Thanks for the feedback, here's an updated diff that eliminates
pwcache.h, gracefully handles table allocation failure and massages
the comments to be a bit more general.
I can take a look at supporting arbitrary length names in the future.
- todd
Index: include/pwd.h
===================================================================
RCS file: /cvs/src/include/pwd.h,v
retrieving revision 1.25
diff -u -p -u -r1.25 pwd.h
--- include/pwd.h 9 Mar 2017 10:13:03 -0000 1.25
+++ include/pwd.h 10 Sep 2018 00:46:44 -0000
@@ -106,7 +106,8 @@ void endpwent(void);
#endif
#if __BSD_VISIBLE
int setpassent(int);
-char *user_from_uid(uid_t, int);
+int uid_from_user(const char *, uid_t *);
+const char *user_from_uid(uid_t, int);
char *bcrypt_gensalt(u_int8_t);
char *bcrypt(const char *, const char *);
int bcrypt_newhash(const char *, int, char *, size_t);
Index: include/grp.h
===================================================================
RCS file: /cvs/src/include/grp.h,v
retrieving revision 1.12
diff -u -p -u -r1.12 grp.h
--- include/grp.h 31 Aug 2014 04:04:38 -0000 1.12
+++ include/grp.h 10 Sep 2018 00:46:44 -0000
@@ -70,7 +70,8 @@ int getgrnam_r(const char *, struct gr
#endif
#if __BSD_VISIBLE
int setgroupent(int);
-char *group_from_gid(gid_t, int);
+int gid_from_group(const char *, gid_t *);
+const char *group_from_gid(gid_t, int);
#endif
__END_DECLS
Index: lib/libc/gen/pwcache.3
===================================================================
RCS file: /cvs/src/lib/libc/gen/pwcache.3,v
retrieving revision 1.13
diff -u -p -u -r1.13 pwcache.3
--- lib/libc/gen/pwcache.3 26 Mar 2016 14:36:37 -0000 1.13
+++ lib/libc/gen/pwcache.3 10 Sep 2018 00:46:44 -0000
@@ -32,14 +32,20 @@
.Os
.Sh NAME
.Nm user_from_uid ,
+.Nm uid_from_user ,
.Nm group_from_gid
+.Nm gid_from_group
.Nd cache password and group entries
.Sh SYNOPSIS
-.In grp.h
.In pwd.h
-.Ft char *
+.Ft int
+.Fn uid_from_user "const char *name" "uid_t *uid"
+.Ft const char *
.Fn user_from_uid "uid_t uid" "int nouser"
-.Ft char *
+.In grp.h
+.Ft int
+.Fn gid_from_group "const char *name" "gid_t *gid"
+.Ft const char *
.Fn group_from_gid "gid_t gid" "int nogroup"
.Sh DESCRIPTION
The
@@ -60,6 +66,22 @@ unless the argument
is non-zero, in which case a null pointer is returned.
.Pp
The
+.Fn uid_from_user
+function returns the uid associated with the argument
+.Fa name .
+The uid is cached so that multiple calls with the same
+.Fa name
+do not require additional calls to
+.Xr getpwnam 3 .
+If there is no uid associated with the
+.Fa name ,
+the
+.Fn uid_from_user
+function returns -1; otherwise it stores the uid at the location pointed to by
+.Fa uid
+and returns 0.
+.Pp
+The
.Fn group_from_gid
function returns the group name associated with the argument
.Fa gid .
@@ -75,6 +97,22 @@ to a string representation of the
unless the argument
.Fa nogroup
is non-zero, in which case a null pointer is returned.
+.Pp
+The
+.Fn gid_from_group
+function returns the gid associated with the argument
+.Fa name .
+The gid is cached so that multiple calls with the same
+.Fa name
+do not require additional calls to
+.Xr getgrnam 3 .
+If there is no gid associated with the
+.Fa name ,
+the
+.Fn gid_from_group
+function returns -1; otherwise it stores the gid at the location pointed to by
+.Fa gid
+and returns 0.
.Sh SEE ALSO
.Xr getgrgid 3 ,
.Xr getpwuid 3
@@ -85,3 +123,12 @@ and
.Fn group_from_gid
functions first appeared in
.Bx 4.4 .
+.Pp
+The
+.Fn uid_from_user
+and
+.Fn gid_from_group
+functions were ported from
+.Nx
+and first appeared in
+.Ox 6.4 .
Index: lib/libc/gen/pwcache.c
===================================================================
RCS file: /cvs/src/lib/libc/gen/pwcache.c,v
retrieving revision 1.13
diff -u -p -u -r1.13 pwcache.c
--- lib/libc/gen/pwcache.c 25 Nov 2015 23:16:01 -0000 1.13
+++ lib/libc/gen/pwcache.c 12 Sep 2018 13:45:40 -0000
@@ -1,8 +1,13 @@
-/* $OpenBSD: pwcache.c,v 1.13 2015/11/25 23:16:01 jcs Exp $ */
-/*
- * Copyright (c) 1989, 1993
+/* $OpenBSD: pwcache.c,v 1.13 2015/11/25 23:16:01 jcs Exp $ */
+
+/*-
+ * Copyright (c) 1992 Keith Muller.
+ * Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
+ * This code is derived from software contributed to Berkeley by
+ * Keith Muller of the University of California, San Diego.
+ *
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
@@ -30,102 +35,403 @@
#include <sys/types.h>
+#include <assert.h>
#include <grp.h>
#include <pwd.h>
#include <stdio.h>
+#include <stdlib.h>
#include <string.h>
+#include <unistd.h>
+
+/*
+ * Constants and data structures used to implement group and password file
+ * caches. Name lengths have been chosen to be as large as those supported
+ * by the passwd and group files as well as the standard archive formats.
+ * CACHE SIZES MUST BE PRIME
+ */
+#define UNMLEN 32 /* >= user name found in any protocol */
+#define GNMLEN 32 /* >= group name found in any protocol */
+#define UID_SZ 317 /* size of uid to user_name cache */
+#define UNM_SZ 317 /* size of user_name to uid cache */
+#define GID_SZ 251 /* size of gid to group_name cache */
+#define GNM_SZ 251 /* size of group_name to gid cache */
+#define VALID 1 /* entry and name are valid */
+#define INVALID 2 /* entry valid, name NOT valid */
+
+/*
+ * Node structures used in the user, group, uid, and gid caches.
+ */
+
+typedef struct uidc {
+ int valid; /* is this a valid or a miss entry */
+ char name[UNMLEN]; /* uid name */
+ uid_t uid; /* cached uid */
+} UIDC;
+
+typedef struct gidc {
+ int valid; /* is this a valid or a miss entry */
+ char name[GNMLEN]; /* gid name */
+ gid_t gid; /* cached gid */
+} GIDC;
+
+/*
+ * Routines that control user, group, uid and gid caches.
+ * Traditional passwd/group cache routines perform quite poorly with
+ * archives. The chances of hitting a valid lookup with an archive is quite a
+ * bit worse than with files already resident on the file system. These misses
+ * create a MAJOR performance cost. To adress this problem, these routines
+ * cache both hits and misses.
+ */
+
+static UIDC **uidtb; /* uid to name cache */
+static GIDC **gidtb; /* gid to name cache */
+static UIDC **usrtb; /* user name to uid cache */
+static GIDC **grptb; /* group name to gid cache */
+
+static u_int
+st_hash(const char *name, size_t len, int tabsz)
+{
+ u_int key = 0;
+
+ assert(name != NULL);
+
+ while (len--) {
+ key += *name++;
+ key = (key << 8) | (key >> 24);
+ }
+
+ return key % tabsz;
+}
+
+/*
+ * uidtb_start
+ * creates an an empty uidtb
+ * Return:
+ * 0 if ok, -1 otherwise
+ */
+static int
+uidtb_start(void)
+{
+ static int fail = 0;
+
+ if (uidtb != NULL)
+ return 0;
+ if (fail)
+ return -1;
+ if ((uidtb = calloc(UID_SZ, sizeof(UIDC *))) == NULL) {
+ ++fail;
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * gidtb_start
+ * creates an an empty gidtb
+ * Return:
+ * 0 if ok, -1 otherwise
+ */
+static int
+gidtb_start(void)
+{
+ static int fail = 0;
+
+ if (gidtb != NULL)
+ return 0;
+ if (fail)
+ return -1;
+ if ((gidtb = calloc(GID_SZ, sizeof(GIDC *))) == NULL) {
+ ++fail;
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * usrtb_start
+ * creates an an empty usrtb
+ * Return:
+ * 0 if ok, -1 otherwise
+ */
+static int
+usrtb_start(void)
+{
+ static int fail = 0;
+
+ if (usrtb != NULL)
+ return 0;
+ if (fail)
+ return -1;
+ if ((usrtb = calloc(UNM_SZ, sizeof(UIDC *))) == NULL) {
+ ++fail;
+ return -1;
+ }
+ return 0;
+}
+
+/*
+ * grptb_start
+ * creates an an empty grptb
+ * Return:
+ * 0 if ok, -1 otherwise
+ */
+static int
+grptb_start(void)
+{
+ static int fail = 0;
+
+ if (grptb != NULL)
+ return 0;
+ if (fail)
+ return -1;
+ if ((grptb = calloc(GNM_SZ, sizeof(GIDC *))) == NULL) {
+ ++fail;
+ return -1;
+ }
+ return 0;
+}
-#define NCACHE 16 /* power of 2 */
-#define NLINES 4 /* associativity */
-#define MASK (NCACHE - 1) /* bits to store with */
-#define IDX(x, i) ((x & MASK) + i * NCACHE)
-
-char *
-user_from_uid(uid_t uid, int nouser)
-{
- static struct ncache {
- uid_t uid;
- short noname;
- char name[_PW_NAME_LEN + 1];
- } c_uid[NLINES * NCACHE];
+/*
+ * user_from_uid()
+ * caches the name (if any) for the uid. If noname clear, we always
+ * return the stored name (if valid or invalid match).
+ * We use a simple hash table.
+ * Return
+ * Pointer to stored name (or a empty string)
+ */
+const char *
+user_from_uid(uid_t uid, int noname)
+{
+ struct passwd pwstore, *pw = NULL;
char pwbuf[_PW_BUF_LEN];
- struct passwd pwstore, *pw;
- struct ncache *cp;
- unsigned int i;
-
- for (i = 0; i < NLINES; i++) {
- cp = &c_uid[IDX(uid, i)];
- if (!*cp->name) {
-fillit:
- cp->uid = uid;
- pw = NULL;
- getpwuid_r(uid, &pwstore, pwbuf, sizeof(pwbuf), &pw);
- if (pw == NULL) {
- snprintf(cp->name, sizeof(cp->name), "%u", uid);
- cp->noname = 1;
- } else {
- strlcpy(cp->name, pw->pw_name,
sizeof(cp->name));
- }
- }
- if (cp->uid == uid) {
- if (nouser && cp->noname)
- return NULL;
- return cp->name;
+ UIDC **pptr, *ptr = NULL;
+
+ if ((uidtb != NULL) || (uidtb_start() == 0)) {
+ /*
+ * see if we have this uid cached
+ */
+ pptr = uidtb + (uid % UID_SZ);
+ ptr = *pptr;
+
+ if ((ptr != NULL) && (ptr->valid > 0) && (ptr->uid == uid)) {
+ /*
+ * have an entry for this uid
+ */
+ if (!noname || (ptr->valid == VALID))
+ return ptr->name;
+ return NULL;
}
+
+ if (ptr == NULL)
+ *pptr = ptr = malloc(sizeof(UIDC));
+ }
+
+ getpwuid_r(uid, &pwstore, pwbuf, sizeof(pwbuf), &pw);
+ if (pw == NULL) {
+ /*
+ * no match for this uid in the local password file
+ * a string that is the uid in numeric format
+ */
+ if (ptr == NULL)
+ return NULL;
+ ptr->uid = uid;
+ (void)snprintf(ptr->name, UNMLEN, "%u", uid);
+ ptr->valid = INVALID;
+ if (noname)
+ return NULL;
+ } else {
+ /*
+ * there is an entry for this uid in the password file
+ */
+ if (ptr == NULL)
+ return pw->pw_name;
+ ptr->uid = uid;
+ (void)strlcpy(ptr->name, pw->pw_name, sizeof(ptr->name));
+ ptr->valid = VALID;
}
- /* move everybody down a slot */
- for (i = 0; i < NLINES - 1; i++) {
- struct ncache *next;
-
- cp = &c_uid[IDX(uid, i)];
- next = &c_uid[IDX(uid, i + 1)];
- memcpy(next, cp, sizeof(*cp));
- }
- cp = &c_uid[IDX(uid, 0)];
- goto fillit;
-}
-
-char *
-group_from_gid(gid_t gid, int nogroup)
-{
- static struct ncache {
- gid_t gid;
- short noname;
- char name[_PW_NAME_LEN + 1];
- } c_gid[NLINES * NCACHE];
+ return ptr->name;
+}
+
+/*
+ * group_from_gid()
+ * caches the name (if any) for the gid. If noname clear, we always
+ * return the stored name (if valid or invalid match).
+ * We use a simple hash table.
+ * Return
+ * Pointer to stored name (or a empty string)
+ */
+const char *
+group_from_gid(gid_t gid, int noname)
+{
+ struct group grstore, *gr = NULL;
char grbuf[_GR_BUF_LEN];
- struct group grstore, *gr;
- struct ncache *cp;
- unsigned int i;
-
- for (i = 0; i < NLINES; i++) {
- cp = &c_gid[IDX(gid, i)];
- if (!*cp->name) {
-fillit:
- cp->gid = gid;
- gr = NULL;
- getgrgid_r(gid, &grstore, grbuf, sizeof(grbuf), &gr);
- if (gr == NULL) {
- snprintf(cp->name, sizeof(cp->name), "%u", gid);
- cp->noname = 1;
- } else {
- strlcpy(cp->name, gr->gr_name,
sizeof(cp->name));
- }
+ GIDC **pptr, *ptr = NULL;
+
+ if ((gidtb != NULL) || (gidtb_start() == 0)) {
+ /*
+ * see if we have this gid cached
+ */
+ pptr = gidtb + (gid % GID_SZ);
+ ptr = *pptr;
+
+ if ((ptr != NULL) && (ptr->valid > 0) && (ptr->gid == gid)) {
+ /*
+ * have an entry for this gid
+ */
+ if (!noname || (ptr->valid == VALID))
+ return ptr->name;
+ return NULL;
}
- if (cp->gid == gid) {
- if (nogroup && cp->noname)
- return NULL;
- return cp->name;
+
+ if (ptr == NULL)
+ *pptr = ptr = malloc(sizeof(GIDC));
+ }
+
+ getgrgid_r(gid, &grstore, grbuf, sizeof(grbuf), &gr);
+ if (gr == NULL) {
+ /*
+ * no match for this gid in the local group file, put in
+ * a string that is the gid in numeric format
+ */
+ if (ptr == NULL)
+ return NULL;
+ ptr->gid = gid;
+ (void)snprintf(ptr->name, GNMLEN, "%u", gid);
+ ptr->valid = INVALID;
+ if (noname)
+ return NULL;
+ } else {
+ /*
+ * there is an entry for this group in the group file
+ */
+ if (ptr == NULL)
+ return gr->gr_name;
+ ptr->gid = gid;
+ (void)strlcpy(ptr->name, gr->gr_name, sizeof(ptr->name));
+ ptr->valid = VALID;
+ }
+ return ptr->name;
+}
+
+/*
+ * uid_from_user()
+ * caches the uid for a given user name. We use a simple hash table.
+ * Return
+ * the uid (if any) for a user name, or a -1 if no match can be found
+ */
+int
+uid_from_user(const char *name, uid_t *uid)
+{
+ struct passwd pwstore, *pw = NULL;
+ char pwbuf[_PW_BUF_LEN];
+ UIDC **pptr, *ptr = NULL;
+ size_t namelen;
+
+ /*
+ * return -1 for mangled names
+ */
+ if (name == NULL || ((namelen = strlen(name)) == 0))
+ return -1;
+
+ if ((usrtb != NULL) || (usrtb_start() == 0)) {
+ /*
+ * look up in hash table, if found and valid return the uid,
+ * if found and invalid, return a -1
+ */
+ pptr = usrtb + st_hash(name, namelen, UNM_SZ);
+ ptr = *pptr;
+
+ if ((ptr != NULL) && (ptr->valid > 0) &&
+ strcmp(name, ptr->name) == 0) {
+ if (ptr->valid == INVALID)
+ return -1;
+ *uid = ptr->uid;
+ return 0;
+ }
+
+ if (ptr == NULL)
+ *pptr = ptr = malloc(sizeof(UIDC));
+ }
+
+ /*
+ * no match, look it up, if no match store it as an invalid entry,
+ * or store the matching uid
+ */
+ getpwnam_r(name, &pwstore, pwbuf, sizeof(pwbuf), &pw);
+ if (ptr == NULL) {
+ if (pw == NULL)
+ return -1;
+ *uid = pw->pw_uid;
+ return 0;
+ }
+ (void)strlcpy(ptr->name, name, sizeof(ptr->name));
+ if (pw == NULL) {
+ ptr->valid = INVALID;
+ return -1;
+ }
+ ptr->valid = VALID;
+ *uid = ptr->uid = pw->pw_uid;
+ return 0;
+}
+
+/*
+ * gid_from_group()
+ * caches the gid for a given group name. We use a simple hash table.
+ * Return
+ * the gid (if any) for a group name, or a -1 if no match can be found
+ */
+int
+gid_from_group(const char *name, gid_t *gid)
+{
+ struct group grstore, *gr = NULL;
+ char grbuf[_GR_BUF_LEN];
+ GIDC **pptr, *ptr = NULL;
+ size_t namelen;
+
+ /*
+ * return -1 for mangled names
+ */
+ if (name == NULL || ((namelen = strlen(name)) == 0))
+ return -1;
+
+ if ((grptb != NULL) || (grptb_start() == 0)) {
+ /*
+ * look up in hash table, if found and valid return the uid,
+ * if found and invalid, return a -1
+ */
+ pptr = grptb + st_hash(name, namelen, GID_SZ);
+ ptr = *pptr;
+
+ if ((ptr != NULL) && (ptr->valid > 0) &&
+ strcmp(name, ptr->name) == 0) {
+ if (ptr->valid == INVALID)
+ return -1;
+ *gid = ptr->gid;
+ return 0;
}
+
+ if (ptr == NULL)
+ *pptr = ptr = malloc(sizeof(GIDC));
}
- /* move everybody down a slot */
- for (i = 0; i < NLINES - 1; i++) {
- struct ncache *next;
-
- cp = &c_gid[IDX(gid, i)];
- next = &c_gid[IDX(gid, i + 1)];
- memcpy(next, cp, sizeof(*cp));
+
+ /*
+ * no match, look it up, if no match store it as an invalid entry,
+ * or store the matching gid
+ */
+ getgrnam_r(name, &grstore, grbuf, sizeof(grbuf), &gr);
+ if (ptr == NULL) {
+ if (gr == NULL)
+ return -1;
+ *gid = gr->gr_gid;
+ return 0;
+ }
+
+ (void)strlcpy(ptr->name, name, sizeof(ptr->name));
+ if (gr == NULL) {
+ ptr->valid = INVALID;
+ return -1;
}
- cp = &c_gid[IDX(gid, 0)];
- goto fillit;
+ ptr->valid = VALID;
+ *gid = ptr->gid = gr->gr_gid;
+ return 0;
}
Index: lib/libc/gen/getgrent.c
===================================================================
RCS file: /cvs/src/lib/libc/gen/getgrent.c,v
retrieving revision 1.46
diff -u -p -u -r1.46 getgrent.c
--- lib/libc/gen/getgrent.c 1 Dec 2015 15:08:25 -0000 1.46
+++ lib/libc/gen/getgrent.c 10 Sep 2018 02:02:31 -0000
@@ -144,6 +144,7 @@ getgrnam_r(const char *name, struct grou
errno = errnosave;
return ret;
}
+DEF_WEAK(getgrnam_r);
static struct group *
getgrgid_gs(gid_t gid, struct group *p_gr, struct group_storage *gs)
Index: lib/libc/shlib_version
===================================================================
RCS file: /cvs/src/lib/libc/shlib_version,v
retrieving revision 1.199
diff -u -p -u -r1.199 shlib_version
--- lib/libc/shlib_version 13 Jul 2018 09:27:07 -0000 1.199
+++ lib/libc/shlib_version 10 Sep 2018 00:46:44 -0000
@@ -1,4 +1,4 @@
major=92
-minor=4
+minor=5
# note: If changes were made to include/thread_private.h or if system
# calls were added/changed then librthread/shlib_version also be updated.
Index: lib/libc/Symbols.list
===================================================================
RCS file: /cvs/src/lib/libc/Symbols.list,v
retrieving revision 1.63
diff -u -p -u -r1.63 Symbols.list
--- lib/libc/Symbols.list 13 Jul 2018 09:25:22 -0000 1.63
+++ lib/libc/Symbols.list 10 Sep 2018 00:46:44 -0000
@@ -663,6 +663,7 @@ getpwuid_shadow
getttyent
getttynam
getusershell
+gid_from_group
glob
globfree
group_from_gid
@@ -798,6 +799,7 @@ ttyname
ttyname_r
ttyslot
ualarm
+uid_from_user
uname
unvis
user_from_uid
Index: lib/libc/hidden/grp.h
===================================================================
RCS file: /cvs/src/lib/libc/hidden/grp.h,v
retrieving revision 1.2
diff -u -p -u -r1.2 grp.h
--- lib/libc/hidden/grp.h 24 Nov 2015 22:03:33 -0000 1.2
+++ lib/libc/hidden/grp.h 10 Sep 2018 00:46:44 -0000
@@ -29,7 +29,8 @@ PROTO_DEPRECATED(getgrent);
PROTO_DEPRECATED(getgrgid);
PROTO_NORMAL(getgrgid_r);
PROTO_DEPRECATED(getgrnam);
-PROTO_DEPRECATED(getgrnam_r);
+PROTO_NORMAL(getgrnam_r);
+PROTO_DEPRECATED(gid_from_group);
PROTO_DEPRECATED(group_from_gid);
PROTO_NORMAL(setgrent);
PROTO_NORMAL(setgroupent);
Index: lib/libc/hidden/pwd.h
===================================================================
RCS file: /cvs/src/lib/libc/hidden/pwd.h,v
retrieving revision 1.3
diff -u -p -u -r1.3 pwd.h
--- lib/libc/hidden/pwd.h 24 Nov 2015 22:03:33 -0000 1.3
+++ lib/libc/hidden/pwd.h 10 Sep 2018 00:46:44 -0000
@@ -40,6 +40,7 @@ PROTO_NORMAL(getpwuid_shadow);
PROTO_NORMAL(pw_dup);
PROTO_NORMAL(setpassent);
PROTO_DEPRECATED(setpwent);
+PROTO_DEPRECATED(uid_from_user);
PROTO_DEPRECATED(user_from_uid);
#endif /* !_LIBC_PWD_H_ */
