diff options
Diffstat (limited to 'src/os_unix.c')
| -rw-r--r-- | src/os_unix.c | 154 |
1 files changed, 112 insertions, 42 deletions
diff --git a/src/os_unix.c b/src/os_unix.c index ee9b55674..9cd1fa19a 100644 --- a/src/os_unix.c +++ b/src/os_unix.c @@ -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 /* |