Author: ian
Date: Thu Jul 26 18:34:38 2018
New Revision: 336746
URL: https://svnweb.freebsd.org/changeset/base/336746
Log:
Make pw_scan(3) more compatible with getpwent(3) et. al. when processing
data from /etc/passwd rather than /etc/master.passwd.
The libc getpwent(3) and related functions automatically read master.passwd
when run by root, or passwd when run by a non-root user. When run by non-
root, getpwent() copes with the missing data by setting the corresponding
fields in the passwd struct to known values (zeroes for numbers, or a
pointer to an empty string for literals). When libutil's pw_scan(3) was
used to parse a line without the root-accessible data, it was leaving
garbage in the corresponding fields.
These changes rename the static pw_init() function used by getpwent() and
friends to __pw_initpwd(), and move it into pw_scan.c so that common init
code can be shared between libc and libutil. pw_scan(3) now calls
__pw_initpwd() before __pw_scan(), just like the getpwent() family does, so
that reading an arbitrary passwd file in either format and parsing it with
pw_scan(3) returns the same results as getpwent(3) would.
This also adds a new pw_initpwd(3) function to libutil, so that code which
creates passwd structs from scratch in some manner that doesn't involve
pw_scan() can initialize the struct to the values expected by lots of
existing code, which doesn't expect to encounter NULL pointers or garbage
values in some fields.
Modified:
head/lib/libc/gen/Symbol.map
head/lib/libc/gen/getpwent.c
head/lib/libc/gen/pw_scan.c
head/lib/libc/gen/pw_scan.h
head/lib/libutil/libutil.h
head/lib/libutil/pw_util.3
head/lib/libutil/pw_util.c
Modified: head/lib/libc/gen/Symbol.map
==============================================================================
--- head/lib/libc/gen/Symbol.map Thu Jul 26 17:52:57 2018
(r336745)
+++ head/lib/libc/gen/Symbol.map Thu Jul 26 18:34:38 2018
(r336746)
@@ -510,6 +510,7 @@ FBSDprivate_1.0 {
__opendir2;
__pause;
_pause;
+ __pw_initpwd; /* Used by (at least) libutil */
__pw_scan; /* Used by (at least) libutil */
__raise;
_raise;
Modified: head/lib/libc/gen/getpwent.c
==============================================================================
--- head/lib/libc/gen/getpwent.c Thu Jul 26 17:52:57 2018
(r336745)
+++ head/lib/libc/gen/getpwent.c Thu Jul 26 18:34:38 2018
(r336746)
@@ -96,8 +96,6 @@ int __pw_match_entry(const char *, size_t, enum nss_lo
const char *, uid_t);
int __pw_parse_entry(char *, size_t, struct passwd *, int, int *errnop);
-static void pwd_init(struct passwd *);
-
union key {
const char *name;
uid_t uid;
@@ -527,7 +525,7 @@ getpwent_r(struct passwd *pwd, char *buffer, size_t bu
};
int rv, ret_errno;
- pwd_init(pwd);
+ __pw_initpwd(pwd);
ret_errno = 0;
*result = NULL;
rv = _nsdispatch(result, dtab, NSDB_PASSWD, "getpwent_r", defaultsrc,
@@ -566,7 +564,7 @@ getpwnam_r(const char *name, struct passwd *pwd, char
};
int rv, ret_errno;
- pwd_init(pwd);
+ __pw_initpwd(pwd);
ret_errno = 0;
*result = NULL;
rv = _nsdispatch(result, dtab, NSDB_PASSWD, "getpwnam_r", defaultsrc,
@@ -605,7 +603,7 @@ getpwuid_r(uid_t uid, struct passwd *pwd, char *buffer
};
int rv, ret_errno;
- pwd_init(pwd);
+ __pw_initpwd(pwd);
ret_errno = 0;
*result = NULL;
rv = _nsdispatch(result, dtab, NSDB_PASSWD, "getpwuid_r", defaultsrc,
@@ -617,23 +615,6 @@ getpwuid_r(uid_t uid, struct passwd *pwd, char *buffer
}
-static void
-pwd_init(struct passwd *pwd)
-{
- static char nul[] = "";
-
- memset(pwd, 0, sizeof(*pwd));
- pwd->pw_uid = (uid_t)-1; /* Considered least likely to lead to */
- pwd->pw_gid = (gid_t)-1; /* a security issue. */
- pwd->pw_name = nul;
- pwd->pw_passwd = nul;
- pwd->pw_class = nul;
- pwd->pw_gecos = nul;
- pwd->pw_dir = nul;
- pwd->pw_shell = nul;
-}
-
-
static struct passwd pwd;
static char *pwd_storage;
static size_t pwd_storage_size;
@@ -1614,7 +1595,7 @@ compat_redispatch(struct compat_state *st, enum nss_lo
for (i = 0; i < (int)(nitems(dtab) - 1); i++)
dtab[i].mdata = (void *)lookup_how;
more:
- pwd_init(pwd);
+ __pw_initpwd(pwd);
switch (lookup_how) {
case nss_lt_all:
rv = _nsdispatch(&discard, dtab, NSDB_PASSWD_COMPAT,
Modified: head/lib/libc/gen/pw_scan.c
==============================================================================
--- head/lib/libc/gen/pw_scan.c Thu Jul 26 17:52:57 2018 (r336745)
+++ head/lib/libc/gen/pw_scan.c Thu Jul 26 18:34:38 2018 (r336746)
@@ -65,6 +65,22 @@ __FBSDID("$FreeBSD$");
*/
static int pw_big_ids_warning = 0;
+void
+__pw_initpwd(struct passwd *pwd)
+{
+ static char nul[] = "";
+
+ memset(pwd, 0, sizeof(*pwd));
+ pwd->pw_uid = (uid_t)-1; /* Considered least likely to lead to */
+ pwd->pw_gid = (gid_t)-1; /* a security issue. */
+ pwd->pw_name = nul;
+ pwd->pw_passwd = nul;
+ pwd->pw_class = nul;
+ pwd->pw_gecos = nul;
+ pwd->pw_dir = nul;
+ pwd->pw_shell = nul;
+}
+
int
__pw_scan(char *bp, struct passwd *pw, int flags)
{
Modified: head/lib/libc/gen/pw_scan.h
==============================================================================
--- head/lib/libc/gen/pw_scan.h Thu Jul 26 17:52:57 2018 (r336745)
+++ head/lib/libc/gen/pw_scan.h Thu Jul 26 18:34:38 2018 (r336746)
@@ -35,4 +35,5 @@
#define _PWSCAN_MASTER 0x01
#define _PWSCAN_WARN 0x02
+extern void __pw_initpwd(struct passwd *);
extern int __pw_scan(char *, struct passwd *, int);
Modified: head/lib/libutil/libutil.h
==============================================================================
--- head/lib/libutil/libutil.h Thu Jul 26 17:52:57 2018 (r336745)
+++ head/lib/libutil/libutil.h Thu Jul 26 18:34:38 2018 (r336746)
@@ -155,6 +155,7 @@ int pw_edit(int _notsetuid);
int pw_equal(const struct passwd *_pw1, const struct passwd *_pw2);
void pw_fini(void);
int pw_init(const char *_dir, const char *_master);
+void pw_initpwd(struct passwd *_pw);
char *pw_make(const struct passwd *_pw);
char *pw_make_v7(const struct passwd *_pw);
int pw_mkdb(const char *_user);
Modified: head/lib/libutil/pw_util.3
==============================================================================
--- head/lib/libutil/pw_util.3 Thu Jul 26 17:52:57 2018 (r336745)
+++ head/lib/libutil/pw_util.3 Thu Jul 26 18:34:38 2018 (r336746)
@@ -24,7 +24,7 @@
.\"
.\" $FreeBSD$
.\"
-.Dd July 02, 2015
+.Dd July 26, 2018
.Dt PW_UTIL 3
.Os
.Sh NAME
@@ -59,6 +59,8 @@
.Fn pw_fini "void"
.Ft int
.Fn pw_init "const char *dir" const char *master"
+.Ft void
+.Fn pw_initpwd "struct passwd *pw"
.Ft "char *"
.Fn pw_make "const struct passwd *pw"
.Ft "char *"
@@ -179,7 +181,7 @@ if any.
.Pp
The
.Fn pw_init
-initialize the static variable representing the path a password file.
+initializes the static variable representing the path to a password file.
.Fa dir
is the directory where the password file is located.
If set to
@@ -192,6 +194,18 @@ If set to
.Dv NULL?
it will default to
.Pa master.passwd
+.Pp
+The
+.Fn pw_initpwd
+function initializes the
+.Vt passwd
+struct to canonical values.
+The entire structure is zeroed, then
+.Va pw_uid
+and
+.Va pw_gid
+are set to -1, and all string pointers are set to point at
+an internally-defined zero-length string.
.Pp
The
.Fn pw_make
Modified: head/lib/libutil/pw_util.c
==============================================================================
--- head/lib/libutil/pw_util.c Thu Jul 26 17:52:57 2018 (r336745)
+++ head/lib/libutil/pw_util.c Thu Jul 26 18:34:38 2018 (r336746)
@@ -652,8 +652,16 @@ pw_dup(const struct passwd *pw)
#include "pw_scan.h"
/*
- * Wrapper around an internal libc function
+ * Wrapper around some internal libc functions.
*/
+
+void
+pw_initpwd(struct passwd *pw)
+{
+
+ __pw_initpwd(pw);
+}
+
struct passwd *
pw_scan(const char *line, int flags)
{
@@ -662,6 +670,7 @@ pw_scan(const char *line, int flags)
if ((bp = strdup(line)) == NULL)
return (NULL);
+ __pw_initpwd(&pw);
if (!__pw_scan(bp, &pw, flags)) {
free(bp);
return (NULL);
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