echoing, signals and breaks.
- //
- if (tcgetattr(STDIN_FILENO, &OriginalSettings) != 0) {
- Status = 1;
- goto MainEnd;
- }
- memcpy(&NewSettings, &OriginalSettings, sizeof(struct termios));
- NewSettings.c_iflag &= ~(BRKINT | ISIG | ECHO);
- NewSettings.c_iflag |= IGNBRK;
- if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &NewSettings) != 0) {
- Status = 1;
- goto MainEnd;
- }
- //
- // Handle all signals so that the terminal settings can be put back.
- //
- sigemptyset(&(NewAction.sa_mask));
- NewAction.sa_flags = 0;
- NewAction.sa_handler = SIG_IGN;
- sigaction(SIGALRM, &NewAction, &SaveAlarm);
- sigaction(SIGHUP, &NewAction, &SaveHup);
- sigaction(SIGINT, &NewAction, &SaveInt);
- sigaction(SIGPIPE, &NewAction, &SavePipe);
- sigaction(SIGQUIT, &NewAction, &SaveQuit);
- sigaction(SIGTERM, &NewAction, &SaveTerm);
- sigaction(SIGTSTP, &NewAction, &SaveTstop);
- sigaction(SIGTTIN, &NewAction, &SaveTtin);
- sigaction(SIGTTOU, &NewAction, &SaveTtou);
- while (TRUE) {
- printf("Console locked by %s.\n", User->pw_name);
- Status = SwGetAndCheckPassword(User, NULL);
- if (Status == 0) {
- break;
- }
- sleep(LOGIN_FAIL_DELAY);
- printf("vlock: Incorrect password.\n");
- }
- //
- // Restore the original terminal settings.
- //
- tcsetattr(STDIN_FILENO, TCSAFLUSH, &OriginalSettings);
- //
- // Restore the original signal handlers.
- //
- sigaction(SIGALRM, &SaveAlarm, NULL);
- sigaction(SIGHUP, &SaveHup, NULL);
- sigaction(SIGINT, &SaveInt, NULL);
- sigaction(SIGPIPE, &SavePipe, NULL);
- sigaction(SIGQUIT, &SaveQuit, NULL);
- sigaction(SIGTERM, &SaveTerm, NULL);
- sigaction(SIGTSTP, &SaveTstop, NULL);
- sigaction(SIGTTIN, &SaveTtin, NULL);
- sigaction(SIGTTOU, &SaveTtou, NULL);
- Status = 0;
- MainEnd:
- return Status;
- }
- //
- // --------------------------------------------------------- Internal Functions
- //
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