Properly styleify utmpx code and document error codes in man page.

Submitted by:	Garrett Cooper

4 files changed, 107 insertions, 56 deletions

diff --git a/lib/libc/gen/getutxent.3 b/lib/libc/gen/getutxent.3
index 7337853..c60d42f 100644
--- a/lib/libc/gen/getutxent.3
+++ b/lib/libc/gen/getutxent.3
@@ -367,16 +367,15 @@ It returns
 .Dv NULL
 when the provided
 .Vt utmpx
-is invalid.
-This may be because
-.Fa ut_type
-is invalid or
+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
@@ -387,6 +386,24 @@ Otherwise, -1 is returned and the global variable
 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
diff --git a/lib/libc/gen/getutxent.c b/lib/libc/gen/getutxent.c
index 654a634..556df56 100644
--- a/lib/libc/gen/getutxent.c
+++ b/lib/libc/gen/getutxent.c
@@ -112,22 +112,22 @@ getfutxent(struct futx *fu)
 	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 @@ getutxid(const struct utmpx *id)
 			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 @@ getutxline(const struct utmpx *line)
 		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 @@ getutxuser(const char *user)
 
 		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;
 		}
diff --git a/lib/libc/gen/pututxline.c b/lib/libc/gen/pututxline.c
index 5a9bab9..731817f 100644
--- a/lib/libc/gen/pututxline.c
+++ b/lib/libc/gen/pututxline.c
@@ -43,9 +43,9 @@ __FBSDID("$FreeBSD$");
 static FILE *
 futx_open(const char *file)
 {
-	int fd;
-	FILE *fp;
 	struct stat sb;
+	FILE *fp;
+	int fd;
 
 	fd = _open(file, O_CREAT|O_RDWR|O_EXLOCK, 0644);
 	if (fd < 0)
@@ -54,7 +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;
+		errno = EFTYPE;
 		return (NULL);
 	}
 	
@@ -63,16 +63,16 @@ futx_open(const char *file)
 		_close(fd);
 		return (NULL);
 	}
-
 	return (fp);
 }
 
 static int
 utx_active_add(const struct futx *fu)
 {
-	FILE *fp;
 	struct futx fe;
+	FILE *fp;
 	off_t partial = -1;
+	int error, ret;
 
 	/*
 	 * Register user login sessions.  Overwrite entries of sessions
@@ -80,16 +80,17 @@ utx_active_add(const struct futx *fu)
 	 */
 	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 @@ utx_active_add(const struct futx *fu)
 			/* 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)
 {
-	FILE *fp;
 	struct futx fe;
+	FILE *fp;
+	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
@@ -158,8 +177,11 @@ utx_active_purge(void)
 static int
 utx_lastlogin_add(const struct futx *fu)
 {
-	FILE *fp;
 	struct futx fe;
+	FILE *fp;
+	int error, ret;
+
+	ret = 0;
 
 	/*
 	 * Write an entry to lastlogin.  Overwrite the entry if the
@@ -168,25 +190,31 @@ utx_lastlogin_add(const struct futx *fu)
 	 */
 	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)
 {
-	int fd;
 	struct stat sb;
+	int fd;
 
 	fd = _open(_PATH_UTX_LASTLOGIN, O_RDWR, 0644);
 	if (fd < 0)
@@ -205,9 +233,9 @@ utx_lastlogin_upgrade(void)
 static int
 utx_log_add(const struct futx *fu)
 {
-	int fd;
-	uint16_t l;
 	struct iovec vec[2];
+	int error, fd;
+	uint16_t l;
 
 	/*
 	 * Append an entry to the log file.  We only need to append
@@ -215,19 +243,23 @@ utx_log_add(const struct futx *fu)
 	 * 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 @@ pututxline(const struct utmpx *utmpx)
 	int bad = 0;
 
 	utx_to_futx(utmpx, &fu);
-	
+
 	switch (fu.fu_type) {
 	case BOOT_TIME:
 	case SHUTDOWN_TIME:
@@ -267,6 +299,7 @@ pututxline(const struct utmpx *utmpx)
 			return (NULL);
 		break;
 	default:
+		errno = EINVAL;
 		return (NULL);
 	}
 
diff --git a/lib/libc/gen/utxdb.c b/lib/libc/gen/utxdb.c
index 6a85c05..743629d 100644
--- a/lib/libc/gen/utxdb.c
+++ b/lib/libc/gen/utxdb.c
@@ -132,9 +132,8 @@ futx_to_utx(const struct futx *fu)
 		ut = calloc(1, sizeof *ut);
 		if (ut == NULL)
 			return (NULL);
-	} else {
+	} else
 		memset(ut, 0, sizeof *ut);
-	}
 
 	switch (fu->fu_type) {
 	case BOOT_TIME: