vfs_afsacl.c

samba-3.0.22.tar.gz 编译smb服务器的源码

/* 
 * Convert AFS acls to NT acls and vice versa.
 *
 * Copyright (C) Volker Lendecke, 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 2 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, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "includes.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_VFS

#include <afs/stds.h>
#include <afs/afs.h>
#include <afs/auth.h>
#include <afs/venus.h>
#include <afs/prs_fs.h>

#define MAXSIZE 2048

extern const DOM_SID global_sid_World;
extern const DOM_SID global_sid_Builtin_Administrators;
extern const DOM_SID global_sid_Builtin_Backup_Operators;
extern const DOM_SID global_sid_Authenticated_Users;
extern const DOM_SID global_sid_NULL;

static char space_replacement = '%';

/* Do we expect SIDs as pts names? */
static BOOL sidpts;

extern int afs_syscall(int, char *, int, char *, int);

struct afs_ace {
	BOOL positive;
	char *name;
	DOM_SID sid;
	enum SID_NAME_USE type;
	uint32 rights;
	struct afs_ace *next;
};

struct afs_acl {
	TALLOC_CTX *ctx;
	int type;
	int num_aces;
	struct afs_ace *acelist;
};

struct afs_iob {
	char *in, *out;
	uint16 in_size, out_size;
};


static BOOL init_afs_acl(struct afs_acl *acl)
{
	ZERO_STRUCT(*acl);
	acl->ctx = talloc_init("afs_acl");
	if (acl->ctx == NULL) {
		DEBUG(10, ("Could not init afs_acl"));
		return False;
	}
	return True;
}

static void free_afs_acl(struct afs_acl *acl)
{
	if (acl->ctx != NULL)
		talloc_destroy(acl->ctx);
	acl->ctx = NULL;
	acl->num_aces = 0;
	acl->acelist = NULL;
}

static struct afs_ace *clone_afs_ace(TALLOC_CTX *mem_ctx, struct afs_ace *ace)
{
	struct afs_ace *result = TALLOC_P(mem_ctx, struct afs_ace);

	if (result == NULL)
		return NULL;

	*result = *ace;

	result->next = NULL;
	result->name = talloc_strdup(mem_ctx, ace->name);

	if (result->name == NULL) {
		return NULL;
	}

	return result;
}
	
static struct afs_ace *new_afs_ace(TALLOC_CTX *mem_ctx,
				   BOOL positive,
				   const char *name, uint32 rights)
{
	DOM_SID sid;
	enum SID_NAME_USE type;
	struct afs_ace *result;

	if (strcmp(name, "system:administrators") == 0) {

		sid_copy(&sid, &global_sid_Builtin_Administrators);
		type = SID_NAME_ALIAS;

	} else if (strcmp(name, "system:anyuser") == 0) {

		sid_copy(&sid, &global_sid_World);
		type = SID_NAME_ALIAS;

	} else if (strcmp(name, "system:authuser") == 0) {

		sid_copy(&sid, &global_sid_Authenticated_Users);
		type = SID_NAME_WKN_GRP;

	} else if (strcmp(name, "system:backup") == 0) {

		sid_copy(&sid, &global_sid_Builtin_Backup_Operators);
		type = SID_NAME_ALIAS;

	} else if (sidpts) {
		/* All PTS users/groups are expressed as SIDs */

		sid_copy(&sid, &global_sid_NULL);
		type = SID_NAME_UNKNOWN;

		if (string_to_sid(&sid, name)) {
			fstring user, domain;
			/* We have to find the type, look up the SID */
			lookup_sid(&sid, domain, user, &type);
		}

	} else {

		fstring domain, uname;
		char *p;

		p = strchr_m(name, lp_winbind_separator());
		if (p != NULL) {
			*p = '\\';
		}

		if (!lookup_name(name, LOOKUP_NAME_FULL,
				 domain, uname, &sid, &type)) {
			DEBUG(10, ("Could not find AFS user %s\n", name));

			sid_copy(&sid, &global_sid_NULL);
			type = SID_NAME_UNKNOWN;

		}
	}

	result = TALLOC_P(mem_ctx, struct afs_ace);

	if (result == NULL) {
		DEBUG(0, ("Could not talloc AFS ace\n"));
		return NULL;
	}

	result->name = talloc_strdup(mem_ctx, name);
	if (result->name == NULL) {
		DEBUG(0, ("Could not talloc AFS ace name\n"));
		return NULL;
	}

	result->sid = sid;
	result->type = type;

	result->positive = positive;
	result->rights = rights;

	return result;
}

static void add_afs_ace(struct afs_acl *acl,
			BOOL positive,
			const char *name, uint32 rights)
{
	struct afs_ace *ace;

	for (ace = acl->acelist; ace != NULL; ace = ace->next) {
		if ((ace->positive == positive) &&
		    (strequal(ace->name, name))) {
			ace->rights |= rights;
			return;
		}
	}

	ace = new_afs_ace(acl->ctx, positive, name, rights);

	ace->next = acl->acelist;
	acl->acelist = ace;

	acl->num_aces += 1;

	DEBUG(10, ("add_afs_ace: Added %s entry for %s with rights %d\n",
		   ace->positive?"positive":"negative",
		   ace->name, ace->rights));

	return;
}

/* AFS ACLs in string form are a long string of fields delimited with \n.
 *
 * First line:  Number of positive entries
 * Second line: Number of negative entries
 * Third and following lines: The entries themselves
 *
 * An ACE is a line of two fields, delimited by \t.
 *
 * First field:  Name
 * Second field: Rights
 */

static BOOL parse_afs_acl(struct afs_acl *acl, const char *acl_str)
{
	int nplus, nminus;
	int aces;

	char str[MAXSIZE+1];
	char *p = str;

	strncpy(str, acl_str, MAXSIZE);

	if (sscanf(p, "%d", &nplus) != 1)
		return False;

	DEBUG(10, ("Found %d positive entries\n", nplus));

	if ((p = strchr(p, '\n')) == NULL)
		return False;
	p += 1;

	if (sscanf(p, "%d", &nminus) != 1)
		return False;
	
	DEBUG(10, ("Found %d negative entries\n", nminus));

	if ((p = strchr(p, '\n')) == NULL)
		return False;
	p += 1;

	for (aces = nplus+nminus; aces > 0; aces--)
	{

		const char *namep;
		fstring name;
		uint32 rights;
		char *space;

		namep = p;

		if ((p = strchr(p, '\t')) == NULL)
			return False;
		*p = '\0';
		p += 1;

		if (sscanf(p, "%d", &rights) != 1)
			return False;

		if ((p = strchr(p, '\n')) == NULL)
			return False;
		p += 1;

		fstrcpy(name, namep);

		while ((space = strchr_m(name, space_replacement)) != NULL)
			*space = ' ';

		add_afs_ace(acl, nplus>0, name, rights);

		nplus -= 1;
	}

	return True;
}

static BOOL unparse_afs_acl(struct afs_acl *acl, char *acl_str)
{
	/* TODO: String length checks!!!! */

	int positives = 0;
	int negatives = 0;
	fstring line;

	*acl_str = 0;

	struct afs_ace *ace = acl->acelist;

	while (ace != NULL) {
		if (ace->positive)
			positives++;
		else
			negatives++;
		ace = ace->next;
	}

	fstr_sprintf(line, "%d\n", positives);
	safe_strcat(acl_str, line, MAXSIZE);

	fstr_sprintf(line, "%d\n", negatives);
	safe_strcat(acl_str, line, MAXSIZE);

	ace = acl->acelist;

	while (ace != NULL) {
		fstr_sprintf(line, "%s\t%d\n", ace->name, ace->rights);
		safe_strcat(acl_str, line, MAXSIZE);
		ace = ace->next;
	}
	return True;
}

static uint32 afs_to_nt_file_rights(uint32 rights)
{
	uint32 result = 0;

	if (rights & PRSFS_READ)
		result |= FILE_READ_DATA | FILE_READ_EA | 
			FILE_EXECUTE | FILE_READ_ATTRIBUTES |
			READ_CONTROL_ACCESS | SYNCHRONIZE_ACCESS;

	if (rights & PRSFS_WRITE)
		result |= FILE_WRITE_DATA | FILE_WRITE_ATTRIBUTES |
			FILE_WRITE_EA | FILE_APPEND_DATA;

	if (rights & PRSFS_LOCK)
		result |= WRITE_OWNER_ACCESS;

	if (rights & PRSFS_DELETE)
		result |= DELETE_ACCESS;

	return result;
}

static void afs_to_nt_dir_rights(uint32 afs_rights, uint32 *nt_rights,
				 uint8 *flag)
{
	*nt_rights = 0;
	*flag = SEC_ACE_FLAG_OBJECT_INHERIT |
		SEC_ACE_FLAG_CONTAINER_INHERIT;

	if (afs_rights & PRSFS_INSERT)
		*nt_rights |= FILE_ADD_FILE | FILE_ADD_SUBDIRECTORY;

	if (afs_rights & PRSFS_LOOKUP)
		*nt_rights |= FILE_READ_DATA | FILE_READ_EA | 
			FILE_EXECUTE | FILE_READ_ATTRIBUTES |
			READ_CONTROL_ACCESS | SYNCHRONIZE_ACCESS;

	if (afs_rights & PRSFS_WRITE)
		*nt_rights |= FILE_WRITE_ATTRIBUTES | FILE_WRITE_DATA |
			FILE_APPEND_DATA | FILE_WRITE_EA;

	if ((afs_rights & (PRSFS_INSERT|PRSFS_LOOKUP|PRSFS_DELETE)) ==
	    (PRSFS_INSERT|PRSFS_LOOKUP|PRSFS_DELETE))
		*nt_rights |= FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA |
			GENERIC_WRITE_ACCESS;

	if (afs_rights & PRSFS_DELETE)
		*nt_rights |= DELETE_ACCESS;

	if (afs_rights & PRSFS_ADMINISTER)
		*nt_rights |= FILE_DELETE_CHILD | WRITE_DAC_ACCESS |
			WRITE_OWNER_ACCESS;

	if ( (afs_rights & PRSFS_LOOKUP) ==
	     (afs_rights & (PRSFS_LOOKUP|PRSFS_READ)) ) {
		/* Only lookup right */
		*flag = SEC_ACE_FLAG_CONTAINER_INHERIT;
	}

	return;
}

#define AFS_FILE_RIGHTS (PRSFS_READ|PRSFS_WRITE|PRSFS_LOCK)
#define AFS_DIR_RIGHTS  (PRSFS_INSERT|PRSFS_LOOKUP|PRSFS_DELETE|PRSFS_ADMINISTER)

static void split_afs_acl(struct afs_acl *acl,
			  struct afs_acl *dir_acl,
			  struct afs_acl *file_acl)
{
	struct afs_ace *ace;

	init_afs_acl(dir_acl);
	init_afs_acl(file_acl);

	for (ace = acl->acelist; ace != NULL; ace = ace->next) {
		if (ace->rights & AFS_FILE_RIGHTS) {
			add_afs_ace(file_acl, ace->positive, ace->name,
				    ace->rights & AFS_FILE_RIGHTS);
		}

		if (ace->rights & AFS_DIR_RIGHTS) {
			add_afs_ace(dir_acl, ace->positive, ace->name,
				    ace->rights & AFS_DIR_RIGHTS);
		}
	}
	return;
}

static BOOL same_principal(struct afs_ace *x, struct afs_ace *y)
{
	return ( (x->positive == y->positive) &&
		 (sid_compare(&x->sid, &y->sid) == 0) );
}

static void merge_afs_acls(struct afs_acl *dir_acl,
			   struct afs_acl *file_acl,
			   struct afs_acl *target)
{
	struct afs_ace *ace;

	init_afs_acl(target);

	for (ace = dir_acl->acelist; ace != NULL; ace = ace->next) {
		struct afs_ace *file_ace;
		BOOL found = False;

		for (file_ace = file_acl->acelist;
		     file_ace != NULL;
		     file_ace = file_ace->next) {
			if (!same_principal(ace, file_ace))
				continue;

			add_afs_ace(target, ace->positive, ace->name,
				    ace->rights | file_ace->rights);
			found = True;
			break;
		}
		if (!found)
			add_afs_ace(target, ace->positive, ace->name,
				    ace->rights);
	}

	for (ace = file_acl->acelist; ace != NULL; ace = ace->next) {
		struct afs_ace *dir_ace;
		BOOL already_seen = False;

		for (dir_ace = dir_acl->acelist;
		     dir_ace != NULL;
		     dir_ace = dir_ace->next) {
			if (!same_principal(ace, dir_ace))
				continue;
			already_seen = True;
			break;
		}
		if (!already_seen)
			add_afs_ace(target, ace->positive, ace->name,
				    ace->rights);
	}
}

#define PERMS_READ   0x001200a9
#define PERMS_CHANGE 0x001301bf
#define PERMS_FULL   0x001f01ff

static struct static_dir_ace_mapping {
	uint8 type;
	uint8 flags;
	uint32 mask;
	uint32 afs_rights;
} ace_mappings[] = {

	/* Full control */
	{ 0, SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT,
	  PERMS_FULL, 127 /* rlidwka */ },

	/* Change (write) */
	{ 0, SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT,
	  PERMS_CHANGE, 63 /* rlidwk */ },

	/* Read (including list folder content) */
	{ 0, SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT,
	  PERMS_READ, 9 /* rl */ },

	/* Read without list folder content -- same as "l" */
	{ 0, SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT,
	  0x00120089, 8 /* l */ },

	/* some stupid workaround for preventing fallbacks */ 	
	{ 0, 0x3, 0x0012019F, 9 /* rl */ },
	{ 0, 0x13, PERMS_FULL, 127 /* full */ },
	
	/* read, delete and execute access plus synchronize */
	{ 0, 0x3, 0x001300A9, 9 /* should be rdl, set to rl */},
	/* classical read list */
	{ 0, 0x13, 0x001200A9, 9 /* rl */},
	/* almost full control, no delete */
	{ 0, 0x13, PERMS_CHANGE, 63 /* rwidlk */},

	/* List folder */
	{ 0, SEC_ACE_FLAG_CONTAINER_INHERIT,
	  PERMS_READ, 8 /* l */ },

	/* FULL without inheritance -- in all cases here we also get
	   the corresponding INHERIT_ONLY ACE in the same ACL */
	{ 0, 0, PERMS_FULL, 127 /* rlidwka */ },

	/* FULL inherit only -- counterpart to previous one */
	{ 0, SEC_ACE_FLAG_OBJECT_INHERIT|SEC_ACE_FLAG_CONTAINER_INHERIT|SEC_ACE_FLAG_INHERIT_ONLY,
	  PERMS_FULL | GENERIC_RIGHT_WRITE_ACCESS, 127 /* rlidwka */ },

	/* CHANGE without inheritance -- in all cases here we also get
	   the corresponding INHERIT_ONLY ACE in the same ACL */
	{ 0, 0, PERMS_CHANGE, 63 /* rlidwk */ },