diff options
Diffstat (limited to 'modules/pam_mkhomedir/pam_mkhomedir.c')
-rw-r--r-- | modules/pam_mkhomedir/pam_mkhomedir.c | 455 |
1 files changed, 101 insertions, 354 deletions
diff --git a/modules/pam_mkhomedir/pam_mkhomedir.c b/modules/pam_mkhomedir/pam_mkhomedir.c index 44b092c1..dfc4979e 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 @@ -56,395 +58,133 @@ #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 SkelDir[BUFSIZ] = "/etc/skel"; /* THIS MODULE IS NOT THREAD SAFE */ +struct options_t { + int ctrl; + const char *umask; + const char *skeldir; +}; +typedef struct options_t options_t; -static int -_pam_parse (const pam_handle_t *pamh, int flags, int argc, const char **argv) +static void +_pam_parse (const pam_handle_t *pamh, int flags, int argc, const char **argv, + options_t *opt) { - int ctrl = 0; + opt->ctrl = 0; + opt->umask = "0022"; + opt->skeldir = "/etc/skel"; /* does the appliction require quiet? */ if ((flags & PAM_SILENT) == PAM_SILENT) - ctrl |= MKHOMEDIR_QUIET; + opt->ctrl |= MKHOMEDIR_QUIET; /* step through arguments */ for (; argc-- > 0; ++argv) { if (!strcmp(*argv, "silent")) { - ctrl |= MKHOMEDIR_QUIET; + opt->ctrl |= MKHOMEDIR_QUIET; } else if (!strcmp(*argv, "debug")) { - ctrl |= MKHOMEDIR_DEBUG; + opt->ctrl |= MKHOMEDIR_DEBUG; } else if (!strncmp(*argv,"umask=",6)) { - UMask = strtol(*argv+6,0,0); + opt->umask = *argv+6; } else if (!strncmp(*argv,"skel=",5)) { - strncpy(SkelDir,*argv+5,sizeof(SkelDir)); - SkelDir[sizeof(SkelDir)-1] = '\0'; + opt->skeldir = *argv+5; } else { pam_syslog(pamh, LOG_ERR, "unknown option: %s", *argv); } } - - D(("ctrl = %o", ctrl)); - 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, options_t *opt, + const struct passwd *pwd) { - char remark[BUFSIZ]; - DIR *D; - struct dirent *Dir; - int retval = PAM_AUTH_ERR; + int retval, child; + struct sigaction newsa, oldsa; /* Mention what is happening, if the notification fails that is OK */ - if ((ctrl & MKHOMEDIR_QUIET) != MKHOMEDIR_QUIET) - pam_info(pamh, _("Creating directory '%s'."), dest); + if (!(opt->ctrl & MKHOMEDIR_QUIET)) + pam_info(pamh, _("Creating directory '%s'."), pwd->pw_dir); - /* 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; - } + D(("called.")); - /* 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; - } + /* + * 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. + */ + memset(&newsa, '\0', sizeof(newsa)); + newsa.sa_handler = SIG_DFL; + sigaction(SIGCHLD, &newsa, &oldsa); - 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; - } - - 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 - - - /* We'll need the new file's name. */ -#ifndef PATH_MAX - ndlen = dlen + strlen(Dir->d_name)+2; + if (opt->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] = x_strdup(opt->umask); + args[3] = x_strdup(opt->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 if (!WIFEXITED(retval)) { + pam_syslog(pamh, LOG_ERR, "mkhomedir_helper abnormal exit: %d", retval); + 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; + sigaction(SIGCHLD, &oldsa, NULL); /* restore old signal handler */ - go_out: + if (opt->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 && !(opt->ctrl & MKHOMEDIR_QUIET)) { + pam_error(pamh, _("Unable to create and initialize directory '%s'."), + pwd->pw_dir); } + D(("returning %d", retval)); return retval; } @@ -454,19 +194,20 @@ PAM_EXTERN int pam_sm_open_session (pam_handle_t *pamh, int flags, int argc, const char **argv) { - int retval, ctrl; + int retval; + options_t opt; const void *user; const struct passwd *pwd; struct stat St; /* Parse the flag values */ - ctrl = _pam_parse(pamh, flags, argc, argv); + _pam_parse(pamh, flags, argc, argv, &opt); /* Determine the user name so we can get the home directory */ 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 +215,22 @@ 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 (opt.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, &opt, pwd); } /* Ignore */ |