database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-11-12 13:01:09 +03:00
Code Activity

Fix issues on unix with opening database files via symlinks that are not in the current working directory. And with nested symlinks.

Browse Source 
FossilOrigin-Name: 80398fd44fb232193450103808e1854e0eba5652
This commit is contained in:
dan
2016-01-25 17:04:48 +00:00
parent cc2fa4cf55
commit e88ec187cd
4 changed files with 215 additions and 79 deletions
Download Patch File Download Diff File Expand all files Collapse all files

154
src/os_unix.c
View File

@@ -149,6 +149,11 @@
*/
#define MAX_PATHNAME 512
/*
** Maximum supported symbolic links
*/
#define SQLITE_MAX_SYMLINKS 100
/* Always cast the getpid() return type for compatibility with
** kernel modules in VxWorks. */
#define osGetpid(X) (pid_t)getpid()
@@ -5927,52 +5932,22 @@ static int unixAccess(
return SQLITE_OK;
}
/*
** Turn a relative pathname into a full pathname. The relative path
** is stored as a nul-terminated string in the buffer pointed to by
** zPath.
** Buffer zOut contains a (possibly) relative pathname. Overwrite it with
** the corresponding full pathname.
**
** zOut points to a buffer of at least sqlite3_vfs.mxPathname bytes
** (in this case, MAX_PATHNAME bytes). The full-path is written to
** this buffer before returning.
** Parameter nOut is the allocated size of buffer zOut. nByte is the number
** of bytes in the nul-terminated string that it contains (not including
** the nul-terminator itself).
**
** Return SQLITE_OK if successful, or an SQLite error code otherwise.
*/
static int unixFullPathname(
sqlite3_vfs *pVfs, /* Pointer to vfs object */
const char *zPath, /* Possibly relative input path */
int nOut, /* Size of output buffer in bytes */
char *zOut /* Output buffer */
static int mkFullPathname(
const char *zPath, /* Use this path to log any errors */
char *zOut, /* IN/OUT: Buffer to modify */
int nByte, /* size of nul-terminated zOut in bytes */
int nOut /* Allocated size of buffer zOut */
){
int nByte;
/* It's odd to simulate an io-error here, but really this is just
** using the io-error infrastructure to test that SQLite handles this
** function failing. This function could fail if, for example, the
** current working directory has been unlinked.
*/
SimulateIOError( return SQLITE_ERROR );
assert( pVfs->mxPathname==MAX_PATHNAME );
UNUSED_PARAMETER(pVfs);
#if defined(HAVE_READLINK)
/* Attempt to resolve the path as if it were a symbolic link. If it is
** a symbolic link, the resolved path is stored in buffer zOut[]. Or, if
** the identified file is not a symbolic link or does not exist, then
** zPath is copied directly into zOut. Either way, nByte is left set to
** the size of the string copied into zOut[] in bytes. */
nByte = osReadlink(zPath, zOut, nOut-1);
if( nByte<0 ){
if( errno!=EINVAL && errno!=ENOENT ){
return unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zPath);
}
sqlite3_snprintf(nOut, zOut, "%s", zPath);
nByte = sqlite3Strlen30(zOut);
}else{
zOut[nByte] = '\0';
}
#endif
/* If buffer zOut[] now contains an absolute path there is nothing more
** to do. If it contains a relative path, do the following:
**
@@ -5989,6 +5964,7 @@ static int unixFullPathname(
** truncated to make it fit. This is Ok, as SQLite refuses to open any
** file for which this function returns a full path larger than (nOut-8)
** bytes in size. */
assert( nByte<nOut );
testcase( nByte==nOut-5 );
testcase( nByte==nOut-4 );
if( zOut[0]!='/' && nByte<nOut-4 ){
@@ -6008,6 +5984,100 @@ static int unixFullPathname(
return SQLITE_OK;
}
/*
** Turn a relative pathname into a full pathname. The relative path
** is stored as a nul-terminated string in the buffer pointed to by
** zPath.
**
** zOut points to a buffer of at least sqlite3_vfs.mxPathname bytes
** (in this case, MAX_PATHNAME bytes). The full-path is written to
** this buffer before returning.
*/
static int unixFullPathname(
sqlite3_vfs *pVfs, /* Pointer to vfs object */
const char *zPath, /* Possibly relative input path */
int nOut, /* Size of output buffer in bytes */
char *zOut /* Output buffer */
){
#if !defined(HAVE_READLINK)
sqlite3_snprintf(nOut, zOut, "%s", zIn);
nByte = sqlite3Strlen30(zOut);
return mkFullPathname(zPath, zOut, sqlite3Strlen30(zOut), nOut);
#else
int rc = SQLITE_OK;
int nByte;
int nLink = 0; /* Number of symbolic links followed so far */
int bLink; /* True for a symbolic link */
const char *zIn = zPath; /* Input path for each iteration of loop */
char *zDel = 0;
assert( pVfs->mxPathname==MAX_PATHNAME );
UNUSED_PARAMETER(pVfs);
/* It's odd to simulate an io-error here, but really this is just
** using the io-error infrastructure to test that SQLite handles this
** function failing. This function could fail if, for example, the
** current working directory has been unlinked.
*/
SimulateIOError( return SQLITE_ERROR );
do {
/* Attempt to resolve the path as if it were a symbolic link. If it is
** a symbolic link, the resolved path is stored in buffer zOut[]. Or, if
** the identified file is not a symbolic link or does not exist, then
** zPath is copied directly into zOut. Either way, nByte is left set to
** the size of the string copied into zOut[] in bytes. */
assert( (zDel==0 && zIn==zPath) || (zDel!=0 && zIn==zDel) );
if( zDel ){
assert( zIn==zDel );
sqlite3_snprintf(nOut, zDel, "%s", zOut);
}
nByte = osReadlink(zIn, zOut, nOut-1);
if( nByte<0 ){
if( errno!=EINVAL && errno!=ENOENT ){
rc = unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zPath);
}else{
sqlite3_snprintf(nOut, zOut, "%s", zIn);
nByte = sqlite3Strlen30(zOut);
}
bLink = 0;
}else if( ++nLink>SQLITE_MAX_SYMLINKS ){
sqlite3_log(SQLITE_CANTOPEN,
"too many symbolic links (max=%d)", SQLITE_MAX_SYMLINKS
);
rc = SQLITE_CANTOPEN_BKPT;
}else{
zOut[nByte] = '\0';
if( zOut[0]!='/' ){
int n;
for(n = sqlite3Strlen30(zIn); n>0 && zIn[n-1]!='/'; n--);
if( nByte+n+1>nOut ){
rc = SQLITE_CANTOPEN_BKPT;
}else{
memmove(&zOut[n], zOut, nByte+1);
memcpy(zOut, zIn, n);
nByte += n;
}
}
if( zDel==0 ){
zDel = sqlite3_malloc(nOut);
if( zDel==0 ) rc = SQLITE_NOMEM;
zIn = (const char*)zDel;
}
bLink = 1;
}
if( rc==SQLITE_OK ){
rc = mkFullPathname(zPath, zOut, nByte, nOut);
}
}while( bLink && rc==SQLITE_OK );
sqlite3_free(zDel);
return rc;
#endif /* HAVE_READLINK */
}
#ifndef SQLITE_OMIT_LOAD_EXTENSION
/*