dumputils.c

PostgreSQL7.4.6 for Linux

/*-------------------------------------------------------------------------
 *
 * Utility routines for SQL dumping
 *	Basically this is stuff that is useful in both pg_dump and pg_dumpall.
 *
 *
 * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * $Header: /cvsroot/pgsql/src/bin/pg_dump/dumputils.c,v 1.9 2003/08/14 14:19:11 tgl Exp $
 *
 *-------------------------------------------------------------------------
 */

#include "postgres_fe.h"

#include "dumputils.h"

#include "parser/keywords.h"


#define supports_grant_options(version) ((version) >= 70400)

static bool parseAclArray(const char *acls, char ***itemarray, int *nitems);
static bool parseAclItem(const char *item, const char *type, const char *name,
			 int remoteVersion,
			 PQExpBuffer grantee, PQExpBuffer grantor,
			 PQExpBuffer privs, PQExpBuffer privswgo);
static char *copyAclUserName(PQExpBuffer output, char *input);
static void AddAcl(PQExpBuffer aclbuf, const char *keyword);


/*
 *	Quotes input string if it's not a legitimate SQL identifier as-is.
 *
 *	Note that the returned string must be used before calling fmtId again,
 *	since we re-use the same return buffer each time.  Non-reentrant but
 *	avoids memory leakage.
 */
const char *
fmtId(const char *rawid)
{
	static PQExpBuffer id_return = NULL;
	const char *cp;
	bool		need_quotes = false;

	if (id_return)				/* first time through? */
		resetPQExpBuffer(id_return);
	else
		id_return = createPQExpBuffer();

	/*
	 * These checks need to match the identifier production in scan.l.
	 * Don't use islower() etc.
	 */

	if (ScanKeywordLookup(rawid))
		need_quotes = true;
	/* slightly different rules for first character */
	else if (!((rawid[0] >= 'a' && rawid[0] <= 'z') || rawid[0] == '_'))
		need_quotes = true;
	else
	{
		/* otherwise check the entire string */
		for (cp = rawid; *cp; cp++)
		{
			if (!((*cp >= 'a' && *cp <= 'z')
				  || (*cp >= '0' && *cp <= '9')
				  || (*cp == '_')))
			{
				need_quotes = true;
				break;
			}
		}
	}

	if (!need_quotes)
	{
		/* no quoting needed */
		appendPQExpBufferStr(id_return, rawid);
	}
	else
	{
		appendPQExpBufferChar(id_return, '\"');
		for (cp = rawid; *cp; cp++)
		{
			/*
			 * Did we find a double-quote in the string? Then make this a
			 * double double-quote per SQL99. Before, we put in a
			 * backslash/double-quote pair. - thomas 2000-08-05
			 */
			if (*cp == '\"')
				appendPQExpBufferChar(id_return, '\"');
			appendPQExpBufferChar(id_return, *cp);
		}
		appendPQExpBufferChar(id_return, '\"');
	}

	return id_return->data;
}


/*
 * Convert a string value to an SQL string literal and append it to
 * the given buffer.
 *
 * Special characters are escaped. Quote mark ' goes to '' per SQL
 * standard, other stuff goes to \ sequences.  If escapeAll is false,
 * whitespace characters are not escaped (tabs, newlines, etc.).  This
 * is appropriate for dump file output.
 */
void
appendStringLiteral(PQExpBuffer buf, const char *str, bool escapeAll)
{
	appendPQExpBufferChar(buf, '\'');
	while (*str)
	{
		char		ch = *str++;

		if (ch == '\\' || ch == '\'')
		{
			appendPQExpBufferChar(buf, ch);		/* double these */
			appendPQExpBufferChar(buf, ch);
		}
		else if ((unsigned char) ch < (unsigned char) ' ' &&
				 (escapeAll
				  || (ch != '\t' && ch != '\n' && ch != '\v' && ch != '\f' && ch != '\r')
				  ))
		{
			/*
			 * generate octal escape for control chars other than
			 * whitespace
			 */
			appendPQExpBufferChar(buf, '\\');
			appendPQExpBufferChar(buf, ((ch >> 6) & 3) + '0');
			appendPQExpBufferChar(buf, ((ch >> 3) & 7) + '0');
			appendPQExpBufferChar(buf, (ch & 7) + '0');
		}
		else
			appendPQExpBufferChar(buf, ch);
	}
	appendPQExpBufferChar(buf, '\'');
}


/*
 * Convert backend's version string into a number.
 */
int
parse_version(const char *versionString)
{
	int			cnt;
	int			vmaj,
				vmin,
				vrev;

	cnt = sscanf(versionString, "%d.%d.%d", &vmaj, &vmin, &vrev);

	if (cnt < 2)
		return -1;

	if (cnt == 2)
		vrev = 0;

	return (100 * vmaj + vmin) * 100 + vrev;
}


/*
 * Build GRANT/REVOKE command(s) for an object.
 *
 *	name: the object name, in the form to use in the commands (already quoted)
 *	type: the object type (as seen in GRANT command: must be one of
 *		TABLE, FUNCTION, LANGUAGE, or SCHEMA, or DATABASE)
 *	acls: the ACL string fetched from the database
 *	owner: username of object owner (will be passed through fmtId), or NULL
 *	remoteVersion: version of database
 *
 * Returns TRUE if okay, FALSE if could not parse the acl string.
 * The resulting commands (if any) are appended to the contents of 'sql'.
 *
 * Note: beware of passing fmtId() result as 'name', since this routine
 * uses fmtId() internally.
 */
bool
buildACLCommands(const char *name, const char *type,
				 const char *acls, const char *owner,
				 int remoteVersion,
				 PQExpBuffer sql)
{
	char	  **aclitems;
	int			naclitems;
	int			i;
	PQExpBuffer grantee,
				grantor,
				privs,
				privswgo;
	PQExpBuffer firstsql,
				secondsql;
	bool		found_owner_privs = false;

	if (strlen(acls) == 0)
		return true;			/* object has default permissions */

	if (!parseAclArray(acls, &aclitems, &naclitems))
	{
		if (aclitems)
			free(aclitems);
		return false;
	}

	grantee = createPQExpBuffer();
	grantor = createPQExpBuffer();
	privs = createPQExpBuffer();
	privswgo = createPQExpBuffer();

	/*
	 * At the end, these two will be pasted together to form the result.
	 * But the owner privileges need to go before the other ones to keep
	 * the dependencies valid.	In recent versions this is normally the
	 * case, but in old versions they come after the PUBLIC privileges and
	 * that results in problems if we need to run REVOKE on the owner
	 * privileges.
	 */
	firstsql = createPQExpBuffer();
	secondsql = createPQExpBuffer();

	/*
	 * Always start with REVOKE ALL FROM PUBLIC, so that we don't have to
	 * wire-in knowledge about the default public privileges for different
	 * kinds of objects.
	 */
	appendPQExpBuffer(firstsql, "REVOKE ALL ON %s %s FROM PUBLIC;\n",
					  type, name);

	/* Scan individual ACL items */
	for (i = 0; i < naclitems; i++)
	{
		if (!parseAclItem(aclitems[i], type, name, remoteVersion,
						  grantee, grantor, privs, privswgo))
			return false;

		if (grantor->len == 0 && owner)
			printfPQExpBuffer(grantor, "%s", owner);

		if (privs->len > 0 || privswgo->len > 0)
		{
			if (owner
				&& strcmp(grantee->data, owner) == 0
				&& strcmp(grantor->data, owner) == 0)
			{
				found_owner_privs = true;

				/*
				 * For the owner, the default privilege level is ALL WITH
				 * GRANT OPTION (only ALL prior to 7.4).
				 */
				if (supports_grant_options(remoteVersion)
					? strcmp(privswgo->data, "ALL") != 0
					: strcmp(privs->data, "ALL") != 0)
				{
					appendPQExpBuffer(firstsql, "REVOKE ALL ON %s %s FROM %s;\n",
									  type, name,
									  fmtId(grantee->data));
					if (privs->len > 0)
						appendPQExpBuffer(firstsql, "GRANT %s ON %s %s TO %s;\n",
										  privs->data, type, name,
										  fmtId(grantee->data));
					if (privswgo->len > 0)
						appendPQExpBuffer(firstsql, "GRANT %s ON %s %s TO %s WITH GRANT OPTION;\n",
										  privswgo->data, type, name,
										  fmtId(grantee->data));
				}
			}
			else
			{
				/*
				 * Otherwise can assume we are starting from no privs.
				 */
				if (grantor->len > 0
					&& (!owner || strcmp(owner, grantor->data) != 0))
					appendPQExpBuffer(secondsql, "SET SESSION AUTHORIZATION %s;\n",
									  fmtId(grantor->data));

				if (privs->len > 0)
				{
					appendPQExpBuffer(secondsql, "GRANT %s ON %s %s TO ",
									  privs->data, type, name);
					if (grantee->len == 0)
						appendPQExpBuffer(secondsql, "PUBLIC;\n");
					else if (strncmp(grantee->data, "group ",
									 strlen("group ")) == 0)
						appendPQExpBuffer(secondsql, "GROUP %s;\n",
								fmtId(grantee->data + strlen("group ")));
					else
						appendPQExpBuffer(secondsql, "%s;\n", fmtId(grantee->data));
				}
				if (privswgo->len > 0)
				{
					appendPQExpBuffer(secondsql, "GRANT %s ON %s %s TO ",