Revise the SQLITE_OPEN_NOFOLLOW so that it actually uses O_NOFOLLOW in the

open() system call.  This backs out the SQLITE_ACCESS_SYMLINK value but adds
the new SQLITE_OK_SYMLINK return code from the xFullPathname method of 
sqlite3_vfs when that routine resolves symbolic links. O_NOFOLLOW is always
included in open() system calls for journal files.

FossilOrigin-Name: 6a64fb6a2da6c98f1e87b55ad5689967e1db4eae2e08345471d95e28cd567e0f

1 files changed, 18 insertions, 24 deletions

diff --git a/src/os_unix.c b/src/os_unix.c
index 7217a5d5f..18f2afcb6 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3685,7 +3685,7 @@ static int openDirectory(const char *zFilename, int *pFd){
     if( zDirname[0]!='/' ) zDirname[0] = '.';
     zDirname[1] = 0;
   }
-  fd = robust_open(zDirname, O_RDONLY|O_BINARY, 0);
+  fd = robust_open(zDirname, O_RDONLY|O_BINARY|O_NOFOLLOW, 0);
   if( fd>=0 ){
     OSTRACE(("OPENDIR %-3d %s\n", fd, zDirname));
   }
@@ -4576,10 +4576,12 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
 
     if( pInode->bProcessLock==0 ){
       if( 0==sqlite3_uri_boolean(pDbFd->zPath, "readonly_shm", 0) ){
-        pShmNode->hShm = robust_open(zShm, O_RDWR|O_CREAT,(sStat.st_mode&0777));
+        pShmNode->hShm = robust_open(zShm, O_RDWR|O_CREAT|O_NOFOLLOW,
+                                     (sStat.st_mode&0777));
       }
       if( pShmNode->hShm<0 ){
-        pShmNode->hShm = robust_open(zShm, O_RDONLY, (sStat.st_mode&0777));
+        pShmNode->hShm = robust_open(zShm, O_RDONLY|O_NOFOLLOW,
+                                     (sStat.st_mode&0777));
         if( pShmNode->hShm<0 ){
           rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShm);
           goto shm_open_err;
@@ -5929,7 +5931,7 @@ static int unixOpen(
   unixFile *p = (unixFile *)pFile;
   int fd = -1;                   /* File descriptor returned by open() */
   int openFlags = 0;             /* Flags to pass to open() */
-  int eType = flags&0xFFFFFF00;  /* Type of file to open */
+  int eType = flags&0x0FFF00;  /* Type of file to open */
   int noLock;                    /* True to omit locking primitives */
   int rc = SQLITE_OK;            /* Function Return Code */
   int ctrlFlags = 0;             /* UNIXFILE_* flags */
@@ -6039,7 +6041,7 @@ static int unixOpen(
   if( isReadWrite ) openFlags |= O_RDWR;
   if( isCreate )    openFlags |= O_CREAT;
   if( isExclusive ) openFlags |= (O_EXCL|O_NOFOLLOW);
-  openFlags |= (O_LARGEFILE|O_BINARY);
+  openFlags |= (O_LARGEFILE|O_BINARY|O_NOFOLLOW);
 
   if( fd<0 ){
     mode_t openMode;              /* Permissions to create file with */
@@ -6251,25 +6253,15 @@ static int unixAccess(
   SimulateIOError( return SQLITE_IOERR_ACCESS; );
   assert( pResOut!=0 );
 
-  /* The spec says there are four possible values for flags.  But the
-  ** SQLITE_ACCESS_READ flag is never used */
-  assert( flags==SQLITE_ACCESS_EXISTS
-       || flags==SQLITE_ACCESS_READWRITE
-       || flags==SQLITE_ACCESS_SYMLINK );
+  /* The spec says there are three possible values for flags.  But only
+  ** two of them are actually used */
+  assert( flags==SQLITE_ACCESS_EXISTS || flags==SQLITE_ACCESS_READWRITE );
 
   if( flags==SQLITE_ACCESS_EXISTS ){
     struct stat buf;
     *pResOut = (0==osStat(zPath, &buf) && buf.st_size>0);
-  }else if( flags==SQLITE_ACCESS_READWRITE ){
-    *pResOut = osAccess(zPath, W_OK|R_OK)==0;
   }else{
-#if !defined(HAVE_LSTAT)
-    *pResOut = 0;
-#else
-    struct stat buf;
-    *pResOut = (0==osLstat(zPath, &buf) && S_ISLNK(buf.st_mode));
-#endif
-    assert( flags==SQLITE_ACCESS_SYMLINK );
+    *pResOut = osAccess(zPath, W_OK|R_OK)==0;
   }
   return SQLITE_OK;
 }
@@ -6321,7 +6313,7 @@ static int unixFullPathname(
 #else
   int rc = SQLITE_OK;
   int nByte;
-  int nLink = 1;                /* Number of symbolic links followed so far */
+  int nLink = 0;                /* Number of symbolic links followed so far */
   const char *zIn = zPath;      /* Input path for each iteration of loop */
   char *zDel = 0;
 
@@ -6350,10 +6342,11 @@ static int unixFullPathname(
     }
 
     if( bLink ){
+      nLink++;
       if( zDel==0 ){
         zDel = sqlite3_malloc(nOut);
         if( zDel==0 ) rc = SQLITE_NOMEM_BKPT;
-      }else if( ++nLink>SQLITE_MAX_SYMLINKS ){
+      }else if( nLink>=SQLITE_MAX_SYMLINKS ){
         rc = SQLITE_CANTOPEN_BKPT;
       }
 
@@ -6389,6 +6382,7 @@ static int unixFullPathname(
   }while( rc==SQLITE_OK );
 
   sqlite3_free(zDel);
+  if( rc==SQLITE_OK && nLink ) rc = SQLITE_OK_SYMLINK;
   return rc;
 #endif   /* HAVE_READLINK && HAVE_LSTAT */
 }
@@ -6874,7 +6868,7 @@ static int proxyCreateUnixFile(
   int fd = -1;
   unixFile *pNew;
   int rc = SQLITE_OK;
-  int openFlags = O_RDWR | O_CREAT;
+  int openFlags = O_RDWR | O_CREAT | O_NOFOLLOW;
   sqlite3_vfs dummyVfs;
   int terrno = 0;
   UnixUnusedFd *pUnused = NULL;
@@ -6904,7 +6898,7 @@ static int proxyCreateUnixFile(
     }
   }
   if( fd<0 ){
-    openFlags = O_RDONLY;
+    openFlags = O_RDONLY | O_NOFOLLOW;
     fd = robust_open(path, openFlags, 0);
     terrno = errno;
   }
@@ -7030,7 +7024,7 @@ static int proxyBreakConchLock(unixFile *pFile, uuid_t myHostID){
     goto end_breaklock;
   }
   /* write it out to the temporary break file */
-  fd = robust_open(tPath, (O_RDWR|O_CREAT|O_EXCL), 0);
+  fd = robust_open(tPath, (O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW), 0);
   if( fd<0 ){
     sqlite3_snprintf(sizeof(errmsg), errmsg, "create failed (%d)", errno);
     goto end_breaklock;