sun-src/os/dtlogin.c

	dtlogin.c revision 766
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive/* Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive *
34420effba1fde4ef7a4aaadba1c92ac0c8be339fielding * Permission is hereby granted, free of charge, to any person obtaining a
34420effba1fde4ef7a4aaadba1c92ac0c8be339fielding * copy of this software and associated documentation files (the
34420effba1fde4ef7a4aaadba1c92ac0c8be339fielding * "Software"), to deal in the Software without restriction, including
34420effba1fde4ef7a4aaadba1c92ac0c8be339fielding * without limitation the rights to use, copy, modify, merge, publish,
34420effba1fde4ef7a4aaadba1c92ac0c8be339fielding * distribute, and/or sell copies of the Software, and to permit persons
34420effba1fde4ef7a4aaadba1c92ac0c8be339fielding * to whom the Software is furnished to do so, provided that the above
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd * copyright notice(s) and this permission notice appear in all copies of
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd * the Software and that both the above copyright notice(s) and this
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd * permission notice appear in supporting documentation.
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd *
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd * OF THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
273eafe6bf1d6f7e307eada091fef9a80ab1f440nd * HOLDERS INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive *
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * Except as contained in this notice, the name of a copyright holder
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * shall not be used in advertising or otherwise to promote the sale, use
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * or other dealings in this Software without prior written authorization
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * of the copyright holder.
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive */
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#pragma ident "@(#)dtlogin.c    1.19    09/08/14   SMI"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive/* Implementation of Display Manager (dtlogin/gdm/xdm/etc.) to X server
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * communication pipe. The Display Manager process will start
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * the X window server at system boot time before any user
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * has logged into the system.  The X server is by default
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * started as the root UID "0".
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive *
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * At login time the Xserver local communication pipe is provided
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * by the Xserver for user specific configuration data supplied
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * by the display manager.  It notifies the Xserver it needs to change
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * over to the user's credentials (UID, GID, GID_LIST) and
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * also switch CWD (current working directory) of to match
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * the user's CWD home.
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive * ASARC case 1995/390
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive */
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <X11/Xos.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <sys/param.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <sys/socket.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <netinet/in.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <netdb.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <stdio.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <fcntl.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <sys/types.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <sys/stat.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <errno.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <X11/X.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <X11/Xmd.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include "misc.h"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <X11/Xpoll.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include "osdep.h"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include "input.h"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include "dixstruct.h"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include "dixfont.h"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include "opaque.h"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <pwd.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <project.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <sys/task.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <ctype.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include "scrnintstr.h"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include <sys/vt.h>
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#ifdef XSUN
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#include "sunIo.h"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#endif
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#define DTLOGIN_PATH "/var/dt/sdtlogin"
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive#define BUFLEN 1024
3fa58e00171aebf3b2cfa90035ed530f5b1f651dslive
3fa58e00171aebf3b2cfa90035ed530f5b1f651dsliveuid_t   root_euid;
3fa58e00171aebf3b2cfa90035ed530f5b1f651dsliveint xf86ConsoleFd = -1;

/* in Xserver/os/auth.c */
extern const char *GetAuthFilename(void);

/* Data passed to block/wakeup handlers */
struct dmdata {
    int     pipeFD;
    char *  pipename;   /* path to pipe */
    char *  buf;        /* contains characters to be processed */
    int     bufsize;    /* size allocated for buf */
    /* Data about the user we need to switch to */
    uid_t   uid;
    gid_t   gid;            /* Primary group */
    gid_t   groupids[NGROUPS_UMAX]; /* Supplementary groups */
    int     groupid_cnt;
    char *  homedir;
};

static void DtloginBlockHandler(pointer, struct timeval **, pointer);
static void DtloginWakeupHandler(pointer, int, pointer);
static int  dtlogin_create_pipe(int, struct dmdata *);
static void dtlogin_receive_packet(struct dmdata *);
static int  dtlogin_parse_packet(struct dmdata *, char *);
static void dtlogin_process(struct dmdata *dmd);
static void dtlogin_close_pipe(struct dmdata *);

#define DtloginError(str)   Error(str)
#define DtloginFatal(str)   FatalError("%s\n", str)

#ifndef XSUN
# define DtloginInfo(fmt, arg)  LogMessageVerb(X_INFO, 5, fmt, arg)
#elif defined(DEBUG)
# define DtloginInfo(fmt, arg)  fprintf(stderr, fmt, arg)
#else
# define DtloginInfo(fmt, arg)  /* Do nothing */
#endif

/*
 * initialize DTLOGIN: create pipe; set handlers.
 * Called from CreateWellKnownSockets in os/connection.c
 */

_X_HIDDEN void
DtloginInit(void)
{
    int displayNumber = 0;
    struct dmdata *dmd;

    if (serverGeneration != 1) return;

    root_euid = geteuid();

    if (getuid() != 0)  return;

    dmd = Xcalloc(sizeof(struct dmdata));
    if (dmd == NULL) {
    DtloginError("Not enough memory to create display manager pipe");
    return;
    }

    dmd->uid = (uid_t) -1;
    dmd->gid = (gid_t) -1;

    displayNumber = atoi(display); /* Assigned in dix/main.c */

    dmd->pipeFD = dtlogin_create_pipe(displayNumber, dmd);

    if (dmd->pipeFD == -1) {
    xfree(dmd);
    return;
    }

    RegisterBlockAndWakeupHandlers (DtloginBlockHandler,
                    DtloginWakeupHandler,
                    (pointer) dmd);
}

static void
DtloginBlockHandler(
    pointer         data,
    struct timeval  **wt, /* unused */
    pointer         pReadmask)
{
    struct dmdata *dmd = (struct dmdata *) data;
    fd_set *LastSelectMask = (fd_set*)pReadmask;

    FD_SET(dmd->pipeFD, LastSelectMask);
}

static void
DtloginWakeupHandler(
    pointer data,   /* unused */
    int     i,
    pointer pReadmask)
{
    struct dmdata *dmd = (struct dmdata *) data;
    fd_set* LastSelectMask = (fd_set*)pReadmask;

    if (i > 0)
    {
        if (FD_ISSET(dmd->pipeFD, LastSelectMask))
        {
            FD_CLR(dmd->pipeFD, LastSelectMask);
            dtlogin_receive_packet(dmd);
        /* dmd may have been freed in dtlogin_receive_packet, do
           not use after this point */
        }
    }
}

static int
dtlogin_create_pipe(int port, struct dmdata *dmd)
{
    struct stat statbuf;
    char pipename[128];
    int pipeFD = -1;

    if (stat(DTLOGIN_PATH, &statbuf) == -1) {
    if (mkdir(DTLOGIN_PATH, 0700) == -1) {
        DtloginError("Cannot create " DTLOGIN_PATH
             " directory for display manager pipe");
        return -1;
    }
    } else if (!S_ISDIR(statbuf.st_mode)) {
    DtloginError("Cannot create display manager pipe: "
             DTLOGIN_PATH " is not a directory");
        return -1;
    }

    snprintf(pipename, sizeof(pipename), "%s/%d", DTLOGIN_PATH, port);

    if (mkfifo(pipename, S_IRUSR | S_IWUSR) < 0)
        return -1;

    if ((pipeFD = open(pipename, O_RDONLY | O_NONBLOCK)) < 0) {
    remove(pipename);
        return -1;
    }

    dmd->pipename = xstrdup(pipename);

    /* To make sure root has rw permissions. */
    (void) fchmod(pipeFD, 0600);

#ifdef XSUN
    if (pipeFD >= cur_max_socks)
    cur_max_socks = pipeFD + 1;
#endif

    return pipeFD;
}

static void dtlogin_close_pipe(struct dmdata *dmd)
{
    RemoveBlockAndWakeupHandlers (DtloginBlockHandler,
                  DtloginWakeupHandler, dmd);

    close(dmd->pipeFD);
    remove(dmd->pipename);
    xfree(dmd->pipename);
    xfree(dmd->buf);
    xfree(dmd->homedir);
    xfree(dmd);
}

static void
dtlogin_receive_packet(struct dmdata *dmd)
{
    int bufLen, nbRead;
    char *p, *n;
    int done = 0;

    if (dmd->buf == NULL) {
    dmd->bufsize = BUFLEN;
    dmd->buf = xalloc(dmd->bufsize);
    dmd->buf[0] = '\0';
    }

    /* Read data from pipe and split into tokens, buffering the rest */
    while (!done) {
    bufLen = strlen(dmd->buf);

    /*
     * Realloc only if buf has filled up and we don't have a record
     * delimiter yet. Keep track of alloced size.
     */
    if (bufLen > (dmd->bufsize/2)) {
        dmd->bufsize += BUFLEN;
        dmd->buf = xrealloc(dmd->buf, dmd->bufsize);
    }

    nbRead = read(dmd->pipeFD, dmd->buf + bufLen,
              dmd->bufsize - bufLen - 1);

    if (nbRead == -1) {
        if (errno == EINTR) {
        continue;
        } else if (errno == EAGAIN) {
        return;     /* return to WaitFor, wait for select() */
        } else {
        dtlogin_close_pipe(dmd);
        return;
        }
    }

    if (nbRead == 0) { /* End of file */
        dtlogin_close_pipe(dmd);
        return;
    }

    bufLen += nbRead;
    dmd->buf[bufLen] = '\0';

    DtloginInfo("Data buffer: %s\n", dmd->buf);

    p = dmd->buf;
    while ((n = strchr(p, ';')) != NULL) { /* Next complete packet */
        *n = '\0';
        DtloginInfo("Next packet: %s\n", p);
        done = dtlogin_parse_packet(dmd, p);
        if (done) {
        dtlogin_close_pipe(dmd);    /* free's dmd */
        return;
        }
        p = n+1;
    }

    /* save the rest for the next iteration */
    if (p < (dmd->buf + bufLen)) {
        DtloginInfo("Left over: %s\n", p);
        strcpy(dmd->buf, p);
    }
    }
}

/* Parse data from packet
 *
 * Example Record:
 *      UID="xxx" GID="yyy";
 *      G_LIST_ID="aaa" G_LIST_ID="bbb" G_LIST_ID="ccc";
 *      HOME="/nn/mmm/ooo" EOF="";
 */
static int
dtlogin_parse_packet(struct dmdata *dmd, char *s)
{
    char *k, *v, *p;

    while (s < (dmd->buf + dmd->bufsize)) {
    /* format is key="value" - split into key & value pair */

    for (k = s ; (*k != '\0') && isspace(*k); k++) {
        /* Skip over whitespace */
    }

    if (*k == '\0') {
        break;
    }

    p = strchr(k, '=');

    if (p == NULL) {
        DtloginInfo("Malformed key \'%s\'\n", k);
        return 0;
    }

    *p = '\0'; /* end of key string */
    p++;

    if (*p != '\"') {
        DtloginInfo("Bad delimiter at \'%s\'\n", p);
        return 0;
    }

    v = p + 1; /* start of value string */

    p = strchr(v, '\"');

    if (p == NULL) {
        DtloginInfo("Missing quote after value \'%s\'\n", v);
        break;
    }

    *p = '\0'; /* end of value string */

    s = p + 1; /* start of next pair */

    DtloginInfo("Received key \"%s\" =>", k);
    DtloginInfo(" value \"%s\"\n", v);

    /* Found key & value, now process & put into dmd */
    if (strcmp(k, "EOF") == 0) {
        /* End of transmission, process & close */
        dtlogin_process(dmd);
        return 1;
    }
    else if (strcmp(k, "HOME") == 0) {
        dmd->homedir = xstrdup(v);
    }
    else if ( (strcmp(k, "UID") == 0) || (strcmp(k, "GID") == 0)
          || (strcmp(k, "G_LIST_ID") == 0) ) {
        /* Value is numeric, convert to int */
        int val;

        errno = 0;
        val = strtol(v, NULL, 10);

        if ((val == 0) && (strcmp(v, "0") != 0)) {
        /* strtol couldn't parse the results */
        DtloginInfo("Invalid number \"%s\"\n", v);
        continue;
        }

        if ( ((val == LONG_MAX) || (val == LONG_MIN))
         && (errno == ERANGE) ) {
        /* Value out of range */
        DtloginInfo("Out of range number \"%s\"\n", v);
        continue;
        }

        if (strcmp(k, "UID") == 0) {
        dmd->uid = val;
        }
        else if (strcmp(k, "GID") == 0) {
        dmd->gid = val;
        }
        else if (strcmp(k, "G_LIST_ID") == 0) {
        if (dmd->groupid_cnt < NGROUPS_UMAX) {
            dmd->groupids[dmd->groupid_cnt++] = val;
        }
        }
    }
    else {
        DtloginInfo("Unrecognized key \"%s\"\n", k);
    }
    }

    return 0;
}


static void
dtlogin_process(struct dmdata *dmd)
{
    struct project proj;
    char proj_buf[PROJECT_BUFSZ];
    struct passwd *ppasswd;
    const char *auth_file = NULL;

    auth_file = GetAuthFilename();

    if (auth_file) {
    if (chown((const char*)auth_file, dmd->uid, dmd->gid) < 0)
        DtloginError("Error in changing owner");
    }

    /* This gid dance is necessary in order to make sure
       our "saved-set-gid" is 0 so that we can regain gid
       0 when necessary for priocntl & power management.
       The first step sets rgid to the user's gid and
       makes the egid & saved-gid be 0.  The second then
       sets the egid to the users gid, but leaves the
       saved-gid as 0.  */

    if (dmd->gid != (gid_t) -1) {
    DtloginInfo("Setting gid to %d\n", dmd->gid);

    if (setregid(dmd->gid, 0) < 0)
        DtloginError("Error in setting regid");

    if (setegid(dmd->gid) < 0)
        DtloginError("Error in setting egid");
    }

    if (dmd->groupid_cnt > 0) {
    if (setgroups(dmd->groupid_cnt, dmd->groupids) < 0)
        DtloginError("Error in setting groups");
    }


    /*
     * BUG: 4462531: Set project ID for Xserver
     *               Get user name and default project.
     *               Set before the uid value is set.
     */
    if (dmd->uid != (uid_t) -1) {
    ppasswd = getpwuid(dmd->uid);

    if (ppasswd == NULL)
        DtloginError("Error in getting user name");

    if (getdefaultproj(ppasswd->pw_name, &proj,
               (void *)&proj_buf, PROJECT_BUFSZ) == NULL)
        DtloginError("Error in getting project id");

    DtloginInfo("Setting project to %s\n", proj.pj_name);

    if (setproject(proj.pj_name, ppasswd->pw_name, TASK_NORMAL) == -1)
        DtloginError("Error in setting project");

    DtloginInfo("Setting uid to %d\n", dmd->uid);
    if (setreuid(dmd->uid,dmd->uid) < 0)
        DtloginError("Error in setting uid");
    }

    if (dmd->homedir != NULL) {
    /* Allocate enough for "HOME=" + homedir + '\0' */
    char *env_str = (char *) xalloc (strlen(dmd->homedir) + 6);

    if ( env_str == NULL ) {
        DtloginError("Not enough memory to set HOME");
    } else {
        sprintf(env_str, "HOME=%s", dmd->homedir);
        DtloginInfo("Setting %s\n",env_str);

        if (putenv(env_str) < 0)
        DtloginError("Error in setting HOME");
    }

    if (chdir(dmd->homedir) < 0)
        DtloginError("Error in changing working directory");
    }

    /* Inform the kernel that a user has logged in on this VT device */
    if (xf86ConsoleFd != -1)
    ioctl(xf86ConsoleFd, VT_SETDISPLOGIN, 1);
}