diff options
Diffstat (limited to 'source3/lib/sharesec.c')
| -rw-r--r-- | source3/lib/sharesec.c | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/source3/lib/sharesec.c b/source3/lib/sharesec.c new file mode 100644 index 0000000000..33f66ca47f --- /dev/null +++ b/source3/lib/sharesec.c @@ -0,0 +1,400 @@ +/* + * Unix SMB/Netbios implementation. + * SEC_DESC handling functions + * Copyright (C) Jeremy R. Allison 1995-2003. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "includes.h" + +/******************************************************************* + Create the share security tdb. + ********************************************************************/ + +static struct db_context *share_db; /* used for share security descriptors */ +#define SHARE_DATABASE_VERSION_V1 1 +#define SHARE_DATABASE_VERSION_V2 2 /* version id in little endian. */ + +/* Map generic permissions to file object specific permissions */ + +extern const struct generic_mapping file_generic_mapping; + +static int delete_fn(struct db_record *rec, void *priv) +{ + rec->delete_rec(rec); + return 0; +} + +static bool share_info_db_init(void) +{ + const char *vstring = "INFO/version"; + int32 vers_id; + + if (share_db != NULL) { + return True; + } + + share_db = db_open(NULL, state_path("share_info.tdb"), 0, + TDB_DEFAULT, O_RDWR|O_CREAT, 0600); + if (share_db == NULL) { + DEBUG(0,("Failed to open share info database %s (%s)\n", + state_path("share_info.tdb"), strerror(errno) )); + return False; + } + + vers_id = dbwrap_fetch_int32(share_db, vstring); + if (vers_id == SHARE_DATABASE_VERSION_V2) { + return true; + } + + if (share_db->transaction_start(share_db) != 0) { + DEBUG(0, ("transaction_start failed\n")); + TALLOC_FREE(share_db); + return false; + } + + vers_id = dbwrap_fetch_int32(share_db, vstring); + if (vers_id == SHARE_DATABASE_VERSION_V2) { + /* + * Race condition + */ + if (share_db->transaction_cancel(share_db)) { + smb_panic("transaction_cancel failed"); + } + return true; + } + + /* Cope with byte-reversed older versions of the db. */ + if ((vers_id == SHARE_DATABASE_VERSION_V1) || (IREV(vers_id) == SHARE_DATABASE_VERSION_V1)) { + /* Written on a bigendian machine with old fetch_int code. Save as le. */ + + if (dbwrap_store_int32(share_db, vstring, + SHARE_DATABASE_VERSION_V2) != 0) { + DEBUG(0, ("dbwrap_store_int32 failed\n")); + goto cancel; + } + vers_id = SHARE_DATABASE_VERSION_V2; + } + + if (vers_id != SHARE_DATABASE_VERSION_V2) { + int ret; + ret = share_db->traverse(share_db, delete_fn, NULL); + if (ret < 0) { + DEBUG(0, ("traverse failed\n")); + goto cancel; + } + if (dbwrap_store_int32(share_db, vstring, + SHARE_DATABASE_VERSION_V2) != 0) { + DEBUG(0, ("dbwrap_store_int32 failed\n")); + goto cancel; + } + } + + if (share_db->transaction_commit(share_db) != 0) { + DEBUG(0, ("transaction_commit failed\n")); + return false; + } + + return true; + + cancel: + if (share_db->transaction_cancel(share_db)) { + smb_panic("transaction_cancel failed"); + } + + return false; +} + +/******************************************************************* + Fake up a Everyone, default access as a default. + def_access is a GENERIC_XXX access mode. + ********************************************************************/ + +SEC_DESC *get_share_security_default( TALLOC_CTX *ctx, size_t *psize, uint32 def_access) +{ + SEC_ACCESS sa; + SEC_ACE ace; + SEC_ACL *psa = NULL; + SEC_DESC *psd = NULL; + uint32 spec_access = def_access; + + se_map_generic(&spec_access, &file_generic_mapping); + + init_sec_access(&sa, def_access | spec_access ); + init_sec_ace(&ace, &global_sid_World, SEC_ACE_TYPE_ACCESS_ALLOWED, sa, 0); + + if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, 1, &ace)) != NULL) { + psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1, + SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, + psa, psize); + } + + if (!psd) { + DEBUG(0,("get_share_security: Failed to make SEC_DESC.\n")); + return NULL; + } + + return psd; +} + +/******************************************************************* + Pull a security descriptor from the share tdb. + ********************************************************************/ + +SEC_DESC *get_share_security( TALLOC_CTX *ctx, const char *servicename, + size_t *psize) +{ + char *key; + SEC_DESC *psd = NULL; + TDB_DATA data; + NTSTATUS status; + + if (!share_info_db_init()) { + return NULL; + } + + if (!(key = talloc_asprintf(ctx, "SECDESC/%s", servicename))) { + DEBUG(0, ("talloc_asprintf failed\n")); + return NULL; + } + + data = dbwrap_fetch_bystring(share_db, talloc_tos(), key); + + TALLOC_FREE(key); + + if (data.dptr == NULL) { + return get_share_security_default(ctx, psize, + GENERIC_ALL_ACCESS); + } + + status = unmarshall_sec_desc(ctx, data.dptr, data.dsize, &psd); + + TALLOC_FREE(data.dptr); + + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0, ("unmarshall_sec_desc failed: %s\n", + nt_errstr(status))); + return NULL; + } + + if (psd) + *psize = ndr_size_security_descriptor(psd, 0); + + return psd; +} + +/******************************************************************* + Store a security descriptor in the share db. + ********************************************************************/ + +bool set_share_security(const char *share_name, SEC_DESC *psd) +{ + TALLOC_CTX *frame; + char *key; + bool ret = False; + TDB_DATA blob; + NTSTATUS status; + + if (!share_info_db_init()) { + return False; + } + + frame = talloc_stackframe(); + + status = marshall_sec_desc(frame, psd, &blob.dptr, &blob.dsize); + + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0, ("marshall_sec_desc failed: %s\n", + nt_errstr(status))); + goto out; + } + + if (!(key = talloc_asprintf(frame, "SECDESC/%s", share_name))) { + DEBUG(0, ("talloc_asprintf failed\n")); + goto out; + } + + status = dbwrap_trans_store(share_db, string_term_tdb_data(key), blob, + TDB_REPLACE); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(1, ("set_share_security: Failed to store secdesc for " + "%s: %s\n", share_name, nt_errstr(status))); + goto out; + } + + DEBUG(5,("set_share_security: stored secdesc for %s\n", share_name )); + ret = True; + + out: + TALLOC_FREE(frame); + return ret; +} + +/******************************************************************* + Delete a security descriptor. +********************************************************************/ + +bool delete_share_security(const char *servicename) +{ + TDB_DATA kbuf; + char *key; + NTSTATUS status; + + if (!(key = talloc_asprintf(talloc_tos(), "SECDESC/%s", + servicename))) { + return False; + } + kbuf = string_term_tdb_data(key); + + status = dbwrap_trans_delete(share_db, kbuf); + if (!NT_STATUS_IS_OK(status)) { + DEBUG(0, ("delete_share_security: Failed to delete entry for " + "share %s: %s\n", servicename, nt_errstr(status))); + return False; + } + + return True; +} + +/******************************************************************* + Can this user access with share with the required permissions ? +********************************************************************/ + +bool share_access_check(const NT_USER_TOKEN *token, const char *sharename, + uint32 desired_access) +{ + uint32 granted; + NTSTATUS status; + SEC_DESC *psd = NULL; + size_t sd_size; + bool ret = True; + + psd = get_share_security(talloc_tos(), sharename, &sd_size); + + if (!psd) { + return True; + } + + ret = se_access_check(psd, token, desired_access, &granted, &status); + + TALLOC_FREE(psd); + + return ret; +} + +/*************************************************************************** + Parse the contents of an acl string from a usershare file. +***************************************************************************/ + +bool parse_usershare_acl(TALLOC_CTX *ctx, const char *acl_str, SEC_DESC **ppsd) +{ + size_t s_size = 0; + const char *pacl = acl_str; + int num_aces = 0; + SEC_ACE *ace_list = NULL; + SEC_ACL *psa = NULL; + SEC_DESC *psd = NULL; + size_t sd_size = 0; + int i; + + *ppsd = NULL; + + /* If the acl string is blank return "Everyone:R" */ + if (!*acl_str) { + SEC_DESC *default_psd = get_share_security_default(ctx, &s_size, GENERIC_READ_ACCESS); + if (!default_psd) { + return False; + } + *ppsd = default_psd; + return True; + } + + num_aces = 1; + + /* Add the number of ',' characters to get the number of aces. */ + num_aces += count_chars(pacl,','); + + ace_list = TALLOC_ARRAY(ctx, SEC_ACE, num_aces); + if (!ace_list) { + return False; + } + + for (i = 0; i < num_aces; i++) { + SEC_ACCESS sa; + uint32 g_access; + uint32 s_access; + DOM_SID sid; + char *sidstr; + enum security_ace_type type = SEC_ACE_TYPE_ACCESS_ALLOWED; + + if (!next_token_talloc(ctx, &pacl, &sidstr, ":")) { + DEBUG(0,("parse_usershare_acl: malformed usershare acl looking " + "for ':' in string '%s'\n", pacl)); + return False; + } + + if (!string_to_sid(&sid, sidstr)) { + DEBUG(0,("parse_usershare_acl: failed to convert %s to sid.\n", + sidstr )); + return False; + } + + switch (*pacl) { + case 'F': /* Full Control, ie. R+W */ + case 'f': /* Full Control, ie. R+W */ + s_access = g_access = GENERIC_ALL_ACCESS; + break; + case 'R': /* Read only. */ + case 'r': /* Read only. */ + s_access = g_access = GENERIC_READ_ACCESS; + break; + case 'D': /* Deny all to this SID. */ + case 'd': /* Deny all to this SID. */ + type = SEC_ACE_TYPE_ACCESS_DENIED; + s_access = g_access = GENERIC_ALL_ACCESS; + break; + default: + DEBUG(0,("parse_usershare_acl: unknown acl type at %s.\n", + pacl )); + return False; + } + + pacl++; + if (*pacl && *pacl != ',') { + DEBUG(0,("parse_usershare_acl: bad acl string at %s.\n", + pacl )); + return False; + } + pacl++; /* Go past any ',' */ + + se_map_generic(&s_access, &file_generic_mapping); + init_sec_access(&sa, g_access | s_access ); + init_sec_ace(&ace_list[i], &sid, type, sa, 0); + } + + if ((psa = make_sec_acl(ctx, NT4_ACL_REVISION, num_aces, ace_list)) != NULL) { + psd = make_sec_desc(ctx, SECURITY_DESCRIPTOR_REVISION_1, + SEC_DESC_SELF_RELATIVE, NULL, NULL, NULL, + psa, &sd_size); + } + + if (!psd) { + DEBUG(0,("parse_usershare_acl: Failed to make SEC_DESC.\n")); + return False; + } + + *ppsd = psd; + return True; +} |