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Simplify the unixFullpathname() function. This adds a dependency on lstat().

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FossilOrigin-Name: f71249d3db9242b8f38955db51a7a5789d002803
This commit is contained in:
dan
2016-01-25 18:05:49 +00:00
parent e88ec187cd
commit caf6b150a1
3 changed files with 60 additions and 94 deletions
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137
src/os_unix.c
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@@ -480,6 +480,8 @@ static struct unix_syscall {
#endif
#define osReadlink ((ssize_t(*)(const char*,char*,size_t))aSyscall[26].pCurrent)
{ "lstat", (sqlite3_syscall_ptr)lstat, 0 },
#define osLstat ((int(*)(const char*,struct stat*))aSyscall[27].pCurrent)
}; /* End of the overrideable system calls */
@@ -5933,54 +5935,24 @@ static int unixAccess(
}
/*
** Buffer zOut contains a (possibly) relative pathname. Overwrite it with
** the corresponding full pathname.
**
** 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 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 */
const char *zPath, /* Input path */
char *zOut, /* Output buffer */
int nOut /* Allocated size of buffer zOut */
){
/* If buffer zOut[] now contains an absolute path there is nothing more
** to do. If it contains a relative path, do the following:
**
** * move the relative path string so that it is at the end of th
** zOut[] buffer.
** * Call getcwd() to read the path of the current working directory
** into the start of the zOut[] buffer.
** * Append a '/' character to the cwd string and move the
** relative path back within the buffer so that it immediately
** follows the '/'.
**
** This code is written so that if the combination of the CWD and relative
** path are larger than the allocated size of zOut[] the CWD is silently
** 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 ){
int nCwd;
int nRem = nOut-nByte-1;
memmove(&zOut[nRem], zOut, nByte+1);
zOut[nRem-1] = '\0';
if( osGetcwd(zOut, nRem-1)==0 ){
int nPath = sqlite3Strlen30(zPath);
int iOff = 0;
if( zPath[0]!='/' ){
if( osGetcwd(zOut, nOut-2)==0 ){
return unixLogError(SQLITE_CANTOPEN_BKPT, "getcwd", zPath);
}
nCwd = sqlite3Strlen30(zOut);
assert( nCwd<=nRem-1 );
zOut[nCwd] = '/';
memmove(&zOut[nCwd+1], &zOut[nRem], nByte+1);
iOff = sqlite3Strlen30(zOut);
zOut[iOff++] = '/';
}
if( (iOff+nPath+1)>nOut ) return SQLITE_CANTOPEN_BKPT;
sqlite3_snprintf(nOut-iOff, &zOut[iOff], "%s", zPath);
return SQLITE_OK;
}
@@ -6000,13 +5972,11 @@ static int unixFullPathname(
char *zOut /* Output buffer */
){
#if !defined(HAVE_READLINK)
sqlite3_snprintf(nOut, zOut, "%s", zIn);
nByte = sqlite3Strlen30(zOut);
return mkFullPathname(zPath, zOut, sqlite3Strlen30(zOut), nOut);
return mkFullPathname(zPath, zOut, nOut);
#else
int rc = SQLITE_OK;
int nByte;
int nLink = 0; /* Number of symbolic links followed so far */
int nLink = 1; /* 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;
@@ -6023,55 +5993,54 @@ static int unixFullPathname(
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);
/* Call stat() on path zIn. Set bLink to true if the path is a symbolic
** link, or false otherwise. */
int bLink = 0;
struct stat buf;
if( osLstat(zIn, &buf)!=0 ){
if( errno!=ENOENT ){
rc = unixLogError(SQLITE_CANTOPEN_BKPT, "stat", zIn);
}
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;
}
}
bLink = S_ISLNK(buf.st_mode);
}
if( bLink ){
if( zDel==0 ){
zDel = sqlite3_malloc(nOut);
if( zDel==0 ) rc = SQLITE_NOMEM;
zIn = (const char*)zDel;
}else if( ++nLink>SQLITE_MAX_SYMLINKS ){
rc = SQLITE_CANTOPEN_BKPT;
}
bLink = 1;
if( rc==SQLITE_OK ){
nByte = osReadlink(zIn, zDel, nOut-1);
if( nByte<0 ){
rc = unixLogError(SQLITE_CANTOPEN_BKPT, "readlink", zIn);
}else if( zDel[0]!='/' ){
int n;
for(n = sqlite3Strlen30(zIn); n>0 && zIn[n-1]!='/'; n--);
if( nByte+n+1>nOut ){
rc = SQLITE_CANTOPEN_BKPT;
}else{
memmove(&zDel[n], zDel, nByte+1);
memcpy(zDel, zIn, n);
nByte += n;
}
zDel[nByte] = '\0';
}
}
zIn = zDel;
}
if( rc==SQLITE_OK ){
rc = mkFullPathname(zPath, zOut, nByte, nOut);
assert( zIn!=zOut || zIn[0]=='/' );
rc = mkFullPathname(zIn, zOut, nOut);
}
}while( bLink && rc==SQLITE_OK );
if( bLink==0 ) break;
zIn = zOut;
}while( rc==SQLITE_OK );
sqlite3_free(zDel);
return rc;
@@ -7574,7 +7543,7 @@ int sqlite3_os_init(void){
/* Double-check that the aSyscall[] array has been constructed
** correctly. See ticket [bb3a86e890c8e96ab] */
assert( ArraySize(aSyscall)==27 );
assert( ArraySize(aSyscall)==28 );
/* Register all VFSes defined in the aVfs[] array */
for(i=0; i<(sizeof(aVfs)/sizeof(sqlite3_vfs)); i++){