On Sun, Nov 14, 2010 at 3:06 PM, Gavin Atkinson <ga...@freebsd.org> wrote:
> On Sun, 14 Nov 2010, Ed Schouten wrote:
>> Author: ed
>> Date: Sun Nov 14 18:42:39 2010
>> New Revision: 215310
>> URL: http://svn.freebsd.org/changeset/base/215310
>>
>> Log:
>> Always set errno to a sane value when pututxline(3) fails.
>>
>> For example, it will now return ESRCH when trying to replace a
>> nonexistent entry with DEAD_PROCESS.
>>
>> Modified:
>> head/lib/libc/gen/pututxline.c
>>
>> Modified: head/lib/libc/gen/pututxline.c
>> ==============================================================================
>> --- head/lib/libc/gen/pututxline.c Sun Nov 14 18:24:12 2010
>> (r215309)
>> +++ head/lib/libc/gen/pututxline.c Sun Nov 14 18:42:39 2010
>> (r215310)
>> @@ -31,6 +31,7 @@ __FBSDID("$FreeBSD$");
>> #include <sys/endian.h>
>> #include <sys/stat.h>
>> #include <sys/uio.h>
>> +#include <errno.h>
>> #include <fcntl.h>
>> #include <stdio.h>
>> #include <string.h>
>> @@ -53,6 +54,7 @@ futx_open(const char *file)
>> /* Safety check: never use broken files. */
>> if (_fstat(fd, &sb) != -1 && sb.st_size % sizeof(struct futx) != 0) {
>> _close(fd);
>> + errno = EINVAL;
>> return (NULL);
>> }
>
> setutxdb(3) returns EFTYPE here, for the same error. Should this be the
> same?
>
>>
>> @@ -142,6 +144,7 @@ utx_active_remove(struct futx *fu)
>> }
>>
>> fclose(fp);
>> + errno = ESRCH;
>> return (1);
>> }
>
> These possible errors should probably also now be documented in
> pututxline(3).
I submitted another patch earlier to Ed that does this and a bit
more (attached). He was going to take a look at the patch and get back
to me (and I CCed Bruce Evans for additional comments), but please
feel free to chime in :).
Thanks,
-Garrett
Index: lib/libc/gen/getutxent.3
===================================================================
--- lib/libc/gen/getutxent.3 (revision 215314)
+++ lib/libc/gen/getutxent.3 (working copy)
@@ -367,16 +367,15 @@
.Dv NULL
when the provided
.Vt utmpx
-is invalid.
-This may be because
+is invalid, or
.Fa ut_type
-is invalid or
-.Fa ut_type
has a value of
.Dv DEAD_PROCESS
and an entry with an identifier with a value equal to the field
.Fa ut_id
-was not found.
+was not found; the global variable
+.Va errno
+is set to indicate the error.
.Pp
The
.Fn setutxdb
@@ -387,8 +386,26 @@
is set to indicate the error.
.Sh ERRORS
In addition to the error conditions described in
+.Xr fdopen 3 ,
.Xr fopen 3 ,
+.Xr fseek 3 ,
+.Xr open 3 ,
the
+.Fn pututxline
+function can generate the following errors:
+.Bl -tag -width Er
+.It Bq Er ESRCH
+The value of
+.Fa ut_type
+is DEAD_PROCESS, and the process entry could not be found.
+.It Bq Er EINVAL
+The value of
+.Fa ut_type
+is not supported by this implementation.
+.El
+In addition to the error conditions described in
+.Xr fopen 3 ,
+the
.Fn setutxdb
function can generate the following errors:
.Bl -tag -width Er
Index: lib/libc/gen/getutxent.c
===================================================================
--- lib/libc/gen/getutxent.c (revision 215314)
+++ lib/libc/gen/getutxent.c (working copy)
@@ -112,22 +112,22 @@
if (udb == UTXDB_LOG) {
uint16_t len;
- if (fread(&len, sizeof len, 1, uf) != 1)
+ if (fread(&len, sizeof(len), 1, uf) != 1)
return (-1);
len = be16toh(len);
if (len > sizeof *fu) {
/* Forward compatibility. */
- if (fread(fu, sizeof *fu, 1, uf) != 1)
+ if (fread(fu, sizeof(*fu), 1, uf) != 1)
return (-1);
- fseek(uf, len - sizeof *fu, SEEK_CUR);
+ fseek(uf, len - sizeof(*fu), SEEK_CUR);
} else {
/* Partial record. */
- memset(fu, 0, sizeof *fu);
+ memset(fu, 0, sizeof(*fu));
if (fread(fu, len, 1, uf) != 1)
return (-1);
}
} else {
- if (fread(fu, sizeof *fu, 1, uf) != 1)
+ if (fread(fu, sizeof(*fu), 1, uf) != 1)
return (-1);
}
return (0);
@@ -163,7 +163,8 @@
case LOGIN_PROCESS:
case DEAD_PROCESS:
if (memcmp(fu.fu_id, id->ut_id,
- MIN(sizeof fu.fu_id, sizeof id->ut_id)) == 0)
+ MIN(sizeof(fu.fu_id), sizeof(id->ut_id))) ==
+ 0)
goto found;
}
break;
@@ -191,7 +192,8 @@
case USER_PROCESS:
case LOGIN_PROCESS:
if (strncmp(fu.fu_line, line->ut_line,
- MIN(sizeof fu.fu_line, sizeof line->ut_line)) == 0)
+ MIN(sizeof(fu.fu_line), sizeof(line->ut_line))) ==
+ 0)
goto found;
break;
}
@@ -212,7 +214,7 @@
switch (fu.fu_type) {
case USER_PROCESS:
- if (strncmp(fu.fu_user, user, sizeof fu.fu_user) == 0)
+ if (strncmp(fu.fu_user, user, sizeof(fu.fu_user)) == 0)
goto found;
break;
}
Index: lib/libc/gen/pututxline.c
===================================================================
--- lib/libc/gen/pututxline.c (revision 215314)
+++ lib/libc/gen/pututxline.c (working copy)
@@ -43,9 +43,9 @@
static FILE *
futx_open(const char *file)
{
+ struct stat sb;
+ FILE *fp;
int fd;
- FILE *fp;
- struct stat sb;
fd = _open(file, O_CREAT|O_RDWR|O_EXLOCK, 0644);
if (fd < 0)
@@ -54,7 +54,7 @@
/* Safety check: never use broken files. */
if (_fstat(fd, &sb) != -1 && sb.st_size % sizeof(struct futx) != 0) {
_close(fd);
- errno = EINVAL;
+ errno = EFTYPE;
return (NULL);
}
@@ -63,16 +63,16 @@
_close(fd);
return (NULL);
}
-
return (fp);
}
static int
utx_active_add(const struct futx *fu)
{
+ struct futx fe;
FILE *fp;
- struct futx fe;
off_t partial = -1;
+ int error, ret;
/*
* Register user login sessions. Overwrite entries of sessions
@@ -80,16 +80,17 @@
*/
fp = futx_open(_PATH_UTX_ACTIVE);
if (fp == NULL)
- return (1);
- while (fread(&fe, sizeof fe, 1, fp) == 1) {
+ return (-1);
+ while (fread(&fe, sizeof(fe), 1, fp) == 1) {
switch (fe.fu_type) {
case USER_PROCESS:
case INIT_PROCESS:
case LOGIN_PROCESS:
case DEAD_PROCESS:
/* Overwrite when ut_id matches. */
- if (memcmp(fu->fu_id, fe.fu_id, sizeof fe.fu_id) == 0) {
- fseeko(fp, -(off_t)sizeof fe, SEEK_CUR);
+ if (memcmp(fu->fu_id, fe.fu_id, sizeof(fe.fu_id)) ==
+ 0) {
+ ret = fseeko(fp, -(off_t)sizeof(fe), SEEK_CUR);
goto exact;
}
if (fe.fu_type != DEAD_PROCESS)
@@ -97,55 +98,73 @@
/* FALLTHROUGH */
default:
/* Allow us to overwrite unused records. */
- if (partial == -1)
- partial = ftello(fp) - (off_t)sizeof fe;
+ if (partial == -1) {
+ partial = ftello(fp);
+ /*
+ * Distinguish errors from valid values so we
+ * don't overwrite good data by accident.
+ */
+ if (partial != -1)
+ partial -= (off_t)sizeof(fe);
+ }
break;
}
}
-
+
/*
* No exact match found. Use the partial match. If no partial
* match was found, just append a new record.
*/
if (partial != -1)
- fseeko(fp, partial, SEEK_SET);
+ ret = fseeko(fp, partial, SEEK_SET);
exact:
- fwrite(fu, sizeof *fu, 1, fp);
+ if (ret == -1)
+ error = errno;
+ else if (fwrite(fu, sizeof(*fu), 1, fp) < 1)
+ error = errno;
+ else
+ error = 0;
fclose(fp);
- return (0);
+ errno = error;
+ return (error == 0 ? 0 : 1);
}
static int
utx_active_remove(struct futx *fu)
{
+ struct futx fe;
FILE *fp;
- struct futx fe;
+ int error, ret;
/*
* Remove user login sessions, having the same ut_id.
*/
fp = futx_open(_PATH_UTX_ACTIVE);
if (fp == NULL)
- return (1);
- while (fread(&fe, sizeof fe, 1, fp) == 1) {
+ return (-1);
+ error = ESRCH;
+ ret = -1;
+ while (fread(&fe, sizeof(fe), 1, fp) == 1 && ret != 0)
switch (fe.fu_type) {
case USER_PROCESS:
case INIT_PROCESS:
case LOGIN_PROCESS:
- if (memcmp(fu->fu_id, fe.fu_id, sizeof fe.fu_id) != 0)
+ if (memcmp(fu->fu_id, fe.fu_id, sizeof(fe.fu_id)) != 0)
continue;
/* Terminate session. */
- fseeko(fp, -(off_t)sizeof fe, SEEK_CUR);
- fwrite(fu, sizeof *fu, 1, fp);
- fclose(fp);
- return (0);
+ if (fseeko(fp, -(off_t)sizeof(fe), SEEK_CUR) == -1)
+ error = errno;
+ else if (fwrite(fu, sizeof(*fu), 1, fp) < 1)
+ error = errno;
+ else
+ ret = 0;
+
}
- }
fclose(fp);
- errno = ESRCH;
- return (1);
+ errno = error;
+ return (ret);
}
static void
@@ -158,9 +177,12 @@
static int
utx_lastlogin_add(const struct futx *fu)
{
+ struct futx fe;
FILE *fp;
- struct futx fe;
+ int error, ret;
+ ret = 0;
+
/*
* Write an entry to lastlogin. Overwrite the entry if the
* current user already has an entry. If not, append a new
@@ -168,25 +190,31 @@
*/
fp = futx_open(_PATH_UTX_LASTLOGIN);
if (fp == NULL)
- return (1);
+ return (-1);
while (fread(&fe, sizeof fe, 1, fp) == 1) {
if (strncmp(fu->fu_user, fe.fu_user, sizeof fe.fu_user) != 0)
continue;
-
+
/* Found a previous lastlogin entry for this user. */
- fseeko(fp, -(off_t)sizeof fe, SEEK_CUR);
+ ret = fseeko(fp, -(off_t)sizeof fe, SEEK_CUR);
break;
}
- fwrite(fu, sizeof *fu, 1, fp);
+ if (ret == -1)
+ error = errno;
+ else if (fwrite(fu, sizeof *fu, 1, fp) < 1) {
+ error = errno;
+ ret = -1;
+ }
fclose(fp);
- return (0);
+ errno = error;
+ return (ret);
}
static void
utx_lastlogin_upgrade(void)
{
+ struct stat sb;
int fd;
- struct stat sb;
fd = _open(_PATH_UTX_LASTLOGIN, O_RDWR, 0644);
if (fd < 0)
@@ -205,9 +233,9 @@
static int
utx_log_add(const struct futx *fu)
{
- int fd;
+ struct iovec vec[2];
+ int error, fd;
uint16_t l;
- struct iovec vec[2];
/*
* Append an entry to the log file. We only need to append
@@ -215,19 +243,23 @@
* zero-bytes. Prepend a length field, indicating the length of
* the record, excluding the length field itself.
*/
- for (l = sizeof *fu; l > 0 && ((const char *)fu)[l - 1] == '\0'; l--);
+ for (l = sizeof(*fu); l > 0 && ((const char *)fu)[l - 1] == '\0'; l--) ;
vec[0].iov_base = &l;
- vec[0].iov_len = sizeof l;
+ vec[0].iov_len = sizeof(l);
vec[1].iov_base = __DECONST(void *, fu);
vec[1].iov_len = l;
l = htobe16(l);
fd = _open(_PATH_UTX_LOG, O_CREAT|O_WRONLY|O_APPEND, 0644);
if (fd < 0)
- return (1);
- _writev(fd, vec, 2);
+ return (-1);
+ if (_writev(fd, vec, 2) == -1)
+ error = errno;
+ else
+ error = 0;
_close(fd);
- return (0);
+ errno = error;
+ return (error == 0 ? 0 : 1);
}
struct utmpx *
@@ -237,7 +269,7 @@
int bad = 0;
utx_to_futx(utmpx, &fu);
-
+
switch (fu.fu_type) {
case BOOT_TIME:
case SHUTDOWN_TIME:
@@ -267,6 +299,7 @@
return (NULL);
break;
default:
+ errno = EINVAL;
return (NULL);
}
Index: lib/libc/gen/utxdb.c
===================================================================
--- lib/libc/gen/utxdb.c (revision 215314)
+++ lib/libc/gen/utxdb.c (working copy)
@@ -132,9 +132,8 @@
ut = calloc(1, sizeof *ut);
if (ut == NULL)
return (NULL);
- } else {
+ } else
memset(ut, 0, sizeof *ut);
- }
switch (fu->fu_type) {
case BOOT_TIME:
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