On Mon, 2006-07-17 at 13:31 -0400, David Quigley wrote:
> Hello,
> I am working on the pam_namespace code a bit and while going through
> and making my changes I did a little code cleanup to make it more readable
> (atleast in my opinion). Attached is a patch that factors out some parts of
> the larger functions in pam_namespace and also moves all of the includes and
> defines into a header file.
>
Can you please break this large patch into a set of smaller patches?
That way it will be easier to review. I am ok with rearranging the code
to make it more efficient and readable. However, because we are very
close to the RHEL5 code freeze, I am nervous about the impact of a
large code change.
-Janak
> Makefile.am | 2
> pam_namespace.c | 492 +++++++++++++++++++++++++-------------------------------
> pam_namespace.h | 135 +++++++++++++++
> 3 files changed, 357 insertions(+), 272 deletions(-)
>
> diff -uprN -X dontdiff pam_namespace_orig/Makefile.am pam_namespace/Makefile.am
> --- pam_namespace_orig/Makefile.am 2006-06-28 03:22:43.000000000 -0400
> +++ pam_namespace/Makefile.am 2006-07-17 13:16:39.000000000 -0400
> @@ -32,7 +32,7 @@ endif
>
> if HAVE_UNSHARE
> securelib_LTLIBRARIES = pam_namespace.la
> -pam_namespace_la_SOURCES = pam_namespace.c md5.c md5.h
> +pam_namespace_la_SOURCES = pam_namespace.c pam_namespace.h md5.c md5.h
>
> secureconf_DATA = namespace.conf
> secureconf_SCRIPTS = namespace.init
> diff -uprN -X dontdiff pam_namespace_orig/pam_namespace.c pam_namespace/pam_namespace.c
> --- pam_namespace_orig/pam_namespace.c 2006-06-27 09:07:44.000000000 -0400
> +++ pam_namespace/pam_namespace.c 2006-07-17 13:13:41.000000000 -0400
> @@ -30,110 +30,33 @@
> * DEALINGS IN THE SOFTWARE.
> */
>
> -#if !(defined(linux))
> -#error THIS CODE IS KNOWN TO WORK ONLY ON LINUX !!!
> -#endif
> -
> -#include "config.h"
> -
> -#include <stdio.h>
> -#include <stdio_ext.h>
> -#include <unistd.h>
> -#include <string.h>
> -#include <ctype.h>
> -#include <stdlib.h>
> -#include <errno.h>
> -#include <syslog.h>
> -#include <dlfcn.h>
> -#include <stdarg.h>
> -#include <pwd.h>
> -#include <limits.h>
> -#include <sys/types.h>
> -#include <sys/stat.h>
> -#include <sys/resource.h>
> -#include <sys/mount.h>
> -#include <sys/wait.h>
> -#include <libgen.h>
> -#include <fcntl.h>
> -#include <sched.h>
> -#include "security/pam_modules.h"
> -#include "security/pam_modutil.h"
> -#include "security/pam_ext.h"
> -#include "md5.h"
> -
> -#ifdef WITH_SELINUX
> -#include <selinux/selinux.h>
> -#endif
> -
> -#ifndef CLONE_NEWNS
> -#define CLONE_NEWNS 0x00020000 /* Flag to create new namespace */
> -#endif
> +#include "pam_namespace.h"
>
> /*
> - * Module defines
> + * Copies the contents of ent into pent
> */
> -#ifndef PAM_NAMESPACE_CONFIG
> -#define PAM_NAMESPACE_CONFIG "/etc/security/namespace.conf"
> -#endif
> -
> -#ifndef NAMESPACE_INIT_SCRIPT
> -#define NAMESPACE_INIT_SCRIPT "/etc/security/namespace.init"
> -#endif
> -
> -#define PAMNS_DEBUG 0x00000100 /* Running in debug mode */
> -#define PAMNS_SELINUX_ENABLED 0x00000400 /* SELinux is enabled */
> -#define PAMNS_CTXT_BASED_INST 0x00000800 /* Context based instance needed */
> -#define PAMNS_GEN_HASH 0x00002000 /* Generate md5 hash for inst names */
> -#define PAMNS_IGN_CONFIG_ERR 0x00004000 /* Ignore format error in conf file */
> -#define PAMNS_IGN_INST_PARENT_MODE 0x00008000 /* Ignore instance parent mode */
> -
> -/*
> - * Polyinstantiation method options, based on user, security context
> - * or both
> - */
> -enum polymethod {
> - USER,
> - CONTEXT,
> - BOTH,
> -};
> -
> -/*
> - * Depending on the application using this namespace module, we
> - * may need to unmount priviously bind mounted instance directory.
> - * Applications such as login and sshd, that establish a new
> - * session unmount of instance directory is not needed. For applications
> - * such as su and newrole, that switch the identity, this module
> - * has to unmount previous instance directory first and re-mount
> - * based on the new indentity. For other trusted applications that
> - * just want to undo polyinstantiation, only unmount of previous
> - * instance directory is needed.
> - */
> -enum unmnt_op {
> - NO_UNMNT,
> - UNMNT_REMNT,
> - UNMNT_ONLY,
> -};
> -
> -/*
> - * Structure that holds information about a directory to polyinstantiate
> - */
> -struct polydir_s {
> - char dir[PATH_MAX]; /* directory to polyinstantiate */
> - char instance_prefix[PATH_MAX]; /* prefix for instance dir path name */
> - enum polymethod method; /* method used to polyinstantiate */
> - unsigned int num_uids; /* number of override uids */
> - uid_t *uid; /* list of override uids */
> - struct polydir_s *next; /* pointer to the next polydir entry */
> -};
> -
> -struct instance_data {
> - pam_handle_t *pamh; /* The pam handle for this instance */
> - struct polydir_s *polydirs_ptr; /* The linked list pointer */
> - char user[LOGIN_NAME_MAX]; /* User name */
> - uid_t uid; /* The uid of the user */
> - unsigned long flags; /* Flags for debug, selinux etc */
> -};
> +static int copy_ent(const struct polydir_s *ent, struct polydir_s *pent)
> +{
> + unsigned int i;
>
> + strcpy(pent->dir, ent->dir);
> + strcpy(pent->instance_prefix, ent->instance_prefix);
> + pent->method = ent->method;
> + pent->num_uids = ent->num_uids;
> + if (ent->num_uids) {
> + uid_t *pptr, *eptr;
> +
> + pent->uid = (uid_t *) malloc(ent->num_uids * sizeof(uid_t));
> + if (!(pent->uid)) {
> + return -1;
> + }
> + for (i = 0, pptr = pent->uid, eptr = ent->uid; i < ent->num_uids;
> + i++, eptr++, pptr++)
> + *pptr = *eptr;
> + } else
> + pent->uid = NULL;
> + return 0;
> +}
> /*
> * Adds an entry for a polyinstantiated directory to the linked list of
> * polyinstantiated directories. It is called from process_line() while
> @@ -143,7 +66,7 @@ static int add_polydir_entry(struct inst
> const struct polydir_s *ent)
> {
> struct polydir_s *pent;
> - unsigned int i;
> + int rc = 0;
>
> /*
> * Allocate an entry to hold information about a directory to
> @@ -152,27 +75,14 @@ static int add_polydir_entry(struct inst
> * directories.
> */
> pent = (struct polydir_s *) malloc(sizeof(struct polydir_s));
> - if (!pent)
> - return -1;
> -
> + if (!pent) {
> + rc = -1;
> + goto out;
> + }
> /* Make copy */
> - strcpy(pent->dir, ent->dir);
> - strcpy(pent->instance_prefix, ent->instance_prefix);
> - pent->method = ent->method;
> - pent->num_uids = ent->num_uids;
> - if (ent->num_uids) {
> - uid_t *pptr, *eptr;
> -
> - pent->uid = (uid_t *) malloc(ent->num_uids * sizeof(uid_t));
> - if (!(pent->uid)) {
> - free(pent);
> - return -1;
> - }
> - for (i = 0, pptr = pent->uid, eptr = ent->uid; i < ent->num_uids;
> - i++, eptr++, pptr++)
> - *pptr = *eptr;
> - } else
> - pent->uid = NULL;
> + rc = copy_ent(ent,pent);
> + if(rc < 0)
> + goto out_clean;
>
> /* Now attach to linked list */
> pent->next = NULL;
> @@ -186,8 +96,11 @@ static int add_polydir_entry(struct inst
> tail = tail->next;
> tail->next = pent;
> }
> -
> - return 0;
> + goto out;
> +out_clean:
> + free(pent);
> +out:
> + return rc;
> }
>
>
> @@ -515,7 +428,55 @@ static int ns_override(struct polydir_s
> return 0;
> }
>
> +#ifdef WITH_SELINUX
> +static int form_context(const struct polydir_s *polyptr,
> + security_context_t *i_context, security_context_t *origcon,
> + struct instance_data *idata)
> +{
> + int rc = PAM_SUCCESS;
> + security_context_t scon = NULL;
> + security_class_t tclass;
> +
> + /*
> + * Get the security context of the directory to polyinstantiate.
> + */
> + rc = getfilecon(polyptr->dir, origcon);
> + if (rc < 0 || *origcon == NULL) {
> + pam_syslog(idata->pamh, LOG_ERR,
> + "Error getting poly dir context, %m");
> + return PAM_SESSION_ERR;
> + }
> +
> + /*
> + * If polyinstantiating based on security context, get current
> + * process security context, get security class for directories,
> + * and ask the policy to provide security context of the
> + * polyinstantiated instance directory.
> + */
> + if ((polyptr->method == CONTEXT) || (polyptr->method == BOTH)) {
> + rc = getexeccon(&scon);
> + if (rc < 0 || scon == NULL) {
> + pam_syslog(idata->pamh, LOG_ERR,
> + "Error getting exec context, %m");
> + return PAM_SESSION_ERR;
> + }
> + tclass = string_to_security_class("dir");
> +
> + if (security_compute_member(scon, *origcon, tclass,
> + i_context) < 0) {
> + pam_syslog(idata->pamh, LOG_ERR,
> + "Error computing poly dir member context");
> + freecon(scon);
> + return PAM_SESSION_ERR;
> + } else if (idata->flags & PAMNS_DEBUG)
> + pam_syslog(idata->pamh, LOG_DEBUG,
> + "member context returned by policy %s", *i_context);
> + freecon(scon);
> + }
> + return PAM_SUCCESS;
> +}
>
> +#endif
> /*
> * poly_name returns the name of the polyinstantiated instance directory
> * based on the method used for polyinstantiation (user, context or both)
> @@ -532,49 +493,10 @@ static int poly_name(const struct polydi
> struct instance_data *idata)
> #endif
> {
> -#ifdef WITH_SELINUX
> - security_context_t scon = NULL;
> - security_class_t tclass;
> -#endif
> int rc;
>
> # ifdef WITH_SELINUX
> - /*
> - * Get the security context of the directory to polyinstantiate.
> - */
> - rc = getfilecon(polyptr->dir, origcon);
> - if (rc < 0 || *origcon == NULL) {
> - pam_syslog(idata->pamh, LOG_ERR,
> - "Error getting poly dir context, %m");
> - return PAM_SESSION_ERR;
> - }
> -
> - /*
> - * If polyinstantiating based on security context, get current
> - * process security context, get security class for directories,
> - * and ask the policy to provide security context of the
> - * polyinstantiated instance directory.
> - */
> - if ((polyptr->method == CONTEXT) || (polyptr->method == BOTH)) {
> - rc = getexeccon(&scon);
> - if (rc < 0 || scon == NULL) {
> - pam_syslog(idata->pamh, LOG_ERR,
> - "Error getting exec context, %m");
> - return PAM_SESSION_ERR;
> - }
> - tclass = string_to_security_class("dir");
> -
> - if (security_compute_member(scon, *origcon, tclass,
> - i_context) < 0) {
> - pam_syslog(idata->pamh, LOG_ERR,
> - "Error computing poly dir member context");
> - freecon(scon);
> - return PAM_SESSION_ERR;
> - } else if (idata->flags & PAMNS_DEBUG)
> - pam_syslog(idata->pamh, LOG_DEBUG,
> - "member context returned by policy %s", *i_context);
> - freecon(scon);
> - }
> + rc = form_context(polyptr, i_context, origcon, idata);
> #endif
> rc = PAM_SUCCESS;
>
> @@ -618,6 +540,122 @@ static int poly_name(const struct polydi
> return rc;
> }
>
> +static int check_inst_parent(char *ipath, struct instance_data *idata)
> +{
> + struct stat instpbuf;
> + char *inst_parent, *trailing_slash;
> + /*
> + * stat the instance parent path to make sure it exists
> + * and is a directory. Check that its mode is 000 (unless the
> + * admin explicitly instructs to ignore the instance parent
> + * mode by the "ignore_instance_parent_mode" argument).
> + */
> + inst_parent = (char *) malloc(strlen(ipath)+1);
> + if (!inst_parent) {
> + pam_syslog(idata->pamh, LOG_ERR, "Error allocating pathname string");
> + return PAM_SESSION_ERR;
> + }
> +
> + strcpy(inst_parent, ipath);
> + trailing_slash = strrchr(inst_parent, '/');
> + if (trailing_slash)
> + *trailing_slash = '\0';
> +
> + if (stat(inst_parent, &instpbuf) < 0) {
> + pam_syslog(idata->pamh, LOG_ERR, "Error stating %s, %m", inst_parent);
> + free(inst_parent);
> + return PAM_SESSION_ERR;
> + }
> +
> + /*
> + * Make sure we are dealing with a directory
> + */
> + if (!S_ISDIR(instpbuf.st_mode)) {
> + pam_syslog(idata->pamh, LOG_ERR, "Instance parent %s is not a dir",
> + inst_parent);
> + free(inst_parent);
> + return PAM_SESSION_ERR;
> + }
> +
> + if ((idata->flags & PAMNS_IGN_INST_PARENT_MODE) == 0) {
> + if (instpbuf.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) {
> + pam_syslog(idata->pamh, LOG_ERR, "Mode of inst parent %s not 000",
> + inst_parent);
> + free(inst_parent);
> + return PAM_SESSION_ERR;
> + }
> + }
> + free(inst_parent);
> + return PAM_SUCCESS;
> +}
> +
> +/*
> +* Check to see if there is a namespace initialization script in
> +* the /etc/security directory. If such a script exists
> +* execute it and pass directory to polyinstantiate and instance
> +* directory as arguments.
> +*/
> +static int inst_init(const struct polydir_s *polyptr, char *ipath,
> + struct instance_data *idata)
> +{
> + pid_t rc, pid;
> + sighandler_t osighand = NULL;
> + int status;
> +
> + osighand = signal(SIGCHLD, SIG_DFL);
> + if (osighand == SIG_ERR) {
> + pam_syslog(idata->pamh, LOG_ERR, "Cannot set signal value");
> + rc = PAM_SESSION_ERR;
> + goto out;
> + }
> +
> + if (access(NAMESPACE_INIT_SCRIPT, F_OK) == 0) {
> + if (access(NAMESPACE_INIT_SCRIPT, X_OK) < 0) {
> + if (idata->flags & PAMNS_DEBUG)
> + pam_syslog(idata->pamh, LOG_ERR,
> + "Namespace init script not executable");
> + rc = PAM_SESSION_ERR;
> + goto out;
> + } else {
> + pid = fork();
> + if (pid == 0) {
> +#ifdef WITH_SELINUX
> + if (idata->flags & PAMNS_SELINUX_ENABLED) {
> + if (setexeccon(NULL) < 0)
> + exit(1);
> + }
> +#endif
> + if (execl(NAMESPACE_INIT_SCRIPT, NAMESPACE_INIT_SCRIPT,
> + polyptr->dir, ipath, (char *)NULL) < 0)
> + exit(1);
> + } else if (pid > 0) {
> + while (((rc = waitpid(pid, &status, 0)) == (pid_t)-1) &&
> + (errno == EINTR));
> + if (rc == (pid_t)-1) {
> + pam_syslog(idata->pamh, LOG_ERR, "waitpid failed- %m");
> + rc = PAM_SESSION_ERR;
> + goto out;
> + }
> + if (!WIFEXITED(status) || WIFSIGNALED(status) > 0) {
> + pam_syslog(idata->pamh, LOG_ERR,
> + "Error initializing instance");
> + rc = PAM_SESSION_ERR;
> + goto out;
> + }
> + } else if (pid < 0) {
> + pam_syslog(idata->pamh, LOG_ERR,
> + "Cannot fork to run namespace init script, %m");
> + rc = PAM_SESSION_ERR;
> + goto out;
> + }
> + }
> + }
> + rc = PAM_SUCCESS;
> +out:
> + (void) signal(SIGCHLD, osighand);
> +
> + return rc;
> +}
>
> /*
> * Create polyinstantiated instance directory (ipath).
> @@ -631,16 +669,14 @@ static int create_dirs(const struct poly
> struct instance_data *idata)
> #endif
> {
> - struct stat statbuf, newstatbuf, instpbuf;
> - int fd, status;
> - char *inst_parent, *trailing_slash;
> - pid_t rc, pid;
> - sighandler_t osighand = NULL;
> + struct stat statbuf, newstatbuf;
> + int rc, fd;
>
> /*
> * stat the directory to polyinstantiate, so its owner-group-mode
> * can be propagated to instance directory
> */
> + rc = PAM_SUCCESS;
> if (stat(polyptr->dir, &statbuf) < 0) {
> pam_syslog(idata->pamh, LOG_ERR, "Error stating %s, %m",
> polyptr->dir);
> @@ -655,49 +691,12 @@ static int create_dirs(const struct poly
> polyptr->dir);
> return PAM_SESSION_ERR;
> }
> -
> - /*
> - * stat the instance parent path to make sure it exists
> - * and is a directory. Check that its mode is 000 (unless the
> - * admin explicitly instructs to ignore the instance parent
> - * mode by the "ignore_instance_parent_mode" argument).
> - */
> - inst_parent = (char *) malloc(strlen(ipath)+1);
> - if (!inst_parent) {
> - pam_syslog(idata->pamh, LOG_ERR, "Error allocating pathname string");
> - return PAM_SESSION_ERR;
> - }
> -
> - strcpy(inst_parent, ipath);
> - trailing_slash = strrchr(inst_parent, '/');
> - if (trailing_slash)
> - *trailing_slash = '\0';
> -
> - if (stat(inst_parent, &instpbuf) < 0) {
> - pam_syslog(idata->pamh, LOG_ERR, "Error stating %s, %m", inst_parent);
> - free(inst_parent);
> - return PAM_SESSION_ERR;
> - }
> -
> - /*
> - * Make sure we are dealing with a directory
> - */
> - if (!S_ISDIR(instpbuf.st_mode)) {
> - pam_syslog(idata->pamh, LOG_ERR, "Instance parent %s is not a dir",
> - inst_parent);
> - free(inst_parent);
> - return PAM_SESSION_ERR;
> - }
> -
> - if ((idata->flags & PAMNS_IGN_INST_PARENT_MODE) == 0) {
> - if (instpbuf.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) {
> - pam_syslog(idata->pamh, LOG_ERR, "Mode of inst parent %s not 000",
> - inst_parent);
> - free(inst_parent);
> - return PAM_SESSION_ERR;
> - }
> - }
> - free(inst_parent);
> +
> + /*
> + * Check to make sure instance parent is valid.
> + */
> + if (check_inst_parent(ipath, idata))
> + return PAM_SESSION_ERR;
>
> /*
> * Create instance directory and set its security context to the context
> @@ -779,56 +778,8 @@ static int create_dirs(const struct poly
> */
>
> inst_init:
> - osighand = signal(SIGCHLD, SIG_DFL);
> - if (osighand == SIG_ERR) {
> - pam_syslog(idata->pamh, LOG_ERR, "Cannot set signal value");
> - return PAM_SESSION_ERR;
> - }
> -
> - if (access(NAMESPACE_INIT_SCRIPT, F_OK) == 0) {
> - if (access(NAMESPACE_INIT_SCRIPT, X_OK) < 0) {
> - if (idata->flags & PAMNS_DEBUG)
> - pam_syslog(idata->pamh, LOG_ERR,
> - "Namespace init script not executable");
> - (void) signal(SIGCHLD, osighand);
> - return PAM_SESSION_ERR;
> - } else {
> - pid = fork();
> - if (pid == 0) {
> -#ifdef WITH_SELINUX
> - if (idata->flags & PAMNS_SELINUX_ENABLED) {
> - if (setexeccon(NULL) < 0)
> - exit(1);
> - }
> -#endif
> - if (execl(NAMESPACE_INIT_SCRIPT, NAMESPACE_INIT_SCRIPT,
> - polyptr->dir, ipath, (char *)NULL) < 0)
> - exit(1);
> - } else if (pid > 0) {
> - while (((rc = waitpid(pid, &status, 0)) == (pid_t)-1) &&
> - (errno == EINTR));
> - if (rc == (pid_t)-1) {
> - pam_syslog(idata->pamh, LOG_ERR, "waitpid failed- %m");
> - (void) signal(SIGCHLD, osighand);
> - return PAM_SESSION_ERR;
> - }
> - if (!WIFEXITED(status) || WIFSIGNALED(status) > 0) {
> - pam_syslog(idata->pamh, LOG_ERR,
> - "Error initializing instance");
> - (void) signal(SIGCHLD, osighand);
> - return PAM_SESSION_ERR;
> - }
> - } else if (pid < 0) {
> - pam_syslog(idata->pamh, LOG_ERR,
> - "Cannot fork to run namespace init script, %m");
> - (void) signal(SIGCHLD, osighand);
> - return PAM_SESSION_ERR;
> - }
> - }
> - }
> -
> - (void) signal(SIGCHLD, osighand);
> - return PAM_SUCCESS;
> + rc = inst_init(polyptr, ipath, idata);
> + return rc;
> }
>
>
> @@ -1173,16 +1124,16 @@ static int orig_namespace(struct instanc
> */
> static int ctxt_based_inst_needed(void)
> {
> - security_context_t scon = NULL;
> - int rc = 0;
> + security_context_t scon = NULL;
> + int rc = 0;
>
> - rc = getexeccon(&scon);
> - if (rc < 0 || scon == NULL)
> - return 0;
> - else {
> - freecon(scon);
> - return 1;
> - }
> + rc = getexeccon(&scon);
> + if (rc < 0 || scon == NULL)
> + return 0;
> + else {
> + freecon(scon);
> + return 1;
> + }
> }
> #endif
>
> @@ -1285,7 +1236,6 @@ PAM_EXTERN int pam_sm_open_session(pam_h
> return retval;
> }
>
> -
> /*
> * Entry point from pam_close_session call.
> */
> diff -uprN -X dontdiff pam_namespace_orig/pam_namespace.h pam_namespace/pam_namespace.h
> --- pam_namespace_orig/pam_namespace.h 1969-12-31 19:00:00.000000000 -0500
> +++ pam_namespace/pam_namespace.h 2006-07-17 13:11:36.000000000 -0400
> @@ -0,0 +1,135 @@
> +/******************************************************************************
> + * A module for Linux-PAM that will set the default namespace after
> + * establishing a session via PAM.
> + *
> + * (C) Copyright IBM Corporation 2005
> + * (C) Copyright Red Hat 2006
> + * All Rights Reserved.
> + *
> + * Written by: Janak Desai <janak@xxxxxxxxxx>
> + * With Revisions by: Steve Grubb <sgrubb@xxxxxxxxxx>
> + * Derived from a namespace setup patch by Chad Sellers <cdselle@xxxxxxxxxxxxx>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a
> + * copy of this software and associated documentation files (the "Software"),
> + * to deal in the Software without restriction, including without limitation
> + * on the rights to use, copy, modify, merge, publish, distribute, sub
> + * license, and/or sell copies of the Software, and to permit persons to whom
> + * the Software is furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice (including the next
> + * paragraph) shall be included in all copies or substantial portions of the
> + * Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
> + * IBM AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
> + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
> + * DEALINGS IN THE SOFTWARE.
> + */
> +
> +#if !(defined(linux))
> +#error THIS CODE IS KNOWN TO WORK ONLY ON LINUX !!!
> +#endif
> +
> +#include "config.h"
> +
> +#include <stdio.h>
> +#include <stdio_ext.h>
> +#include <unistd.h>
> +#include <string.h>
> +#include <ctype.h>
> +#include <stdlib.h>
> +#include <errno.h>
> +#include <syslog.h>
> +#include <dlfcn.h>
> +#include <stdarg.h>
> +#include <pwd.h>
> +#include <limits.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <sys/resource.h>
> +#include <sys/mount.h>
> +#include <sys/wait.h>
> +#include <libgen.h>
> +#include <fcntl.h>
> +#include <sched.h>
> +#include "security/pam_modules.h"
> +#include "security/pam_modutil.h"
> +#include "security/pam_ext.h"
> +#include "md5.h"
> +
> +#ifdef WITH_SELINUX
> +#include <selinux/selinux.h>
> +#endif
> +
> +#ifndef CLONE_NEWNS
> +#define CLONE_NEWNS 0x00020000 /* Flag to create new namespace */
> +#endif
> +
> +/*
> + * Module defines
> + */
> +#ifndef PAM_NAMESPACE_CONFIG
> +#define PAM_NAMESPACE_CONFIG "/etc/security/namespace.conf"
> +#endif
> +
> +#ifndef NAMESPACE_INIT_SCRIPT
> +#define NAMESPACE_INIT_SCRIPT "/etc/security/namespace.init"
> +#endif
> +
> +#define PAMNS_DEBUG 0x00000100 /* Running in debug mode */
> +#define PAMNS_SELINUX_ENABLED 0x00000400 /* SELinux is enabled */
> +#define PAMNS_CTXT_BASED_INST 0x00000800 /* Context based instance needed */
> +#define PAMNS_GEN_HASH 0x00002000 /* Generate md5 hash for inst names */
> +#define PAMNS_IGN_CONFIG_ERR 0x00004000 /* Ignore format error in conf file */
> +#define PAMNS_IGN_INST_PARENT_MODE 0x00008000 /* Ignore instance parent mode */
> +
> +/*
> + * Polyinstantiation method options, based on user, security context
> + * or both
> + */
> +enum polymethod {
> + USER,
> + CONTEXT,
> + BOTH,
> +};
> +
> +/*
> + * Depending on the application using this namespace module, we
> + * may need to unmount priviously bind mounted instance directory.
> + * Applications such as login and sshd, that establish a new
> + * session unmount of instance directory is not needed. For applications
> + * such as su and newrole, that switch the identity, this module
> + * has to unmount previous instance directory first and re-mount
> + * based on the new indentity. For other trusted applications that
> + * just want to undo polyinstantiation, only unmount of previous
> + * instance directory is needed.
> + */
> +enum unmnt_op {
> + NO_UNMNT,
> + UNMNT_REMNT,
> + UNMNT_ONLY,
> +};
> +
> +/*
> + * Structure that holds information about a directory to polyinstantiate
> + */
> +struct polydir_s {
> + char dir[PATH_MAX]; /* directory to polyinstantiate */
> + char instance_prefix[PATH_MAX]; /* prefix for instance dir path name */
> + enum polymethod method; /* method used to polyinstantiate */
> + unsigned int num_uids; /* number of override uids */
> + uid_t *uid; /* list of override uids */
> + struct polydir_s *next; /* pointer to the next polydir entry */
> +};
> +
> +struct instance_data {
> + pam_handle_t *pamh; /* The pam handle for this instance */
> + struct polydir_s *polydirs_ptr; /* The linked list pointer */
> + char user[LOGIN_NAME_MAX]; /* User name */
> + uid_t uid; /* The uid of the user */
> + unsigned long flags; /* Flags for debug, selinux etc */
> +};
>
>
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