X-Git-Url: https://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fidcache.c;h=8b9db5ee506916a4f3601dd48fa0c39942f53776;hb=98171ec274fdcd518baf812ad0dd8933d2eee8ee;hp=a327067daf1adbfb8ead34d1af87a308da687273;hpb=0933dc6deb55554eeb9dbe540294c2019619541b;p=gnulib.git diff --git a/lib/idcache.c b/lib/idcache.c index a327067da..8b9db5ee5 100644 --- a/lib/idcache.c +++ b/lib/idcache.c @@ -1,10 +1,12 @@ /* idcache.c -- map user and group IDs, cached for speed - Copyright (C) 1985, 1988, 1989, 1990, 1997 Free Software Foundation, Inc. - This program is free software; you can redistribute it and/or modify + Copyright (C) 1985, 1988-1990, 1997-1998, 2003, 2005-2007, 2009-2013 Free + Software Foundation, Inc. + + This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of @@ -12,38 +14,25 @@ GNU General Public License for more details. You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software Foundation, - Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ + along with this program. If not, see . */ -#if HAVE_CONFIG_H -# include -#endif +#include +#include "idcache.h" +#include #include -#include +#include #include #include -#if defined(STDC_HEADERS) || defined(HAVE_STRING_H) -# include -#else -# include -#endif +#include -#if HAVE_UNISTD_H -# include -#endif +#include "xalloc.h" -#ifndef _POSIX_VERSION -struct passwd *getpwuid (); -struct passwd *getpwnam (); -struct group *getgrgid (); -struct group *getgrnam (); +#ifdef __DJGPP__ +static char digits[] = "0123456789"; #endif -char *xmalloc (); -char *xstrdup (); - struct userid { union @@ -51,55 +40,70 @@ struct userid uid_t u; gid_t g; } id; - char *name; struct userid *next; + char name[FLEXIBLE_ARRAY_MEMBER]; }; +/* FIXME: provide a function to free any malloc'd storage and reset lists, + so that an application can use code like this just before exiting: + #ifdef lint + idcache_clear (); + #endif +*/ + static struct userid *user_alist; -#ifdef NOT_USED -/* The members of this list have names not in the local passwd file. */ +/* Each entry on list is a user name for which the first lookup failed. */ static struct userid *nouser_alist; -#endif /* NOT_USED */ -/* Translate UID to a login name, with cache. - If UID cannot be resolved, return NULL. - Cache lookup failures, too. */ +/* Use the same struct as for userids. */ +static struct userid *group_alist; + +/* Each entry on list is a group name for which the first lookup failed. */ +static struct userid *nogroup_alist; + +/* Translate UID to a login name, with cache, or NULL if unresolved. */ char * -getuser (uid) - uid_t uid; +getuser (uid_t uid) { - register struct userid *tail; - struct passwd *pwent; + struct userid *tail; + struct userid *match = NULL; for (tail = user_alist; tail; tail = tail->next) - if (tail->id.u == uid) - return tail->name; + { + if (tail->id.u == uid) + { + match = tail; + break; + } + } - pwent = getpwuid (uid); - tail = (struct userid *) xmalloc (sizeof (struct userid)); - tail->id.u = uid; - tail->name = (pwent ? xstrdup (pwent->pw_name) : NULL); + if (match == NULL) + { + struct passwd *pwent = getpwuid (uid); + char const *name = pwent ? pwent->pw_name : ""; + match = xmalloc (offsetof (struct userid, name) + strlen (name) + 1); + match->id.u = uid; + strcpy (match->name, name); + + /* Add to the head of the list, so most recently used is first. */ + match->next = user_alist; + user_alist = match; + } - /* Add to the head of the list, so most recently used is first. */ - tail->next = user_alist; - user_alist = tail; - return tail->name; + return match->name[0] ? match->name : NULL; } -#ifdef NOT_USED - /* Translate USER to a UID, with cache. Return NULL if there is no such user. (We also cache which user names have no passwd entry, so we don't keep looking them up.) */ uid_t * -getuidbyname (user) - const char *user; +getuidbyname (const char *user) { - register struct userid *tail; + struct userid *tail; struct passwd *pwent; for (tail = user_alist; tail; tail = tail->next) @@ -110,12 +114,21 @@ getuidbyname (user) for (tail = nouser_alist; tail; tail = tail->next) /* Avoid a function call for the most common case. */ if (*tail->name == *user && !strcmp (tail->name, user)) - return 0; + return NULL; pwent = getpwnam (user); +#ifdef __DJGPP__ + /* We need to pretend to be the user USER, to make + pwd functions know about an arbitrary user name. */ + if (!pwent && strspn (user, digits) < strlen (user)) + { + setenv ("USER", user, 1); + pwent = getpwnam (user); /* now it will succeed */ + } +#endif - tail = (struct userid *) xmalloc (sizeof (struct userid)); - tail->name = xstrdup (user); + tail = xmalloc (offsetof (struct userid, name) + strlen (user) + 1); + strcpy (tail->name, user); /* Add to the head of the list, so most recently used is first. */ if (pwent) @@ -128,52 +141,51 @@ getuidbyname (user) tail->next = nouser_alist; nouser_alist = tail; - return 0; + return NULL; } -#endif /* NOT_USED */ - -/* Use the same struct as for userids. */ -static struct userid *group_alist; -static struct userid *nogroup_alist; - -/* Translate GID to a group name or a stringified number, - with cache. */ +/* Translate GID to a group name, with cache, or NULL if unresolved. */ char * -getgroup (gid) - gid_t gid; +getgroup (gid_t gid) { - register struct userid *tail; - struct group *grent; + struct userid *tail; + struct userid *match = NULL; for (tail = group_alist; tail; tail = tail->next) - if (tail->id.g == gid) - return tail->name; + { + if (tail->id.g == gid) + { + match = tail; + break; + } + } - grent = getgrgid (gid); - tail = (struct userid *) xmalloc (sizeof (struct userid)); - tail->id.g = gid; - tail->name = (grent ? xstrdup (grent->gr_name) : NULL); + if (match == NULL) + { + struct group *grent = getgrgid (gid); + char const *name = grent ? grent->gr_name : ""; + match = xmalloc (offsetof (struct userid, name) + strlen (name) + 1); + match->id.g = gid; + strcpy (match->name, name); + + /* Add to the head of the list, so most recently used is first. */ + match->next = group_alist; + group_alist = match; + } - /* Add to the head of the list, so most recently used is first. */ - tail->next = group_alist; - group_alist = tail; - return tail->name; + return match->name[0] ? match->name : NULL; } -#ifdef NOT_USED - /* Translate GROUP to a GID, with cache. Return NULL if there is no such group. (We also cache which group names have no group entry, so we don't keep looking them up.) */ gid_t * -getgidbyname (group) - const char *group; +getgidbyname (const char *group) { - register struct userid *tail; + struct userid *tail; struct group *grent; for (tail = group_alist; tail; tail = tail->next) @@ -184,12 +196,21 @@ getgidbyname (group) for (tail = nogroup_alist; tail; tail = tail->next) /* Avoid a function call for the most common case. */ if (*tail->name == *group && !strcmp (tail->name, group)) - return 0; + return NULL; grent = getgrnam (group); +#ifdef __DJGPP__ + /* We need to pretend to belong to group GROUP, to make + grp functions know about an arbitrary group name. */ + if (!grent && strspn (group, digits) < strlen (group)) + { + setenv ("GROUP", group, 1); + grent = getgrnam (group); /* now it will succeed */ + } +#endif - tail = (struct userid *) xmalloc (sizeof (struct userid)); - tail->name = xstrdup (group); + tail = xmalloc (offsetof (struct userid, name) + strlen (group) + 1); + strcpy (tail->name, group); /* Add to the head of the list, so most recently used is first. */ if (grent) @@ -202,7 +223,5 @@ getgidbyname (group) tail->next = nogroup_alist; nogroup_alist = tail; - return 0; + return NULL; } - -#endif /* NOT_USED */