diff options
Diffstat (limited to 'Linux-PAM/modules/pam_namespace/pam_namespace.c')
| -rw-r--r-- | Linux-PAM/modules/pam_namespace/pam_namespace.c | 1907 |
1 files changed, 0 insertions, 1907 deletions
diff --git a/Linux-PAM/modules/pam_namespace/pam_namespace.c b/Linux-PAM/modules/pam_namespace/pam_namespace.c deleted file mode 100644 index d0741fd2..00000000 --- a/Linux-PAM/modules/pam_namespace/pam_namespace.c +++ /dev/null @@ -1,1907 +0,0 @@ -/****************************************************************************** - * 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, Inc. 2006, 2008 - * All Rights Reserved. - * - * Written by: Janak Desai <janak@us.ibm.com> - * With Revisions by: Steve Grubb <sgrubb@redhat.com> - * Contributions by: Xavier Toth <txtoth@gmail.com>, - * Tomas Mraz <tmraz@redhat.com> - * Derived from a namespace setup patch by Chad Sellers <cdselle@tycho.nsa.gov> - * - * 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. - */ - -#include "pam_namespace.h" -#include "argv_parse.h" - -/* - * Adds an entry for a polyinstantiated directory to the linked list of - * polyinstantiated directories. It is called from process_line() while - * parsing the namespace configuration file. - */ -static void add_polydir_entry(struct instance_data *idata, - struct polydir_s *ent) -{ - /* Now attach to linked list */ - ent->next = NULL; - if (idata->polydirs_ptr == NULL) - idata->polydirs_ptr = ent; - else { - struct polydir_s *tail; - - tail = idata->polydirs_ptr; - while (tail->next) - tail = tail->next; - tail->next = ent; - } -} - -static void del_polydir(struct polydir_s *poly) -{ - free(poly->uid); - free(poly->init_script); - free(poly); -} - -/* - * Deletes all the entries in the linked list. - */ -static void del_polydir_list(struct polydir_s *polydirs_ptr) -{ - struct polydir_s *dptr = polydirs_ptr; - - while (dptr) { - struct polydir_s *tptr = dptr; - dptr = dptr->next; - del_polydir(tptr); - } -} - -static void cleanup_data(pam_handle_t *pamh UNUSED , void *data, int err UNUSED) -{ - del_polydir_list(data); -} - -static char *expand_variables(const char *orig, const char *var_names[], const char *var_values[]) -{ - const char *src = orig; - char *dst; - char *expanded; - char c; - size_t dstlen = 0; - while (*src) { - if (*src == '$') { - int i; - for (i = 0; var_names[i]; i++) { - int namelen = strlen(var_names[i]); - if (strncmp(var_names[i], src+1, namelen) == 0) { - dstlen += strlen(var_values[i]) - 1; /* $ */ - src += namelen; - break; - } - } - } - ++dstlen; - ++src; - } - if ((dst=expanded=malloc(dstlen + 1)) == NULL) - return NULL; - src = orig; - while ((c=*src) != '\0') { - if (c == '$') { - int i; - for (i = 0; var_names[i]; i++) { - int namelen = strlen(var_names[i]); - if (strncmp(var_names[i], src+1, namelen) == 0) { - dst = stpcpy(dst, var_values[i]); - --dst; - c = *dst; /* replace $ */ - src += namelen; - break; - } - } - } - *dst = c; - ++dst; - ++src; - } - *dst = '\0'; - return expanded; -} - -static int parse_create_params(char *params, struct polydir_s *poly) -{ - char *sptr; - struct passwd *pwd; - struct group *grp; - - poly->mode = (mode_t)ULONG_MAX; - poly->owner = (uid_t)ULONG_MAX; - poly->group = (gid_t)ULONG_MAX; - - if (*params != '=') - return 0; - params++; - - params = strtok_r(params, ",", &sptr); - if (params == NULL) - return 0; - - errno = 0; - poly->mode = (mode_t)strtoul(params, NULL, 0); - if (errno != 0) { - poly->mode = (mode_t)ULONG_MAX; - } - - params = strtok_r(NULL, ",", &sptr); - if (params == NULL) - return 0; - - pwd = getpwnam(params); /* session modules are not reentrant */ - if (pwd == NULL) - return -1; - poly->owner = pwd->pw_uid; - - params = strtok_r(NULL, ",", &sptr); - if (params == NULL) { - poly->group = pwd->pw_gid; - return 0; - } - grp = getgrnam(params); - if (grp == NULL) - return -1; - poly->group = grp->gr_gid; - - return 0; -} - -static int parse_iscript_params(char *params, struct polydir_s *poly) -{ - if (*params != '=') - return 0; - params++; - - if (*params != '\0') { - if (*params != '/') { /* path is relative to NAMESPACE_D_DIR */ - if (asprintf(&poly->init_script, "%s%s", NAMESPACE_D_DIR, params) == -1) - return -1; - } else { - poly->init_script = strdup(params); - } - if (poly->init_script == NULL) - return -1; - } - return 0; -} - -static int parse_method(char *method, struct polydir_s *poly, - struct instance_data *idata) -{ - enum polymethod pm; - char *sptr; - static const char *method_names[] = { "user", "context", "level", "tmpdir", - "tmpfs", NULL }; - static const char *flag_names[] = { "create", "noinit", "iscript", - "shared", NULL }; - static const unsigned int flag_values[] = { POLYDIR_CREATE, POLYDIR_NOINIT, - POLYDIR_ISCRIPT, POLYDIR_SHARED }; - int i; - char *flag; - - method = strtok_r(method, ":", &sptr); - pm = NONE; - - for (i = 0; method_names[i]; i++) { - if (strcmp(method, method_names[i]) == 0) { - pm = i + 1; /* 0 = NONE */ - } - } - - if (pm == NONE) { - pam_syslog(idata->pamh, LOG_NOTICE, "Unknown method"); - return -1; - } - - poly->method = pm; - - while ((flag=strtok_r(NULL, ":", &sptr)) != NULL) { - for (i = 0; flag_names[i]; i++) { - int namelen = strlen(flag_names[i]); - - if (strncmp(flag, flag_names[i], namelen) == 0) { - poly->flags |= flag_values[i]; - switch (flag_values[i]) { - case POLYDIR_CREATE: - if (parse_create_params(flag+namelen, poly) != 0) { - pam_syslog(idata->pamh, LOG_CRIT, "Invalid create parameters"); - return -1; - } - break; - - case POLYDIR_ISCRIPT: - if (parse_iscript_params(flag+namelen, poly) != 0) { - pam_syslog(idata->pamh, LOG_CRIT, "Memory allocation error"); - return -1; - }; - break; - } - } - } - } - - return 0; -} - -/* - * Called from parse_config_file, this function processes a single line - * of the namespace configuration file. It skips over comments and incomplete - * or malformed lines. It processes a valid line with information on - * polyinstantiating a directory by populating appropriate fields of a - * polyinstatiated directory structure and then calling add_polydir_entry to - * add that entry to the linked list of polyinstantiated directories. - */ -static int process_line(char *line, const char *home, const char *rhome, - struct instance_data *idata) -{ - char *dir = NULL, *instance_prefix = NULL, *rdir = NULL; - char *method, *uids; - char *tptr; - struct polydir_s *poly; - int retval = 0; - char **config_options = NULL; - static const char *var_names[] = {"HOME", "USER", NULL}; - const char *var_values[] = {home, idata->user}; - const char *rvar_values[] = {rhome, idata->ruser}; - int len; - - poly = calloc(1, sizeof(*poly)); - if (poly == NULL) - goto erralloc; - - /* - * skip the leading white space - */ - while (*line && isspace(*line)) - line++; - - /* - * Rip off the comments - */ - tptr = strchr(line,'#'); - if (tptr) - *tptr = '\0'; - - /* - * Rip off the newline char - */ - tptr = strchr(line,'\n'); - if (tptr) - *tptr = '\0'; - - /* - * Anything left ? - */ - if (line[0] == 0) - return 0; - - /* - * Initialize and scan the five strings from the line from the - * namespace configuration file. - */ - retval = argv_parse(line, NULL, &config_options); - if (retval != 0) { - goto erralloc; - } - - dir = config_options[0]; - if (dir == NULL) { - pam_syslog(idata->pamh, LOG_NOTICE, "Invalid line missing polydir"); - goto skipping; - } - instance_prefix = config_options[1]; - if (instance_prefix == NULL) { - pam_syslog(idata->pamh, LOG_NOTICE, "Invalid line missing instance_prefix"); - instance_prefix = NULL; - goto skipping; - } - method = config_options[2]; - if (method == NULL) { - pam_syslog(idata->pamh, LOG_NOTICE, "Invalid line missing method"); - instance_prefix = NULL; - dir = NULL; - goto skipping; - } - - /* - * Only the uids field is allowed to be blank, to indicate no - * override users for polyinstantiation of that directory. If - * any of the other fields are blank, the line is incomplete so - * skip it. - */ - uids = config_options[3]; - - /* - * Expand $HOME and $USER in poly dir and instance dir prefix - */ - if ((rdir=expand_variables(dir, var_names, rvar_values)) == NULL) { - instance_prefix = NULL; - dir = NULL; - goto erralloc; - } - - if ((dir=expand_variables(dir, var_names, var_values)) == NULL) { - instance_prefix = NULL; - goto erralloc; - } - - if ((instance_prefix=expand_variables(instance_prefix, var_names, var_values)) - == NULL) { - goto erralloc; - } - - if (idata->flags & PAMNS_DEBUG) { - pam_syslog(idata->pamh, LOG_DEBUG, "Expanded polydir: '%s'", dir); - pam_syslog(idata->pamh, LOG_DEBUG, "Expanded ruser polydir: '%s'", rdir); - pam_syslog(idata->pamh, LOG_DEBUG, "Expanded instance prefix: '%s'", instance_prefix); - } - - len = strlen(dir); - if (len > 0 && dir[len-1] == '/') { - dir[len-1] = '\0'; - } - - len = strlen(rdir); - if (len > 0 && rdir[len-1] == '/') { - rdir[len-1] = '\0'; - } - - if (dir[0] == '\0' || rdir[0] == '\0') { - pam_syslog(idata->pamh, LOG_NOTICE, "Invalid polydir"); - goto skipping; - } - - /* - * Populate polyinstantiated directory structure with appropriate - * pathnames and the method with which to polyinstantiate. - */ - if (strlen(dir) >= sizeof(poly->dir) - || strlen(rdir) >= sizeof(poly->rdir) - || strlen(instance_prefix) >= sizeof(poly->instance_prefix)) { - pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames too long"); - goto skipping; - } - strcpy(poly->dir, dir); - strcpy(poly->rdir, rdir); - strcpy(poly->instance_prefix, instance_prefix); - - if (parse_method(method, poly, idata) != 0) { - goto skipping; - } - - if (poly->method == TMPDIR) { - if (sizeof(poly->instance_prefix) - strlen(poly->instance_prefix) < 7) { - pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames too long"); - goto skipping; - } - strcat(poly->instance_prefix, "XXXXXX"); - } - - /* - * Ensure that all pathnames are absolute path names. - */ - if ((poly->dir[0] != '/') || (poly->method != TMPFS && poly->instance_prefix[0] != '/')) { - pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames must start with '/'"); - goto skipping; - } - if (strstr(dir, "..") || strstr(poly->instance_prefix, "..")) { - pam_syslog(idata->pamh, LOG_NOTICE, "Pathnames must not contain '..'"); - goto skipping; - } - - /* - * If the line in namespace.conf for a directory to polyinstantiate - * contains a list of override users (users for whom polyinstantiation - * is not performed), read the user ids, convert names into uids, and - * add to polyinstantiated directory structure. - */ - if (uids) { - uid_t *uidptr; - const char *ustr, *sstr; - int count, i; - - if (*uids == '~') { - poly->flags |= POLYDIR_EXCLUSIVE; - uids++; - } - for (count = 0, ustr = sstr = uids; sstr; ustr = sstr + 1, count++) - sstr = strchr(ustr, ','); - - poly->num_uids = count; - poly->uid = (uid_t *) malloc(count * sizeof (uid_t)); - uidptr = poly->uid; - if (uidptr == NULL) { - goto erralloc; - } - - ustr = uids; - for (i = 0; i < count; i++) { - struct passwd *pwd; - - tptr = strchr(ustr, ','); - if (tptr) - *tptr = '\0'; - - pwd = pam_modutil_getpwnam(idata->pamh, ustr); - if (pwd == NULL) { - pam_syslog(idata->pamh, LOG_ERR, "Unknown user %s in configuration", ustr); - poly->num_uids--; - } else { - *uidptr = pwd->pw_uid; - uidptr++; - } - ustr = tptr + 1; - } - } - - /* - * Add polyinstantiated directory structure to the linked list - * of all polyinstantiated directory structures. - */ - add_polydir_entry(idata, poly); - - goto out; - -erralloc: - pam_syslog(idata->pamh, LOG_CRIT, "Memory allocation error"); - -skipping: - if (idata->flags & PAMNS_IGN_CONFIG_ERR) - retval = 0; - else - retval = PAM_SERVICE_ERR; - del_polydir(poly); -out: - free(rdir); - free(dir); - free(instance_prefix); - argv_free(config_options); - return retval; -} - - -/* - * Parses /etc/security/namespace.conf file to build a linked list of - * polyinstantiated directory structures of type polydir_s. Each entry - * in the linked list contains information needed to polyinstantiate - * one directory. - */ -static int parse_config_file(struct instance_data *idata) -{ - FILE *fil; - char *home, *rhome; - const char *confname; - struct passwd *cpwd; - char *line; - int retval; - size_t len = 0; - glob_t globbuf; - const char *oldlocale; - size_t n; - - /* - * Extract the user's home directory to resolve $HOME entries - * in the namespace configuration file. - */ - cpwd = pam_modutil_getpwnam(idata->pamh, idata->user); - if (!cpwd) { - pam_syslog(idata->pamh, LOG_ERR, - "Error getting home dir for '%s'", idata->user); - return PAM_SESSION_ERR; - } - if ((home=strdup(cpwd->pw_dir)) == NULL) { - pam_syslog(idata->pamh, LOG_CRIT, - "Memory allocation error"); - return PAM_SESSION_ERR; - } - - cpwd = pam_modutil_getpwnam(idata->pamh, idata->ruser); - if (!cpwd) { - pam_syslog(idata->pamh, LOG_ERR, - "Error getting home dir for '%s'", idata->ruser); - free(home); - return PAM_SESSION_ERR; - } - - if ((rhome=strdup(cpwd->pw_dir)) == NULL) { - pam_syslog(idata->pamh, LOG_CRIT, - "Memory allocation error"); - free(home); - return PAM_SESSION_ERR; - } - - /* - * Open configuration file, read one line at a time and call - * process_line to process each line. - */ - - memset(&globbuf, '\0', sizeof(globbuf)); - oldlocale = setlocale(LC_COLLATE, "C"); - glob(NAMESPACE_D_GLOB, 0, NULL, &globbuf); - if (oldlocale != NULL) - setlocale(LC_COLLATE, oldlocale); - - confname = PAM_NAMESPACE_CONFIG; - n = 0; - for (;;) { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "Parsing config file %s", - confname); - fil = fopen(confname, "r"); - if (fil == NULL) { - pam_syslog(idata->pamh, LOG_ERR, "Error opening config file %s", - confname); - globfree(&globbuf); - free(rhome); - free(home); - return PAM_SERVICE_ERR; - } - - /* Use unlocked IO */ - __fsetlocking(fil, FSETLOCKING_BYCALLER); - - line = NULL; - /* loop reading the file */ - while (getline(&line, &len, fil) > 0) { - retval = process_line(line, home, rhome, idata); - if (retval) { - pam_syslog(idata->pamh, LOG_ERR, - "Error processing conf file %s line %s", confname, line); - fclose(fil); - free(line); - globfree(&globbuf); - free(rhome); - free(home); - return PAM_SERVICE_ERR; - } - } - fclose(fil); - free(line); - - if (n >= globbuf.gl_pathc) - break; - - confname = globbuf.gl_pathv[n]; - n++; - } - - globfree(&globbuf); - free(rhome); - free(home); - - /* All done...just some debug stuff */ - if (idata->flags & PAMNS_DEBUG) { - struct polydir_s *dptr = idata->polydirs_ptr; - uid_t *iptr; - uid_t i; - - pam_syslog(idata->pamh, LOG_DEBUG, - dptr?"Configured poly dirs:":"No configured poly dirs"); - while (dptr) { - pam_syslog(idata->pamh, LOG_DEBUG, "dir='%s' iprefix='%s' meth=%d", - dptr->dir, dptr->instance_prefix, dptr->method); - for (i = 0, iptr = dptr->uid; i < dptr->num_uids; i++, iptr++) - pam_syslog(idata->pamh, LOG_DEBUG, "override user %d ", *iptr); - dptr = dptr->next; - } - } - - return PAM_SUCCESS; -} - - -/* - * This funtion returns true if a given uid is present in the polyinstantiated - * directory's list of override uids. If the uid is one of the override - * uids for the polyinstantiated directory, polyinstantiation is not - * performed for that user for that directory. - * If exclusive is set the returned values are opposite. - */ -static int ns_override(struct polydir_s *polyptr, struct instance_data *idata, - uid_t uid) -{ - unsigned int i; - - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Checking for ns override in dir %s for uid %d", - polyptr->dir, uid); - - for (i = 0; i < polyptr->num_uids; i++) { - if (uid == polyptr->uid[i]) { - return !(polyptr->flags & POLYDIR_EXCLUSIVE); - } - } - - return !!(polyptr->flags & POLYDIR_EXCLUSIVE); -} - -/* - * md5hash generates a hash of the passed in instance directory name. - */ -static char *md5hash(const char *instname, struct instance_data *idata) -{ - int i; - char *md5inst = NULL; - char *to; - unsigned char inst_digest[MD5_DIGEST_LENGTH]; - - /* - * Create MD5 hashes for instance pathname. - */ - - MD5((const unsigned char *)instname, strlen(instname), inst_digest); - - if ((md5inst = malloc(MD5_DIGEST_LENGTH * 2 + 1)) == NULL) { - pam_syslog(idata->pamh, LOG_ERR, "Unable to allocate buffer"); - return NULL; - } - - to = md5inst; - for (i = 0; i < MD5_DIGEST_LENGTH; i++) { - snprintf(to, 3, "%02x", (unsigned int)inst_digest[i]); - to += 2; - } - - return md5inst; -} - -#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 (polyptr->method == USER) return PAM_SUCCESS; - - if (idata->flags & PAMNS_USE_CURRENT_CONTEXT) { - rc = getcon(&scon); - } else if (idata->flags & PAMNS_USE_DEFAULT_CONTEXT) { - char *seuser = NULL, *level = NULL; - - if ((rc=getseuserbyname(idata->user, &seuser, &level)) == 0) { - rc = get_default_context_with_level(seuser, level, NULL, &scon); - free(seuser); - free(level); - } - } else { - rc = getexeccon(&scon); - } - if (rc < 0 || scon == NULL) { - pam_syslog(idata->pamh, LOG_ERR, - "Error getting exec 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) { - 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; - } - - /* - * If polyinstantiating based on security level, get current - * process security context, get security class for directories, - * and change the directories MLS Level to match process. - */ - - if (polyptr->method == LEVEL) { - context_t scontext = NULL; - context_t fcontext = NULL; - rc = PAM_SESSION_ERR; - - scontext = context_new(scon); - if (! scontext) { - pam_syslog(idata->pamh, LOG_ERR, "out of memory"); - goto fail; - } - fcontext = context_new(*origcon); - if (! fcontext) { - pam_syslog(idata->pamh, LOG_ERR, "out of memory"); - goto fail; - } - if (context_range_set(fcontext, context_range_get(scontext)) != 0) { - pam_syslog(idata->pamh, LOG_ERR, "Unable to set MLS Componant of context"); - goto fail; - } - *i_context=strdup(context_str(fcontext)); - if (! *i_context) { - pam_syslog(idata->pamh, LOG_ERR, "out of memory"); - goto fail; - } - - rc = PAM_SUCCESS; - fail: - context_free(scontext); - context_free(fcontext); - freecon(scon); - return rc; - } - /* Should never get here */ - return PAM_SUCCESS; -} -#endif - -/* - * poly_name returns the name of the polyinstantiated instance directory - * based on the method used for polyinstantiation (user, context or level) - * In addition, the function also returns the security contexts of the - * original directory to polyinstantiate and the polyinstantiated instance - * directory. - */ -#ifdef WITH_SELINUX -static int poly_name(const struct polydir_s *polyptr, char **i_name, - security_context_t *i_context, security_context_t *origcon, - struct instance_data *idata) -#else -static int poly_name(const struct polydir_s *polyptr, char **i_name, - struct instance_data *idata) -#endif -{ - int rc; - char *hash = NULL; - enum polymethod pm; -#ifdef WITH_SELINUX - security_context_t rawcon = NULL; -#endif - - *i_name = NULL; -#ifdef WITH_SELINUX - *i_context = NULL; - *origcon = NULL; - if ((idata->flags & PAMNS_SELINUX_ENABLED) && - (rc=form_context(polyptr, i_context, origcon, idata)) != PAM_SUCCESS) { - return rc; - } -#endif - - rc = PAM_SESSION_ERR; - /* - * Set the name of the polyinstantiated instance dir based on the - * polyinstantiation method. - */ - - pm = polyptr->method; - if (pm == LEVEL || pm == USER) { -#ifdef WITH_SELINUX - if (!(idata->flags & PAMNS_CTXT_BASED_INST)) -#else - pam_syslog(idata->pamh, LOG_NOTICE, - "Context and level methods not available, using user method"); -#endif - if (polyptr->flags & POLYDIR_SHARED) { - rc = PAM_IGNORE; - goto fail; - } - pm = USER; - } - - switch (pm) { - case USER: - if (asprintf(i_name, "%s", idata->user) < 0) { - *i_name = NULL; - goto fail; - } - break; - -#ifdef WITH_SELINUX - case LEVEL: - case CONTEXT: - if (selinux_trans_to_raw_context(*i_context, &rawcon) < 0) { - pam_syslog(idata->pamh, LOG_ERR, "Error translating directory context"); - goto fail; - } - if (polyptr->flags & POLYDIR_SHARED) { - if (asprintf(i_name, "%s", rawcon) < 0) { - *i_name = NULL; - goto fail; - } - } else { - if (asprintf(i_name, "%s_%s", rawcon, idata->user) < 0) { - *i_name = NULL; - goto fail; - } - } - break; - -#endif /* WITH_SELINUX */ - - case TMPDIR: - case TMPFS: - if ((*i_name=strdup("")) == NULL) - goto fail; - return PAM_SUCCESS; - - default: - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_ERR, "Unknown method"); - goto fail; - } - - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "poly_name %s", *i_name); - - if ((idata->flags & PAMNS_GEN_HASH) || strlen(*i_name) > NAMESPACE_MAX_DIR_LEN) { - hash = md5hash(*i_name, idata); - if (hash == NULL) { - goto fail; - } - if (idata->flags & PAMNS_GEN_HASH) { - free(*i_name); - *i_name = hash; - hash = NULL; - } else { - char *newname; - if (asprintf(&newname, "%.*s_%s", NAMESPACE_MAX_DIR_LEN-1-(int)strlen(hash), - *i_name, hash) < 0) { - goto fail; - } - free(*i_name); - *i_name = newname; - } - } - rc = PAM_SUCCESS; - -fail: - free(hash); -#ifdef WITH_SELINUX - freecon(rawcon); -#endif - if (rc != PAM_SUCCESS) { -#ifdef WITH_SELINUX - freecon(*i_context); - *i_context = NULL; - freecon(*origcon); - *origcon = NULL; -#endif - free(*i_name); - *i_name = NULL; - } - 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, const char *ipath, - struct instance_data *idata, int newdir) -{ - pid_t rc, pid; - sighandler_t osighand = NULL; - int status; - const char *init_script = NAMESPACE_INIT_SCRIPT; - - 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 ((polyptr->flags & POLYDIR_ISCRIPT) && polyptr->init_script) - init_script = polyptr->init_script; - - if (access(init_script, F_OK) == 0) { - if (access(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(init_script, init_script, - polyptr->dir, ipath, newdir?"1":"0", idata->user, (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; -} - -static int create_polydir(struct polydir_s *polyptr, - struct instance_data *idata) -{ - mode_t mode; - int rc; -#ifdef WITH_SELINUX - security_context_t dircon, oldcon = NULL; -#endif - const char *dir = polyptr->dir; - - if (polyptr->mode != (mode_t)ULONG_MAX) - mode = polyptr->mode; - else - mode = 0777; - -#ifdef WITH_SELINUX - if (idata->flags & PAMNS_SELINUX_ENABLED) { - getfscreatecon(&oldcon); - rc = matchpathcon(dir, S_IFDIR, &dircon); - if (rc) { - pam_syslog(idata->pamh, LOG_NOTICE, - "Unable to get default context for directory %s, check your policy: %m", dir); - } else { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Polydir %s context: %s", dir, (char *)dircon); - if (setfscreatecon(dircon) != 0) - pam_syslog(idata->pamh, LOG_NOTICE, - "Error setting context for directory %s: %m", dir); - freecon(dircon); - } - matchpathcon_fini(); - } -#endif - - rc = mkdir(dir, mode); - if (rc != 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Error creating directory %s: %m", dir); - return PAM_SESSION_ERR; - } - -#ifdef WITH_SELINUX - if (idata->flags & PAMNS_SELINUX_ENABLED) { - if (setfscreatecon(oldcon) != 0) - pam_syslog(idata->pamh, LOG_NOTICE, - "Error resetting fs create context: %m"); - freecon(oldcon); - } -#endif - - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "Created polydir %s", dir); - - if (polyptr->mode != (mode_t)ULONG_MAX) { - /* explicit mode requested */ - if (chmod(dir, mode) != 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Error changing mode of directory %s: %m", dir); - rmdir(dir); - return PAM_SESSION_ERR; - } - } - - if (polyptr->owner != (uid_t)ULONG_MAX) { - if (chown(dir, polyptr->owner, polyptr->group) != 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Unable to change owner on directory %s: %m", dir); - rmdir(dir); - return PAM_SESSION_ERR; - } - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Polydir owner %u group %u from configuration", polyptr->owner, polyptr->group); - } else { - if (chown(dir, idata->uid, idata->gid) != 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Unable to change owner on directory %s: %m", dir); - rmdir(dir); - return PAM_SESSION_ERR; - } - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Polydir owner %u group %u", idata->uid, idata->gid); - } - - return PAM_SUCCESS; -} - -/* - * Create polyinstantiated instance directory (ipath). - */ -#ifdef WITH_SELINUX -static int create_dirs(struct polydir_s *polyptr, char *ipath, struct stat *statbuf, - security_context_t icontext, security_context_t ocontext, - struct instance_data *idata) -#else -static int create_dirs(struct polydir_s *polyptr, char *ipath, struct stat *statbuf, - struct instance_data *idata) -#endif -{ - struct stat newstatbuf; - int fd; - int newdir = 0; - - /* - * 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 - * returned by the security policy. Set its mode and ownership - * attributes to match that of the original directory that is being - * polyinstantiated. - */ - - if (polyptr->method == TMPDIR) { - if (mkdtemp(polyptr->instance_prefix) == NULL) { - pam_syslog(idata->pamh, LOG_ERR, "Error creating temporary instance %s, %m", - polyptr->instance_prefix); - polyptr->method = NONE; /* do not clean up! */ - return PAM_SESSION_ERR; - } - /* copy the actual directory name to ipath */ - strcpy(ipath, polyptr->instance_prefix); - } else if (mkdir(ipath, S_IRUSR) < 0) { - if (errno == EEXIST) - goto inst_init; - else { - pam_syslog(idata->pamh, LOG_ERR, "Error creating %s, %m", - ipath); - return PAM_SESSION_ERR; - } - } - - newdir = 1; - /* Open a descriptor to it to prevent races */ - fd = open(ipath, O_DIRECTORY | O_RDONLY); - if (fd < 0) { - pam_syslog(idata->pamh, LOG_ERR, "Error opening %s, %m", ipath); - rmdir(ipath); - return PAM_SESSION_ERR; - } -#ifdef WITH_SELINUX - /* If SE Linux is disabled, no need to label it */ - if (idata->flags & PAMNS_SELINUX_ENABLED) { - /* If method is USER, icontext is NULL */ - if (icontext) { - if (fsetfilecon(fd, icontext) < 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Error setting context of %s to %s", ipath, icontext); - close(fd); - rmdir(ipath); - return PAM_SESSION_ERR; - } - } else { - if (fsetfilecon(fd, ocontext) < 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Error setting context of %s to %s", ipath, ocontext); - close(fd); - rmdir(ipath); - return PAM_SESSION_ERR; - } - } - } -#endif - if (fstat(fd, &newstatbuf) < 0) { - pam_syslog(idata->pamh, LOG_ERR, "Error stating %s, %m", - ipath); - rmdir(ipath); - return PAM_SESSION_ERR; - } - if (newstatbuf.st_uid != statbuf->st_uid || - newstatbuf.st_gid != statbuf->st_gid) { - if (fchown(fd, statbuf->st_uid, statbuf->st_gid) < 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Error changing owner for %s, %m", - ipath); - close(fd); - rmdir(ipath); - return PAM_SESSION_ERR; - } - } - if (fchmod(fd, statbuf->st_mode & 07777) < 0) { - pam_syslog(idata->pamh, LOG_ERR, "Error changing mode for %s, %m", - ipath); - close(fd); - rmdir(ipath); - return PAM_SESSION_ERR; - } - close(fd); - - /* - * 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. - */ - -inst_init: - if (polyptr->flags & POLYDIR_NOINIT) - return PAM_SUCCESS; - - return inst_init(polyptr, ipath, idata, newdir); -} - - -/* - * This function performs the namespace setup for a particular directory - * that is being polyinstantiated. It creates an MD5 hash of instance - * directory, calls create_dirs to create it with appropriate - * security attributes, and performs bind mount to setup the process - * namespace. - */ -static int ns_setup(struct polydir_s *polyptr, - struct instance_data *idata) -{ - int retval = 0; - char *inst_dir = NULL; - char *instname = NULL; - struct stat statbuf; -#ifdef WITH_SELINUX - security_context_t instcontext = NULL, origcontext = NULL; -#endif - - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Set namespace for directory %s", polyptr->dir); - - while (stat(polyptr->dir, &statbuf) < 0) { - if (retval || !(polyptr->flags & POLYDIR_CREATE)) { - pam_syslog(idata->pamh, LOG_ERR, "Error stating %s, %m", - polyptr->dir); - return PAM_SESSION_ERR; - } else { - if (create_polydir(polyptr, idata) != PAM_SUCCESS) - return PAM_SESSION_ERR; - retval = PAM_SESSION_ERR; /* bail out on next failed stat */ - } - } - - /* - * Make sure we are dealing with a directory - */ - if (!S_ISDIR(statbuf.st_mode)) { - pam_syslog(idata->pamh, LOG_ERR, "Polydir %s is not a dir", - polyptr->dir); - return PAM_SESSION_ERR; - } - - if (polyptr->method == TMPFS) { - if (mount("tmpfs", polyptr->dir, "tmpfs", 0, NULL) < 0) { - pam_syslog(idata->pamh, LOG_ERR, "Error mounting tmpfs on %s, %m", - polyptr->dir); - return PAM_SESSION_ERR; - } - /* we must call inst_init after the mount in this case */ - return inst_init(polyptr, "tmpfs", idata, 1); - } - - /* - * Obtain the name of instance pathname based on the - * polyinstantiation method and instance context returned by - * security policy. - */ -#ifdef WITH_SELINUX - retval = poly_name(polyptr, &instname, &instcontext, - &origcontext, idata); -#else - retval = poly_name(polyptr, &instname, idata); -#endif - - if (retval != PAM_SUCCESS) { - if (retval != PAM_IGNORE) - pam_syslog(idata->pamh, LOG_ERR, "Error getting instance name"); - goto cleanup; - } else { -#ifdef WITH_SELINUX - if ((idata->flags & PAMNS_DEBUG) && - (idata->flags & PAMNS_SELINUX_ENABLED)) - pam_syslog(idata->pamh, LOG_DEBUG, "Inst ctxt %s Orig ctxt %s", - instcontext, origcontext); -#endif - } - - if (asprintf(&inst_dir, "%s%s", polyptr->instance_prefix, instname) < 0) - goto error_out; - - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "instance_dir %s", - inst_dir); - - /* - * Create instance directory with appropriate security - * contexts, owner, group and mode bits. - */ -#ifdef WITH_SELINUX - retval = create_dirs(polyptr, inst_dir, &statbuf, instcontext, - origcontext, idata); -#else - retval = create_dirs(polyptr, inst_dir, &statbuf, idata); -#endif - - if (retval < 0) { - pam_syslog(idata->pamh, LOG_ERR, "Error creating instance dir"); - goto error_out; - } - - /* - * Bind mount instance directory on top of the polyinstantiated - * directory to provide an instance of polyinstantiated directory - * based on polyinstantiated method. - */ - if (mount(inst_dir, polyptr->dir, NULL, MS_BIND, NULL) < 0) { - pam_syslog(idata->pamh, LOG_ERR, "Error mounting %s on %s, %m", - inst_dir, polyptr->dir); - goto error_out; - } - - goto cleanup; - - /* - * various error exit points. Free allocated memory and set return - * value to indicate a pam session error. - */ -error_out: - retval = PAM_SESSION_ERR; - -cleanup: - free(inst_dir); - free(instname); -#ifdef WITH_SELINUX - freecon(instcontext); - freecon(origcontext); -#endif - return retval; -} - - -/* - * This function checks to see if the current working directory is - * inside the directory passed in as the first argument. - */ -static int cwd_in(char *dir, struct instance_data *idata) -{ - int retval = 0; - char cwd[PATH_MAX]; - - if (getcwd(cwd, PATH_MAX) == NULL) { - pam_syslog(idata->pamh, LOG_ERR, "Can't get current dir, %m"); - return -1; - } - - if (strncmp(cwd, dir, strlen(dir)) == 0) { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "cwd is inside %s", dir); - retval = 1; - } else { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "cwd is outside %s", dir); - } - - return retval; -} - -static int cleanup_tmpdirs(struct instance_data *idata) -{ - struct polydir_s *pptr; - 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; - } - - for (pptr = idata->polydirs_ptr; pptr; pptr = pptr->next) { - if (pptr->method == TMPDIR && access(pptr->instance_prefix, F_OK) == 0) { - pid = fork(); - if (pid == 0) { -#ifdef WITH_SELINUX - if (idata->flags & PAMNS_SELINUX_ENABLED) { - if (setexeccon(NULL) < 0) - exit(1); - } -#endif - if (execl("/bin/rm", "/bin/rm", "-rf", pptr->instance_prefix, (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 removing %s", pptr->instance_prefix); - } - } 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: - signal(SIGCHLD, osighand); - return rc; -} - -/* - * This function checks to see if polyinstantiation is needed for any - * of the directories listed in the configuration file. If needed, - * cycles through all polyinstantiated directory entries and calls - * ns_setup to setup polyinstantiation for each one of them. - */ -static int setup_namespace(struct instance_data *idata, enum unmnt_op unmnt) -{ - int retval = 0, need_poly = 0, changing_dir = 0; - char *cptr, *fptr, poly_parent[PATH_MAX]; - struct polydir_s *pptr; - - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "Set up namespace for pid %d", - getpid()); - - /* - * Cycle through all polyinstantiated directory entries to see if - * polyinstantiation is needed at all. - */ - for (pptr = idata->polydirs_ptr; pptr; pptr = pptr->next) { - if (ns_override(pptr, idata, idata->uid)) { - if (unmnt == NO_UNMNT || ns_override(pptr, idata, idata->ruid)) { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Overriding poly for user %d for dir %s", - idata->uid, pptr->dir); - } else { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Need unmount ns for user %d for dir %s", - idata->ruid, pptr->dir); - need_poly = 1; - break; - } - continue; - } else { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Need poly ns for user %d for dir %s", - idata->uid, pptr->dir); - need_poly = 1; - break; - } - } - - /* - * If polyinstantiation is needed, call the unshare system call to - * disassociate from the parent namespace. - */ - if (need_poly) { - if (unshare(CLONE_NEWNS) < 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Unable to unshare from parent namespace, %m"); - return PAM_SESSION_ERR; - } - } else { - del_polydir_list(idata->polydirs_ptr); - return PAM_SUCCESS; - } - - /* - * Again cycle through all polyinstantiated directories, this time, - * call ns_setup to setup polyinstantiation for a particular entry. - */ - for (pptr = idata->polydirs_ptr; pptr; pptr = pptr->next) { - enum unmnt_op dir_unmnt = unmnt; - if (ns_override(pptr, idata, idata->uid)) { - if (unmnt == NO_UNMNT || ns_override(pptr, idata, idata->ruid)) { - continue; - } else { - dir_unmnt = UNMNT_ONLY; - } - } - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Setting poly ns for user %d for dir %s", - idata->uid, pptr->dir); - - if ((dir_unmnt == UNMNT_REMNT) || (dir_unmnt == UNMNT_ONLY)) { - /* - * Check to see if process current directory is in the - * bind mounted instance_parent directory that we are trying to - * umount - */ - if ((changing_dir = cwd_in(pptr->rdir, idata)) < 0) { - retval = PAM_SESSION_ERR; - goto out; - } else if (changing_dir) { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "changing cwd"); - - /* - * Change current working directory to the parent of - * the mount point, that is parent of the orig - * directory where original contents of the polydir - * are available from - */ - strcpy(poly_parent, pptr->rdir); - fptr = strchr(poly_parent, '/'); - cptr = strrchr(poly_parent, '/'); - if (fptr && cptr && (fptr == cptr)) - strcpy(poly_parent, "/"); - else if (cptr) - *cptr = '\0'; - if (chdir(poly_parent) < 0) { - pam_syslog(idata->pamh, LOG_ERR, - "Can't chdir to %s, %m", poly_parent); - } - } - - if (umount(pptr->rdir) < 0) { - int saved_errno = errno; - pam_syslog(idata->pamh, LOG_ERR, "Unmount of %s failed, %m", - pptr->rdir); - if (saved_errno != EINVAL) { - retval = PAM_SESSION_ERR; - goto out; - } - } else if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "Umount succeeded %s", - pptr->rdir); - } - - if (dir_unmnt != UNMNT_ONLY) { - retval = ns_setup(pptr, idata); - if (retval == PAM_IGNORE) - retval = PAM_SUCCESS; - if (retval != PAM_SUCCESS) - break; - } - } -out: - if (retval != PAM_SUCCESS) - cleanup_tmpdirs(idata); - else if (pam_set_data(idata->pamh, NAMESPACE_POLYDIR_DATA, idata->polydirs_ptr, - cleanup_data) != PAM_SUCCESS) { - pam_syslog(idata->pamh, LOG_ERR, "Unable to set namespace data"); - cleanup_tmpdirs(idata); - return PAM_SYSTEM_ERR; - } - return retval; -} - - -/* - * Orig namespace. This function is called from when closing a pam - * session. If authorized, it unmounts instance directory. - */ -static int orig_namespace(struct instance_data *idata) -{ - struct polydir_s *pptr; - - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "orig namespace for pid %d", - getpid()); - - /* - * Cycle through all polyinstantiated directories from the namespace - * configuration file to see if polyinstantiation was performed for - * this user for each of the entry. If it was, try and unmount - * appropriate polyinstantiated instance directories. - */ - for (pptr = idata->polydirs_ptr; pptr; pptr = pptr->next) { - if (ns_override(pptr, idata, idata->uid)) - continue; - else { - if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, - "Unmounting instance dir for user %d & dir %s", - idata->uid, pptr->dir); - - if (umount(pptr->dir) < 0) { - pam_syslog(idata->pamh, LOG_ERR, "Unmount of %s failed, %m", - pptr->dir); - return PAM_SESSION_ERR; - } else if (idata->flags & PAMNS_DEBUG) - pam_syslog(idata->pamh, LOG_DEBUG, "Unmount of %s succeeded", - pptr->dir); - } - } - - cleanup_tmpdirs(idata); - return 0; -} - - -#ifdef WITH_SELINUX -/* - * This function checks if the calling program has requested context - * change by calling setexeccon(). If context change is not requested - * then it does not make sense to polyinstantiate based on context. - * The return value from this function is used when selecting the - * polyinstantiation method. If context change is not requested then - * the polyinstantiation method is set to USER, even if the configuration - * file lists the method as "context" or "level". - */ -static int ctxt_based_inst_needed(void) -{ - security_context_t scon = NULL; - int rc = 0; - - rc = getexeccon(&scon); - if (rc < 0 || scon == NULL) - return 0; - else { - freecon(scon); - return 1; - } -} -#endif - - -static int get_user_data(struct instance_data *idata) -{ - int retval; - char *user_name; - struct passwd *pwd; - /* - * Lookup user and fill struct items - */ - retval = pam_get_item(idata->pamh, PAM_USER, (void*) &user_name ); - if ( user_name == NULL || retval != PAM_SUCCESS ) { - pam_syslog(idata->pamh, LOG_ERR, "Error recovering pam user name"); - return PAM_SESSION_ERR; - } - - pwd = pam_modutil_getpwnam(idata->pamh, user_name); - if (!pwd) { - pam_syslog(idata->pamh, LOG_ERR, "user unknown '%s'", user_name); - return PAM_USER_UNKNOWN; - } - - /* - * Add the user info to the instance data so we can refer to them later. - */ - idata->user[0] = 0; - strncat(idata->user, user_name, sizeof(idata->user) - 1); - idata->uid = pwd->pw_uid; - idata->gid = pwd->pw_gid; - - /* Fill in RUSER too */ - retval = pam_get_item(idata->pamh, PAM_RUSER, (void*) &user_name ); - if ( user_name != NULL && retval == PAM_SUCCESS && user_name[0] != '\0' ) { - strncat(idata->ruser, user_name, sizeof(idata->ruser) - 1); - pwd = pam_modutil_getpwnam(idata->pamh, user_name); - } else { - pwd = pam_modutil_getpwuid(idata->pamh, getuid()); - } - if (!pwd) { - pam_syslog(idata->pamh, LOG_ERR, "user unknown '%s'", user_name); - return PAM_USER_UNKNOWN; - } - user_name = pwd->pw_name; - - idata->ruser[0] = 0; - strncat(idata->ruser, user_name, sizeof(idata->ruser) - 1); - idata->ruid = pwd->pw_uid; - - return PAM_SUCCESS; -} - -/* - * Entry point from pam_open_session call. - */ -PAM_EXTERN int pam_sm_open_session(pam_handle_t *pamh, int flags UNUSED, - int argc, const char **argv) -{ - int i, retval; - struct instance_data idata; - enum unmnt_op unmnt = NO_UNMNT; - - /* init instance data */ - idata.flags = 0; - idata.polydirs_ptr = NULL; - idata.pamh = pamh; -#ifdef WITH_SELINUX - if (is_selinux_enabled()) - idata.flags |= PAMNS_SELINUX_ENABLED; - if (ctxt_based_inst_needed()) - idata.flags |= PAMNS_CTXT_BASED_INST; -#endif - - /* Parse arguments. */ - for (i = 0; i < argc; i++) { - if (strcmp(argv[i], "debug") == 0) - idata.flags |= PAMNS_DEBUG; - if (strcmp(argv[i], "gen_hash") == 0) - idata.flags |= PAMNS_GEN_HASH; - if (strcmp(argv[i], "ignore_config_error") == 0) - idata.flags |= PAMNS_IGN_CONFIG_ERR; - if (strcmp(argv[i], "ignore_instance_parent_mode") == 0) - idata.flags |= PAMNS_IGN_INST_PARENT_MODE; - if (strcmp(argv[i], "use_current_context") == 0) { - idata.flags |= PAMNS_USE_CURRENT_CONTEXT; - idata.flags |= PAMNS_CTXT_BASED_INST; - } - if (strcmp(argv[i], "use_default_context") == 0) { - idata.flags |= PAMNS_USE_DEFAULT_CONTEXT; - idata.flags |= PAMNS_CTXT_BASED_INST; - } - if (strcmp(argv[i], "unmnt_remnt") == 0) - unmnt = UNMNT_REMNT; - if (strcmp(argv[i], "unmnt_only") == 0) - unmnt = UNMNT_ONLY; - if (strcmp(argv[i], "require_selinux") == 0) { - if (~(idata.flags & PAMNS_SELINUX_ENABLED)) { - pam_syslog(idata.pamh, LOG_ERR, - "selinux_required option given and selinux is disabled"); - return PAM_SESSION_ERR; - } - } - } - if (idata.flags & PAMNS_DEBUG) - pam_syslog(idata.pamh, LOG_DEBUG, "open_session - start"); - - retval = get_user_data(&idata); - if (retval != PAM_SUCCESS) - return retval; - - /* - * Parse namespace configuration file which lists directories to - * polyinstantiate, directory where instance directories are to - * be created and the method used for polyinstantiation. - */ - retval = parse_config_file(&idata); - if (retval != PAM_SUCCESS) { - del_polydir_list(idata.polydirs_ptr); - return PAM_SESSION_ERR; - } - - if (idata.polydirs_ptr) { - retval = setup_namespace(&idata, unmnt); - if (idata.flags & PAMNS_DEBUG) { - if (retval) - pam_syslog(idata.pamh, LOG_DEBUG, - "namespace setup failed for pid %d", getpid()); - else - pam_syslog(idata.pamh, LOG_DEBUG, - "namespace setup ok for pid %d", getpid()); - } - } else if (idata.flags & PAMNS_DEBUG) - pam_syslog(idata.pamh, LOG_DEBUG, "Nothing to polyinstantiate"); - - if (retval != PAM_SUCCESS) - del_polydir_list(idata.polydirs_ptr); - return retval; -} - - -/* - * Entry point from pam_close_session call. - */ -PAM_EXTERN int pam_sm_close_session(pam_handle_t *pamh, int flags UNUSED, - int argc, const char **argv) -{ - int i, retval; - struct instance_data idata; - void *polyptr; - - /* init instance data */ - idata.flags = 0; - idata.polydirs_ptr = NULL; - idata.pamh = pamh; -#ifdef WITH_SELINUX - if (is_selinux_enabled()) - idata.flags |= PAMNS_SELINUX_ENABLED; - if (ctxt_based_inst_needed()) - idata.flags |= PAMNS_CTXT_BASED_INST; -#endif - - /* Parse arguments. */ - for (i = 0; i < argc; i++) { - if (strcmp(argv[i], "debug") == 0) - idata.flags |= PAMNS_DEBUG; - if (strcmp(argv[i], "ignore_config_error") == 0) - idata.flags |= PAMNS_IGN_CONFIG_ERR; - if (strcmp(argv[i], "no_unmount_on_close") == 0) - idata.flags |= PAMNS_NO_UNMOUNT_ON_CLOSE; - } - - if (idata.flags & PAMNS_DEBUG) - pam_syslog(idata.pamh, LOG_DEBUG, "close_session - start"); - - /* - * For certain trusted programs such as newrole, open session - * is called from a child process while the parent perfoms - * close session and pam end functions. For these commands - * pam_close_session should not perform the unmount of the - * polyinstantiatied directory because it will result in - * undoing of parents polyinstantiatiaion. These commands - * will invoke pam_namespace with the "no_unmount_on_close" - * argument. - */ - if (idata.flags & PAMNS_NO_UNMOUNT_ON_CLOSE) { - if (idata.flags & PAMNS_DEBUG) - pam_syslog(idata.pamh, LOG_DEBUG, "close_session - sucessful"); - return PAM_SUCCESS; - } - - retval = get_user_data(&idata); - if (retval != PAM_SUCCESS) - return retval; - - retval = pam_get_data(idata.pamh, NAMESPACE_POLYDIR_DATA, (const void **)&polyptr); - if (retval != PAM_SUCCESS || polyptr == NULL) - /* nothing to reset */ - return PAM_SUCCESS; - - idata.polydirs_ptr = polyptr; - - if (idata.flags & PAMNS_DEBUG) - pam_syslog(idata.pamh, LOG_DEBUG, "Resetting namespace for pid %d", - getpid()); - - retval = orig_namespace(&idata); - if (idata.flags & PAMNS_DEBUG) { - if (retval) - pam_syslog(idata.pamh, LOG_DEBUG, - "resetting namespace failed for pid %d", getpid()); - else - pam_syslog(idata.pamh, LOG_DEBUG, - "resetting namespace ok for pid %d", getpid()); - } - - pam_set_data(idata.pamh, NAMESPACE_POLYDIR_DATA, NULL, NULL); - - return PAM_SUCCESS; -} - -#ifdef PAM_STATIC - -/* static module data */ - -struct pam_module _pam_namespace_modstruct = { - "pam_namespace", - NULL, - NULL, - NULL, - pam_sm_open_session, - pam_sm_close_session, - NULL -}; -#endif |