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authorTomas Mraz <tm@t8m.info>2009-01-19 09:09:15 +0000
committerTomas Mraz <tm@t8m.info>2009-01-19 09:09:15 +0000
commit7b14630ef39e71f603aeca0c47edf2f384717176 (patch)
tree68751e81ff14c1531c4335d3e934da8c43deb574 /modules/pam_mkhomedir/pam_mkhomedir.c
parent5cfa0b95c4f2a943a484522cb7882d8e13866a94 (diff)
Relevant BUGIDs: rhbz#476784
Purpose of commit: new feature Commit summary: --------------- 2009-01-19 Tomas Mraz <t8m@centrum.cz> * modules/pam_mkhomedir/Makefile.am: Add mkhomedir_helper. * modules/pam_mkhomedir/mkhomedir_helper.8.xml: New file. Manual page for mkhomedir_helper. * modules/pam_mkhomedir/mkhomedir_helper.c: New file. Source for mkhomedir_helper. Most of the code moved from pam_mkhomedir.c. * modules/pam_mkhomedir/pam_mkhomedir.c (_pam_parse): Do not convert umask to integer. (rec_mkdir): Moved to mkhomedir_helper.c. (create_homedir): Just exec the helper. (pam_sm_open_session): Improve logging.
Diffstat (limited to 'modules/pam_mkhomedir/pam_mkhomedir.c')
-rw-r--r--modules/pam_mkhomedir/pam_mkhomedir.c421
1 files changed, 81 insertions, 340 deletions
diff --git a/modules/pam_mkhomedir/pam_mkhomedir.c b/modules/pam_mkhomedir/pam_mkhomedir.c
index 44b092c1..a0c389c5 100644
--- a/modules/pam_mkhomedir/pam_mkhomedir.c
+++ b/modules/pam_mkhomedir/pam_mkhomedir.c
@@ -22,6 +22,7 @@
password required pam_unix.so
Released under the GNU LGPL version 2 or later
+ Copyright (c) Red Hat, Inc. 2009
Originally written by Jason Gunthorpe <jgg@debian.org> Feb 1999
Structure taken from pam_lastlogin by Andrew Morgan
<morgan@parc.power.net> 1996
@@ -29,18 +30,19 @@
#include "config.h"
-#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
-#include <fcntl.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
#include <unistd.h>
#include <pwd.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
-#include <dirent.h>
#include <syslog.h>
+#include <signal.h>
/*
* here, we make a definition for the externally accessible function
@@ -56,12 +58,13 @@
#include <security/pam_modutil.h>
#include <security/pam_ext.h>
+#define MAX_FD_NO 10000
/* argument parsing */
#define MKHOMEDIR_DEBUG 020 /* be verbose about things */
#define MKHOMEDIR_QUIET 040 /* keep quiet about things */
-static unsigned int UMask = 0022;
+static char UMask[16] = "0022";
static char SkelDir[BUFSIZ] = "/etc/skel"; /* THIS MODULE IS NOT THREAD SAFE */
static int
@@ -81,7 +84,8 @@ _pam_parse (const pam_handle_t *pamh, int flags, int argc, const char **argv)
} else if (!strcmp(*argv, "debug")) {
ctrl |= MKHOMEDIR_DEBUG;
} else if (!strncmp(*argv,"umask=",6)) {
- UMask = strtol(*argv+6,0,0);
+ strncpy(SkelDir,*argv+6,sizeof(UMask));
+ UMask[sizeof(UMask)-1] = '\0';
} else if (!strncmp(*argv,"skel=",5)) {
strncpy(SkelDir,*argv+5,sizeof(SkelDir));
SkelDir[sizeof(SkelDir)-1] = '\0';
@@ -94,357 +98,88 @@ _pam_parse (const pam_handle_t *pamh, int flags, int argc, const char **argv)
return ctrl;
}
-static int
-rec_mkdir (const char *dir, mode_t mode)
-{
- char *cp;
- char *parent = strdup (dir);
-
- if (parent == NULL)
- return 1;
-
- cp = strrchr (parent, '/');
-
- if (cp != NULL && cp != parent)
- {
- struct stat st;
-
- *cp++ = '\0';
- if (stat (parent, &st) == -1 && errno == ENOENT)
- if (rec_mkdir (parent, mode) != 0)
- {
- free (parent);
- return 1;
- }
- }
-
- free (parent);
-
- if (mkdir (dir, mode) != 0 && errno != EEXIST)
- return 1;
-
- return 0;
-}
-
/* Do the actual work of creating a home dir */
static int
-create_homedir (pam_handle_t * pamh, int ctrl,
- const struct passwd *pwd,
- const char *source, const char *dest)
+create_homedir (pam_handle_t *pamh, int ctrl,
+ const struct passwd *pwd)
{
- char remark[BUFSIZ];
- DIR *D;
- struct dirent *Dir;
- int retval = PAM_AUTH_ERR;
+ int retval, child;
+ void (*sighandler)(int) = NULL;
/* Mention what is happening, if the notification fails that is OK */
- if ((ctrl & MKHOMEDIR_QUIET) != MKHOMEDIR_QUIET)
- pam_info(pamh, _("Creating directory '%s'."), dest);
-
- /* Create the new directory */
- if (rec_mkdir (dest,0755) != 0)
- {
- pam_error(pamh, _("Unable to create directory %s: %m"), dest);
- pam_syslog(pamh, LOG_ERR, "unable to create directory %s: %m", dest);
- return PAM_PERM_DENIED;
- }
-
- /* See if we need to copy the skel dir over. */
- if ((source == NULL) || (strlen(source) == 0))
- {
- retval = PAM_SUCCESS;
- goto go_out;
- }
-
- /* Scan the directory */
- D = opendir (source);
- if (D == 0)
- {
- pam_syslog(pamh, LOG_DEBUG, "unable to read directory %s: %m", source);
- retval = PAM_PERM_DENIED;
- goto go_out;
- }
-
- for (Dir = readdir(D); Dir != 0; Dir = readdir(D))
- {
- int SrcFd;
- int DestFd;
- int Res;
- struct stat St;
-#ifndef PATH_MAX
- char *newsource = NULL, *newdest = NULL;
- /* track length of buffers */
- int nslen = 0, ndlen = 0;
- int slen = strlen(source), dlen = strlen(dest);
-#else
- char newsource[PATH_MAX], newdest[PATH_MAX];
-#endif
-
- /* Skip some files.. */
- if (strcmp(Dir->d_name,".") == 0 ||
- strcmp(Dir->d_name,"..") == 0)
- continue;
-
- /* Determine what kind of file it is. */
-#ifndef PATH_MAX
- nslen = slen + strlen(Dir->d_name) + 2;
-
- if (nslen <= 0)
- {
- retval = PAM_BUF_ERR;
- goto go_out;
- }
-
- if ((newsource = malloc (nslen)) == NULL)
- {
- retval = PAM_BUF_ERR;
- goto go_out;
- }
+ if (!(ctrl & MKHOMEDIR_QUIET))
+ pam_info(pamh, _("Creating directory '%s'."), pwd->pw_dir);
- sprintf(newsource, "%s/%s", source, Dir->d_name);
-#else
- snprintf(newsource,sizeof(newsource),"%s/%s",source,Dir->d_name);
-#endif
- if (lstat(newsource,&St) != 0)
-#ifndef PATH_MAX
- {
- free(newsource);
- newsource = NULL;
- continue;
- }
-#else
- continue;
-#endif
+ D(("called."));
+ /*
+ * This code arranges that the demise of the child does not cause
+ * the application to receive a signal it is not expecting - which
+ * may kill the application or worse.
+ */
+ sighandler = signal(SIGCHLD, SIG_DFL);
- /* We'll need the new file's name. */
-#ifndef PATH_MAX
- ndlen = dlen + strlen(Dir->d_name)+2;
+ if (ctrl & MKHOMEDIR_DEBUG) {
+ pam_syslog(pamh, LOG_DEBUG, "Executing mkhomedir_helper.");
+ }
- if (ndlen <= 0)
- {
- retval = PAM_BUF_ERR;
- goto go_out;
+ /* fork */
+ child = fork();
+ if (child == 0) {
+ int i;
+ struct rlimit rlim;
+ static char *envp[] = { NULL };
+ char *args[] = { NULL, NULL, NULL, NULL, NULL };
+
+ if (getrlimit(RLIMIT_NOFILE, &rlim)==0) {
+ if (rlim.rlim_max >= MAX_FD_NO)
+ rlim.rlim_max = MAX_FD_NO;
+ for (i=0; i < (int)rlim.rlim_max; i++) {
+ close(i);
+ }
}
- if ((newdest = malloc(ndlen)) == NULL)
- {
- free (newsource);
- retval = PAM_BUF_ERR;
- goto go_out;
+ /* exec the mkhomedir helper */
+ args[0] = x_strdup(MKHOMEDIR_HELPER);
+ args[1] = pwd->pw_name;
+ args[2] = UMask;
+ args[3] = SkelDir;
+
+ execve(MKHOMEDIR_HELPER, args, envp);
+
+ /* should not get here: exit with error */
+ D(("helper binary is not available"));
+ exit(PAM_SYSTEM_ERR);
+ } else if (child > 0) {
+ int rc;
+ while ((rc=waitpid(child, &retval, 0)) < 0 && errno == EINTR);
+ if (rc < 0) {
+ pam_syslog(pamh, LOG_ERR, "waitpid failed: %m");
+ retval = PAM_SYSTEM_ERR;
+ } else {
+ retval = WEXITSTATUS(retval);
}
-
- sprintf (newdest, "%s/%s", dest, Dir->d_name);
-#else
- snprintf (newdest,sizeof (newdest),"%s/%s",dest,Dir->d_name);
-#endif
-
- /* If it's a directory, recurse. */
- if (S_ISDIR(St.st_mode))
- {
- retval = create_homedir (pamh, ctrl, pwd, newsource, newdest);
-
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
-
- if (retval != PAM_SUCCESS)
- {
- closedir(D);
- goto go_out;
- }
- continue;
- }
-
- /* If it's a symlink, create a new link. */
- if (S_ISLNK(St.st_mode))
- {
- int pointedlen = 0;
-#ifndef PATH_MAX
- char *pointed = NULL;
- {
- int size = 100;
-
- while (1) {
- pointed = (char *) malloc(size);
- if ( ! pointed ) {
- free(newsource);
- free(newdest);
- return PAM_BUF_ERR;
- }
- pointedlen = readlink (newsource, pointed, size);
- if ( pointedlen < 0 ) break;
- if ( pointedlen < size ) break;
- free (pointed);
- size *= 2;
- }
- }
- if ( pointedlen < 0 )
- free(pointed);
- else
- pointed[pointedlen] = 0;
-#else
- char pointed[PATH_MAX];
- memset(pointed, 0, sizeof(pointed));
-
- pointedlen = readlink(newsource, pointed, sizeof(pointed) - 1);
-#endif
-
- if ( pointedlen >= 0 ) {
- if(symlink(pointed, newdest) == 0)
- {
- if (lchown(newdest,pwd->pw_uid,pwd->pw_gid) != 0)
- {
- pam_syslog(pamh, LOG_DEBUG,
- "unable to change perms on link %s: %m", newdest);
- closedir(D);
-#ifndef PATH_MAX
- free(pointed);
- free(newsource);
- free(newdest);
-#endif
- return PAM_PERM_DENIED;
- }
- }
-#ifndef PATH_MAX
- free(pointed);
-#endif
- }
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
- continue;
- }
-
- /* If it's not a regular file, it's probably not a good idea to create
- * the new device node, FIFO, or whatever it is. */
- if (!S_ISREG(St.st_mode))
- {
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
- continue;
- }
-
- /* Open the source file */
- if ((SrcFd = open(newsource,O_RDONLY)) < 0 || fstat(SrcFd,&St) != 0)
- {
- pam_syslog(pamh, LOG_DEBUG,
- "unable to open src file %s: %m", newsource);
- closedir(D);
-
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
-
- return PAM_PERM_DENIED;
- }
- if (stat(newsource,&St) != 0)
- {
- pam_syslog(pamh, LOG_DEBUG, "unable to stat src file %s: %m",
- newsource);
- close(SrcFd);
- closedir(D);
-
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
-
- return PAM_PERM_DENIED;
- }
-
- /* Open the dest file */
- if ((DestFd = open(newdest,O_WRONLY | O_TRUNC | O_CREAT,0600)) < 0)
- {
- pam_syslog(pamh, LOG_DEBUG,
- "unable to open dest file %s: %m", newdest);
- close(SrcFd);
- closedir(D);
-
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
- return PAM_PERM_DENIED;
- }
-
- /* Set the proper ownership and permissions for the module. We make
- the file a+w and then mask it with the set mask. This preseves
- execute bits */
- if (fchmod(DestFd,(St.st_mode | 0222) & (~UMask)) != 0 ||
- fchown(DestFd,pwd->pw_uid,pwd->pw_gid) != 0)
- {
- pam_syslog(pamh, LOG_DEBUG,
- "unable to change perms on copy %s: %m", newdest);
- close(SrcFd);
- close(DestFd);
- closedir(D);
-
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
-
- return PAM_PERM_DENIED;
- }
-
- /* Copy the file */
- do
- {
- Res = pam_modutil_read(SrcFd,remark,sizeof(remark));
-
- if (Res == 0)
- continue;
-
- if (Res > 0) {
- if (pam_modutil_write(DestFd,remark,Res) == Res)
- continue;
- }
-
- /* If we get here, pam_modutil_read returned a -1 or
- pam_modutil_write returned something unexpected. */
- pam_syslog(pamh, LOG_DEBUG, "unable to perform IO: %m");
- close(SrcFd);
- close(DestFd);
- closedir(D);
-
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
-
- return PAM_PERM_DENIED;
- }
- while (Res != 0);
- close(SrcFd);
- close(DestFd);
-
-#ifndef PATH_MAX
- free(newsource); newsource = NULL;
- free(newdest); newdest = NULL;
-#endif
-
+ } else {
+ D(("fork failed"));
+ pam_syslog(pamh, LOG_ERR, "fork failed: %m");
+ retval = PAM_SYSTEM_ERR;
}
- closedir(D);
- retval = PAM_SUCCESS;
+ if (sighandler != SIG_ERR) {
+ (void) signal(SIGCHLD, sighandler); /* restore old signal handler */
+ }
- go_out:
+ if (ctrl & MKHOMEDIR_DEBUG) {
+ pam_syslog(pamh, LOG_DEBUG, "mkhomedir_helper returned %d", retval);
+ }
- if (chmod(dest,0777 & (~UMask)) != 0 ||
- chown(dest,pwd->pw_uid,pwd->pw_gid) != 0)
- {
- pam_syslog(pamh, LOG_DEBUG,
- "unable to change perms on directory %s: %m", dest);
- return PAM_PERM_DENIED;
+ if (retval != PAM_SUCCESS && !(ctrl & MKHOMEDIR_QUIET)) {
+ pam_error(pamh, _("Unable to create and initialize directory '%s'."),
+ pwd->pw_dir);
}
+ D(("returning %d", retval));
return retval;
}
@@ -466,7 +201,7 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc,
retval = pam_get_item(pamh, PAM_USER, &user);
if (retval != PAM_SUCCESS || user == NULL || *(const char *)user == '\0')
{
- pam_syslog(pamh, LOG_NOTICE, "user unknown");
+ pam_syslog(pamh, LOG_NOTICE, "Cannot obtain the user name.");
return PAM_USER_UNKNOWN;
}
@@ -474,16 +209,22 @@ pam_sm_open_session (pam_handle_t *pamh, int flags, int argc,
pwd = pam_modutil_getpwnam (pamh, user);
if (pwd == NULL)
{
+ pam_syslog(pamh, LOG_NOTICE, "User unknown.");
D(("couldn't identify user %s", user));
return PAM_CRED_INSUFFICIENT;
}
/* Stat the home directory, if something exists then we assume it is
correct and return a success*/
- if (stat(pwd->pw_dir,&St) == 0)
+ if (stat(pwd->pw_dir, &St) == 0) {
+ if (ctrl & MKHOMEDIR_DEBUG) {
+ pam_syslog(pamh, LOG_DEBUG, "Home directory %s already exists.",
+ pwd->pw_dir);
+ }
return PAM_SUCCESS;
+ }
- return create_homedir(pamh,ctrl,pwd,SkelDir,pwd->pw_dir);
+ return create_homedir(pamh, ctrl, pwd);
}
/* Ignore */