vi: fixes to string search in colon commands, closes 10321
[oweals/busybox.git] / libpwdgrp / pwd_grp.c
index 98b8367ca28945e04a68e2cf5a2f1a6963a34db4..b44ada4323ecd041e36cf7590f24f99679790e9a 100644 (file)
 /* vi: set sw=4 ts=4: */
-/*  Copyright (C) 2003     Manuel Novoa III
+/*
+ * Copyright (C) 2014 Tito Ragusa <farmatito@tiscali.it>
  *
- *  Licensed under GPL v2, or later.  See file LICENSE in this tarball.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
-
-/*  Nov 6, 2003  Initial version.
- *
- *  NOTE: This implementation is quite strict about requiring all
- *    field seperators.  It also does not allow leading whitespace
- *    except when processing the numeric fields.  glibc is more
- *    lenient.  See the various glibc difference comments below.
+/* This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY!!
  *
- *  TODO:
- *    Move to dynamic allocation of (currently statically allocated)
- *      buffers; especially for the group-related functions since
- *      large group member lists will cause error returns.
+ * Rewrite of some parts. Main differences are:
  *
+ * 1) the buffer for getpwuid, getgrgid, getpwnam, getgrnam is dynamically
+ *    allocated.
+ *    If ENABLE_FEATURE_CLEAN_UP is set the buffers are freed at program
+ *    exit using the atexit function to make valgrind happy.
+ * 2) the passwd/group files:
+ *      a) must contain the expected number of fields (as per count of field
+ *         delimiters ":") or we will complain with a error message.
+ *      b) leading and trailing whitespace in fields is stripped.
+ *      c) some fields are not allowed to be empty (e.g. username, uid/gid),
+ *         and in this case NULL is returned and errno is set to EINVAL.
+ *         This behaviour could be easily changed by modifying PW_DEF, GR_DEF,
+ *         SP_DEF strings (uppercase makes a field mandatory).
+ *      d) the string representing uid/gid must be convertible by strtoXX
+ *         functions, or errno is set to EINVAL.
+ *      e) leading and trailing whitespace in group member names is stripped.
+ * 3) the internal function for getgrouplist uses dynamically allocated buffer.
+ * 4) at the moment only the functions really used by busybox code are
+ *    implemented, if you need a particular missing function it should be
+ *    easy to write it by using the internal common code.
  */
-
 #include "libbb.h"
-#include <features.h>
-#include <assert.h>
-
-#ifndef _PATH_SHADOW
-#define        _PATH_SHADOW    "/etc/shadow"
-#endif
-#ifndef _PATH_PASSWD
-#define        _PATH_PASSWD    "/etc/passwd"
-#endif
-#ifndef _PATH_GROUP
-#define        _PATH_GROUP     "/etc/group"
-#endif
-
-/**********************************************************************/
-/* Sizes for statically allocated buffers. */
-
-/* If you change these values, also change _SC_GETPW_R_SIZE_MAX and
- * _SC_GETGR_R_SIZE_MAX in libc/unistd/sysconf.c to match */
-#define PWD_BUFFER_SIZE 256
-#define GRP_BUFFER_SIZE 256
-
-/**********************************************************************/
-/* Prototypes for internal functions. */
 
-static int bb__pgsreader(int (*parserfunc)(void *d, char *line), void *data,
-               char *__restrict line_buff, size_t buflen, FILE *f);
+struct const_passdb {
+       const char *filename;
+       char def[7 + 2*ENABLE_USE_BB_SHADOW];
+       uint8_t off[7 + 2*ENABLE_USE_BB_SHADOW];
+       uint8_t numfields;
+       uint8_t size_of;
+};
+struct passdb {
+       const char *filename;
+       char def[7 + 2*ENABLE_USE_BB_SHADOW];
+       uint8_t off[7 + 2*ENABLE_USE_BB_SHADOW];
+       uint8_t numfields;
+       uint8_t size_of;
+       FILE *fp;
+       char *malloced;
+};
+/* Note: for shadow db, def[] will not contain terminating NUL,
+ * but convert_to_struct() logic detects def[] end by "less than SP?",
+ * not by "is it NUL?" condition; and off[0] happens to be zero
+ * for every db anyway, so there _is_ in fact a terminating NUL there.
+ */
 
-static int bb__parsepwent(void *pw, char *line);
-static int bb__parsegrent(void *gr, char *line);
+/* S = string not empty, s = string maybe empty,
+ * I = uid,gid, l = long maybe empty, m = members,
+ * r = reserved
+ */
+#define PW_DEF "SsIIsss"
+#define GR_DEF "SsIm"
+#define SP_DEF "Ssllllllr"
+
+static const struct const_passdb const_pw_db = {
+       _PATH_PASSWD, PW_DEF,
+       {
+               offsetof(struct passwd, pw_name),       /* 0 S */
+               offsetof(struct passwd, pw_passwd),     /* 1 s */
+               offsetof(struct passwd, pw_uid),        /* 2 I */
+               offsetof(struct passwd, pw_gid),        /* 3 I */
+               offsetof(struct passwd, pw_gecos),      /* 4 s */
+               offsetof(struct passwd, pw_dir),        /* 5 s */
+               offsetof(struct passwd, pw_shell)       /* 6 s */
+       },
+       sizeof(PW_DEF)-1, sizeof(struct passwd)
+};
+static const struct const_passdb const_gr_db = {
+       _PATH_GROUP, GR_DEF,
+       {
+               offsetof(struct group, gr_name),        /* 0 S */
+               offsetof(struct group, gr_passwd),      /* 1 s */
+               offsetof(struct group, gr_gid),         /* 2 I */
+               offsetof(struct group, gr_mem)          /* 3 m (char **) */
+       },
+       sizeof(GR_DEF)-1, sizeof(struct group)
+};
 #if ENABLE_USE_BB_SHADOW
-static int bb__parsespent(void *sp, char *line);
+static const struct const_passdb const_sp_db = {
+       _PATH_SHADOW, SP_DEF,
+       {
+               offsetof(struct spwd, sp_namp),         /* 0 S Login name */
+               offsetof(struct spwd, sp_pwdp),         /* 1 s Encrypted password */
+               offsetof(struct spwd, sp_lstchg),       /* 2 l */
+               offsetof(struct spwd, sp_min),          /* 3 l */
+               offsetof(struct spwd, sp_max),          /* 4 l */
+               offsetof(struct spwd, sp_warn),         /* 5 l */
+               offsetof(struct spwd, sp_inact),        /* 6 l */
+               offsetof(struct spwd, sp_expire),       /* 7 l */
+               offsetof(struct spwd, sp_flag)          /* 8 r Reserved */
+       },
+       sizeof(SP_DEF)-1, sizeof(struct spwd)
+};
 #endif
 
-/**********************************************************************/
 /* We avoid having big global data. */
-
 struct statics {
-       /* Smaller things first */
-       struct passwd getpwuid_resultbuf;
-       struct group getgrgid_resultbuf;
-       struct passwd getpwnam_resultbuf;
-       struct group getgrnam_resultbuf;
-
-       char getpwuid_buffer[PWD_BUFFER_SIZE];
-       char getgrgid_buffer[GRP_BUFFER_SIZE];
-       char getpwnam_buffer[PWD_BUFFER_SIZE];
-       char getgrnam_buffer[GRP_BUFFER_SIZE];
-#if 0
-       struct passwd fgetpwent_resultbuf;
-       struct group fgetgrent_resultbuf;
-       struct spwd fgetspent_resultbuf;
-       char fgetpwent_buffer[PWD_BUFFER_SIZE];
-       char fgetgrent_buffer[GRP_BUFFER_SIZE];
-       char fgetspent_buffer[PWD_BUFFER_SIZE];
-#endif
-#if 0 //ENABLE_USE_BB_SHADOW
-       struct spwd getspuid_resultbuf;
-       struct spwd getspnam_resultbuf;
-       char getspuid_buffer[PWD_BUFFER_SIZE];
-       char getspnam_buffer[PWD_BUFFER_SIZE];
-#endif
-// Not converted - too small to bother
-//pthread_mutex_t mylock = PTHREAD_MUTEX_INITIALIZER;
-//FILE *pwf /*= NULL*/;
-//FILE *grf /*= NULL*/;
-//FILE *spf /*= NULL*/;
-#if 0
-       struct passwd getpwent_pwd;
-       struct group getgrent_gr;
-       char getpwent_line_buff[PWD_BUFFER_SIZE];
-       char getgrent_line_buff[GRP_BUFFER_SIZE];
-#endif
-#if 0 //ENABLE_USE_BB_SHADOW
-       struct spwd getspent_spwd;
-       struct spwd sgetspent_spwd;
-       char getspent_line_buff[PWD_BUFFER_SIZE];
-       char sgetspent_line_buff[PWD_BUFFER_SIZE];
-#endif
+       /* We use same buffer (db[0].malloced) for getpwuid and getpwnam.
+        * Manpage says:
+        * "The return value may point to a static area, and may be overwritten
+        * by subsequent calls to getpwent(), getpwnam(), or getpwuid()."
+        */
+       struct passdb db[2 + ENABLE_USE_BB_SHADOW];
+       char *tokenize_end;
+       unsigned string_size;
 };
 
 static struct statics *ptr_to_statics;
+#define S     (*ptr_to_statics)
+#define has_S (ptr_to_statics)
+
+#if ENABLE_FEATURE_CLEAN_UP
+static void free_static(void)
+{
+       free(S.db[0].malloced);
+       free(S.db[1].malloced);
+# if ENABLE_USE_BB_SHADOW
+       free(S.db[2].malloced);
+# endif
+       free(ptr_to_statics);
+}
+#endif
 
 static struct statics *get_S(void)
 {
-       if (!ptr_to_statics)
-               ptr_to_statics = xzalloc(sizeof(*ptr_to_statics));
+       if (!ptr_to_statics) {
+               ptr_to_statics = xzalloc(sizeof(S));
+               memcpy(&S.db[0], &const_pw_db, sizeof(const_pw_db));
+               memcpy(&S.db[1], &const_gr_db, sizeof(const_gr_db));
+#if ENABLE_USE_BB_SHADOW
+               memcpy(&S.db[2], &const_sp_db, sizeof(const_sp_db));
+#endif
+#if ENABLE_FEATURE_CLEAN_UP
+               atexit(free_static);
+#endif
+       }
        return ptr_to_statics;
 }
 
-/* Always use in this order, get_S() must be called first */
-#define RESULTBUF(name) &((S = get_S())->name##_resultbuf)
-#define BUFFER(name)    (S->name##_buffer)
+/* Internal functions */
 
-/**********************************************************************/
-/* For the various fget??ent_r funcs, return
- *
- *  0: success
- *  ENOENT: end-of-file encountered
- *  ERANGE: buflen too small
- *  other error values possible. See bb__pgsreader.
- *
- * Also, *result == resultbuf on success and NULL on failure.
- *
- * NOTE: glibc difference - For the ENOENT case, glibc also sets errno.
- *   We do not, as it really isn't an error if we reach the end-of-file.
- *   Doing so is analogous to having fgetc() set errno on EOF.
+/* Divide the passwd/group/shadow record in fields
+ * by substituting the given delimiter
+ * e.g. ':' or ',' with '\0'.
+ * Returns the number of fields found.
+ * Strips leading and trailing whitespace in fields.
  */
-/**********************************************************************/
-
-int fgetpwent_r(FILE *__restrict stream, struct passwd *__restrict resultbuf,
-                               char *__restrict buffer, size_t buflen,
-                               struct passwd **__restrict result)
+static int tokenize(char *buffer, int ch)
 {
-       int rv;
-
-       *result = NULL;
+       char *p = buffer;
+       char *s = p;
+       int num_fields = 0;
 
-       rv = bb__pgsreader(bb__parsepwent, resultbuf, buffer, buflen, stream);
-       if (!rv) {
-               *result = resultbuf;
+       for (;;) {
+               if (isblank(*s)) {
+                       overlapping_strcpy(s, skip_whitespace(s));
+               }
+               if (*p == ch || *p == '\0') {
+                       char *end = p;
+                       while (p != s && isblank(p[-1]))
+                               p--;
+                       if (p != end)
+                               overlapping_strcpy(p, end);
+                       num_fields++;
+                       if (*end == '\0') {
+                               S.tokenize_end = p + 1;
+                               return num_fields;
+                       }
+                       *p = '\0';
+                       s = p + 1;
+               }
+               p++;
        }
-
-       return rv;
 }
 
-int fgetgrent_r(FILE *__restrict stream, struct group *__restrict resultbuf,
-                               char *__restrict buffer, size_t buflen,
-                               struct group **__restrict result)
-{
-       int rv;
+/* Returns !NULL on success and matching line broken up in fields by '\0' in buf.
+ * We require the expected number of fields to be found.
+ */
+static char *parse_common(FILE *fp, struct passdb *db,
+               const char *key, int field_pos)
+{
+       char *buf;
+
+       while ((buf = xmalloc_fgetline(fp)) != NULL) {
+               /* Skip empty lines, comment lines */
+               if (buf[0] == '\0' || buf[0] == '#')
+                       goto free_and_next;
+               if (tokenize(buf, ':') != db->numfields) {
+                       /* number of fields is wrong */
+                       bb_error_msg("%s: bad record", db->filename);
+                       goto free_and_next;
+               }
 
-       *result = NULL;
+               if (field_pos == -1) {
+                       /* no key specified: sequential read, return a record */
+                       break;
+               }
+               if (strcmp(key, nth_string(buf, field_pos)) == 0) {
+                       /* record found */
+                       break;
+               }
+ free_and_next:
+               free(buf);
+       }
 
-       rv = bb__pgsreader(bb__parsegrent, resultbuf, buffer, buflen, stream);
-       if (!rv) {
-               *result = resultbuf;
+       S.string_size = S.tokenize_end - buf;
+/*
+ * Ugly hack: group db requires additional buffer space
+ * for members[] array. If there is only one group, we need space
+ * for 3 pointers: alignment padding, group name, NULL.
+ * +1 for every additional group.
+ */
+       if (buf && db->numfields == sizeof(GR_DEF)-1) { /* if we read group file... */
+               int cnt = 3;
+               char *p = buf;
+               while (p < S.tokenize_end)
+                       if (*p++ == ',')
+                               cnt++;
+               S.string_size += cnt * sizeof(char*);
+//bb_error_msg("+%d words = %u key:%s buf:'%s'", cnt, S.string_size, key, buf);
+               buf = xrealloc(buf, S.string_size);
        }
 
-       return rv;
+       return buf;
 }
 
-#if ENABLE_USE_BB_SHADOW
-int fgetspent_r(FILE *__restrict stream, struct spwd *__restrict resultbuf,
-                               char *__restrict buffer, size_t buflen,
-                               struct spwd **__restrict result)
+static char *parse_file(struct passdb *db,
+               const char *key, int field_pos)
 {
-       int rv;
+       char *buf = NULL;
+       FILE *fp = fopen_for_read(db->filename);
 
-       *result = NULL;
-
-       rv = bb__pgsreader(bb__parsespent, resultbuf, buffer, buflen, stream);
-       if (!rv) {
-               *result = resultbuf;
+       if (fp) {
+               buf = parse_common(fp, db, key, field_pos);
+               fclose(fp);
        }
-
-       return rv;
+       return buf;
 }
-#endif
-
-/**********************************************************************/
-/* For the various fget??ent funcs, return NULL on failure and a
- * pointer to the appropriate struct (statically allocated) on success.
- * TODO: audit & stop using these in bbox, they pull in static buffers */
-/**********************************************************************/
 
-#if 0
-struct passwd *fgetpwent(FILE *stream)
+/* Convert passwd/group/shadow file record in buffer to a struct */
+static void *convert_to_struct(struct passdb *db,
+               char *buffer, void *result)
 {
-       struct statics *S;
-       struct passwd *resultbuf = RESULTBUF(fgetpwent);
-       char *buffer = BUFFER(fgetpwent);
-       struct passwd *result;
-
-       fgetpwent_r(stream, resultbuf, buffer, sizeof(BUFFER(fgetpwent)), &result);
-       return result;
-}
+       const char *def = db->def;
+       const uint8_t *off = db->off;
 
-struct group *fgetgrent(FILE *stream)
-{
-       struct statics *S;
-       struct group *resultbuf = RESULTBUF(fgetgrent);
-       char *buffer = BUFFER(fgetgrent);
-       struct group *result;
+       /* For consistency, zero out all fields */
+       memset(result, 0, db->size_of);
 
-       fgetgrent_r(stream, resultbuf, buffer, sizeof(BUFFER(fgetgrent)), &result);
-       return result;
-}
-#endif
+       for (;;) {
+               void *member = (char*)result + (*off++);
 
+               if ((*def | 0x20) == 's') { /* s or S */
+                       *(char **)member = (char*)buffer;
+                       if (!buffer[0] && (*def == 'S')) {
+                               errno = EINVAL;
+                       }
+               }
+               if (*def == 'I') {
+                       *(int *)member = bb_strtou(buffer, NULL, 10);
+               }
 #if ENABLE_USE_BB_SHADOW
-#if 0
-struct spwd *fgetspent(FILE *stream)
-{
-       struct statics *S;
-       struct spwd *resultbuf = RESULTBUF(fgetspent);
-       char *buffer = BUFFER(fgetspent);
-       struct spwd *result;
-
-       fgetspent_r(stream, resultbuf, buffer, sizeof(BUFFER(fgetspent)), &result);
-       return result;
-}
+               if (*def == 'l') {
+                       long n = -1;
+                       if (buffer[0])
+                               n = bb_strtol(buffer, NULL, 10);
+                       *(long *)member = n;
+               }
 #endif
-
-int sgetspent_r(const char *string, struct spwd *result_buf,
-                               char *buffer, size_t buflen, struct spwd **result)
-{
-       int rv = ERANGE;
-
-       *result = NULL;
-
-       if (buflen < PWD_BUFFER_SIZE) {
-       DO_ERANGE:
-               errno=rv;
-               goto DONE;
-       }
-
-       if (string != buffer) {
-               if (strlen(string) >= buflen) {
-                       goto DO_ERANGE;
+               if (*def == 'm') {
+                       char **members;
+                       int i = tokenize(buffer, ',');
+
+                       /* Store members[] after buffer's end.
+                        * This is safe ONLY because there is a hack
+                        * in parse_common() which allocates additional space
+                        * at the end of malloced buffer!
+                        */
+                       members = (char **)
+                               ( ((intptr_t)S.tokenize_end + sizeof(members[0]))
+                               & -(intptr_t)sizeof(members[0])
+                               );
+                       ((struct group *)result)->gr_mem = members;
+                       while (--i >= 0) {
+                               if (buffer[0]) {
+                                       *members++ = buffer;
+                                       // bb_error_msg("member[]='%s'", buffer);
+                               }
+                               buffer += strlen(buffer) + 1;
+                       }
+                       *members = NULL;
                }
-               strcpy(buffer, string);
-       }
+               /* def "r" does nothing */
 
-       rv = bb__parsespent(result_buf, buffer);
-       if (!rv) {
-               *result = result_buf;
+               def++;
+               if ((unsigned char)*def <= (unsigned char)' ')
+                       break;
+               buffer += strlen(buffer) + 1;
        }
 
- DONE:
-       return rv;
-}
-#endif
-
-/**********************************************************************/
-
-#define GETXXKEY_R_FUNC         getpwnam_r
-#define GETXXKEY_R_PARSER       bb__parsepwent
-#define GETXXKEY_R_ENTTYPE      struct passwd
-#define GETXXKEY_R_TEST(ENT)    (!strcmp((ENT)->pw_name, key))
-#define GETXXKEY_R_KEYTYPE      const char *__restrict
-#define GETXXKEY_R_PATHNAME     _PATH_PASSWD
-#include "pwd_grp_internal.c"
-
-#define GETXXKEY_R_FUNC         getgrnam_r
-#define GETXXKEY_R_PARSER       bb__parsegrent
-#define GETXXKEY_R_ENTTYPE      struct group
-#define GETXXKEY_R_TEST(ENT)    (!strcmp((ENT)->gr_name, key))
-#define GETXXKEY_R_KEYTYPE      const char *__restrict
-#define GETXXKEY_R_PATHNAME     _PATH_GROUP
-#include "pwd_grp_internal.c"
-
-#if ENABLE_USE_BB_SHADOW
-#define GETXXKEY_R_FUNC         getspnam_r
-#define GETXXKEY_R_PARSER       bb__parsespent
-#define GETXXKEY_R_ENTTYPE      struct spwd
-#define GETXXKEY_R_TEST(ENT)    (!strcmp((ENT)->sp_namp, key))
-#define GETXXKEY_R_KEYTYPE      const char *__restrict
-#define GETXXKEY_R_PATHNAME     _PATH_SHADOW
-#include "pwd_grp_internal.c"
-#endif
-
-#define GETXXKEY_R_FUNC         getpwuid_r
-#define GETXXKEY_R_PARSER       bb__parsepwent
-#define GETXXKEY_R_ENTTYPE      struct passwd
-#define GETXXKEY_R_TEST(ENT)    ((ENT)->pw_uid == key)
-#define GETXXKEY_R_KEYTYPE      uid_t
-#define GETXXKEY_R_PATHNAME     _PATH_PASSWD
-#include "pwd_grp_internal.c"
-
-#define GETXXKEY_R_FUNC         getgrgid_r
-#define GETXXKEY_R_PARSER       bb__parsegrent
-#define GETXXKEY_R_ENTTYPE      struct group
-#define GETXXKEY_R_TEST(ENT)    ((ENT)->gr_gid == key)
-#define GETXXKEY_R_KEYTYPE      gid_t
-#define GETXXKEY_R_PATHNAME     _PATH_GROUP
-#include "pwd_grp_internal.c"
-
-/**********************************************************************/
-/* TODO: audit & stop using these in bbox, they pull in static buffers */
-
-/* This one has many users */
-struct passwd *getpwuid(uid_t uid)
-{
-       struct statics *S;
-       struct passwd *resultbuf = RESULTBUF(getpwuid);
-       char *buffer = BUFFER(getpwuid);
-       struct passwd *result;
-
-       getpwuid_r(uid, resultbuf, buffer, sizeof(BUFFER(getpwuid)), &result);
+       if (errno)
+               result = NULL;
        return result;
 }
 
-/* This one has many users */
-struct group *getgrgid(gid_t gid)
+static int massage_data_for_r_func(struct passdb *db,
+               char *buffer, size_t buflen,
+               void **result,
+               char *buf)
 {
-       struct statics *S;
-       struct group *resultbuf = RESULTBUF(getgrgid);
-       char *buffer = BUFFER(getgrgid);
-       struct group *result;
-
-       getgrgid_r(gid, resultbuf, buffer, sizeof(BUFFER(getgrgid)), &result);
-       return result;
-}
-
-#if 0 //ENABLE_USE_BB_SHADOW
-/* This function is non-standard and is currently not built.  It seems
- * to have been created as a reentrant version of the non-standard
- * functions getspuid.  Why getspuid was added, I do not know. */
-int getspuid_r(uid_t uid, struct spwd *__restrict resultbuf,
-                      char *__restrict buffer, size_t buflen,
-                      struct spwd **__restrict result)
-{
-       int rv;
-       struct passwd *pp;
-       struct passwd password;
-       char pwd_buff[PWD_BUFFER_SIZE];
-
+       void *result_buf = *result;
        *result = NULL;
-       rv = getpwuid_r(uid, &password, pwd_buff, sizeof(pwd_buff), &pp);
-       if (!rv) {
-               rv = getspnam_r(password.pw_name, resultbuf, buffer, buflen, result);
+       if (buf) {
+               if (S.string_size > buflen) {
+                       errno = ERANGE;
+               } else {
+                       memcpy(buffer, buf, S.string_size);
+                       *result = convert_to_struct(db, buffer, result_buf);
+               }
+               free(buf);
        }
-
-       return rv;
+       /* "The reentrant functions return zero on success.
+        * In case of error, an error number is returned."
+        * NB: not finding the record is also a "success" here:
+        */
+       return errno;
 }
 
-/* This function is non-standard and is currently not built.
- * Why it was added, I do not know. */
-struct spwd *getspuid(uid_t uid)
+static void* massage_data_for_non_r_func(struct passdb *db, char *buf)
 {
-       struct statics *S;
-       struct spwd *resultbuf = RESULTBUF(getspuid);
-       char *buffer = BUFFER(getspuid);
-       struct spwd *result;
+       if (!buf)
+               return NULL;
 
-       getspuid_r(uid, resultbuf, buffer, sizeof(BUFFER(getspuid)), &result);
-       return result;
+       free(db->malloced);
+       /* We enlarge buf and move string data up, freeing space
+        * for struct passwd/group/spwd at the beginning. This way,
+        * entire result of getXXnam is in a single malloced block.
+        * This enables easy creation of xmalloc_getpwnam() API.
+        */
+       db->malloced = buf = xrealloc(buf, db->size_of + S.string_size);
+       memmove(buf + db->size_of, buf, S.string_size);
+       return convert_to_struct(db, buf + db->size_of, buf);
 }
-#endif
 
-/* This one has many users */
-struct passwd *getpwnam(const char *name)
+/****** getXXnam/id_r */
+
+static int FAST_FUNC getXXnam_r(const char *name, uintptr_t db_and_field_pos,
+               char *buffer, size_t buflen,
+               void *result)
 {
-       struct statics *S;
-       struct passwd *resultbuf = RESULTBUF(getpwnam);
-       char *buffer = BUFFER(getpwnam);
-       struct passwd *result;
+       char *buf;
+       struct passdb *db = &get_S()->db[db_and_field_pos >> 2];
 
-       getpwnam_r(name, resultbuf, buffer, sizeof(BUFFER(getpwnam)), &result);
-       return result;
+       buf = parse_file(db, name, 0 /*db_and_field_pos & 3*/);
+       /* "db_and_field_pos & 3" is commented out since so far we don't implement
+        * getXXXid_r() functions which would use that to pass 2 here */
+
+       return massage_data_for_r_func(db, buffer, buflen, result, buf);
 }
 
-/* This one has many users */
-struct group *getgrnam(const char *name)
+int FAST_FUNC getpwnam_r(const char *name, struct passwd *struct_buf,
+               char *buffer, size_t buflen,
+               struct passwd **result)
 {
-       struct statics *S;
-       struct group *resultbuf = RESULTBUF(getgrnam);
-       char *buffer = BUFFER(getgrnam);
-       struct group *result;
-
-       getgrnam_r(name, resultbuf, buffer, sizeof(BUFFER(getgrnam)), &result);
-       return result;
+       /* Why the "store buffer address in result" trick?
+        * This way, getXXnam_r has the same ABI signature as getpwnam_r,
+        * hopefully compiler can optimize tail call better in this case.
+        */
+       *result = struct_buf;
+       return getXXnam_r(name, (0 << 2) + 0, buffer, buflen, result);
 }
-
-#if 0 //ENABLE_USE_BB_SHADOW
-struct spwd *getspnam(const char *name)
+#if ENABLE_USE_BB_SHADOW
+int FAST_FUNC getspnam_r(const char *name, struct spwd *struct_buf, char *buffer, size_t buflen,
+               struct spwd **result)
 {
-       struct statics *S;
-       struct spwd *resultbuf = RESULTBUF(getspnam);
-       char *buffer = BUFFER(getspnam);
-       struct spwd *result;
-
-       getspnam_r(name, resultbuf, buffer, sizeof(BUFFER(getspnam)), &result);
-       return result;
+       *result = struct_buf;
+       return getXXnam_r(name, (2 << 2) + 0, buffer, buflen, result);
 }
 #endif
 
-/* This one doesn't use static buffers */
-int getpw(uid_t uid, char *buf)
+#ifdef UNUSED
+/****** getXXent_r */
+
+static int FAST_FUNC getXXent_r(uintptr_t db_idx, char *buffer, size_t buflen,
+               void *result)
 {
-       struct passwd resultbuf;
-       struct passwd *result;
-       char buffer[PWD_BUFFER_SIZE];
+       char *buf;
+       struct passdb *db = &get_S()->db[db_idx];
 
-       if (!buf) {
-               errno = EINVAL;
-       } else if (!getpwuid_r(uid, &resultbuf, buffer, sizeof(buffer), &result)) {
-               if (sprintf(buf, "%s:%s:%lu:%lu:%s:%s:%s\n",
-                                       resultbuf.pw_name, resultbuf.pw_passwd,
-                                       (unsigned long)(resultbuf.pw_uid),
-                                       (unsigned long)(resultbuf.pw_gid),
-                                       resultbuf.pw_gecos, resultbuf.pw_dir,
-                                       resultbuf.pw_shell) >= 0
-                       ) {
-                       return 0;
+       if (!db->fp) {
+               db->fp = fopen_for_read(db->filename);
+               if (!db->fp) {
+                       return errno;
                }
+               close_on_exec_on(fileno(db->fp));
        }
 
-       return -1;
+       buf = parse_common(db->fp, db, /*no search key:*/ NULL, -1);
+       if (!buf && !errno)
+               errno = ENOENT;
+       return massage_data_for_r_func(db, buffer, buflen, result, buf);
 }
 
-/**********************************************************************/
-
-/* FIXME: we don't have such CONFIG_xx - ?! */
-
-#if defined CONFIG_USE_BB_THREADSAFE_SHADOW && defined PTHREAD_MUTEX_INITIALIZER
-static pthread_mutex_t mylock = PTHREAD_MUTEX_INITIALIZER;
-# define LOCK          pthread_mutex_lock(&mylock)
-# define UNLOCK                pthread_mutex_unlock(&mylock);
-#else
-# define LOCK          ((void) 0)
-# define UNLOCK                ((void) 0)
-#endif
-
-static FILE *pwf /*= NULL*/;
-void setpwent(void)
+int FAST_FUNC getpwent_r(struct passwd *struct_buf, char *buffer, size_t buflen,
+               struct passwd **result)
 {
-       LOCK;
-       if (pwf) {
-               rewind(pwf);
-       }
-       UNLOCK;
-}
-
-void endpwent(void)
-{
-       LOCK;
-       if (pwf) {
-               fclose(pwf);
-               pwf = NULL;
-       }
-       UNLOCK;
+       *result = struct_buf;
+       return getXXent_r(0, buffer, buflen, result);
 }
+#endif
 
+/****** getXXent */
 
-int getpwent_r(struct passwd *__restrict resultbuf,
-                          char *__restrict buffer, size_t buflen,
-                          struct passwd **__restrict result)
+static void* FAST_FUNC getXXent(uintptr_t db_idx)
 {
-       int rv;
-
-       LOCK;
-       *result = NULL;                         /* In case of error... */
+       char *buf;
+       struct passdb *db = &get_S()->db[db_idx];
 
-       if (!pwf) {
-               pwf = fopen_for_read(_PATH_PASSWD);
-               if (!pwf) {
-                       rv = errno;
-                       goto ERR;
+       if (!db->fp) {
+               db->fp = fopen_for_read(db->filename);
+               if (!db->fp) {
+                       return NULL;
                }
+               close_on_exec_on(fileno(db->fp));
        }
 
-       rv = bb__pgsreader(bb__parsepwent, resultbuf, buffer, buflen, pwf);
-       if (!rv) {
-               *result = resultbuf;
-       }
-
- ERR:
-       UNLOCK;
-       return rv;
+       buf = parse_common(db->fp, db, /*no search key:*/ NULL, -1);
+       return massage_data_for_non_r_func(db, buf);
 }
 
-static FILE *grf /*= NULL*/;
-void setgrent(void)
+struct passwd* FAST_FUNC getpwent(void)
 {
-       LOCK;
-       if (grf) {
-               rewind(grf);
-       }
-       UNLOCK;
+       return getXXent(0);
 }
 
-void endgrent(void)
-{
-       LOCK;
-       if (grf) {
-               fclose(grf);
-               grf = NULL;
-       }
-       UNLOCK;
-}
+/****** getXXnam/id */
 
-int getgrent_r(struct group *__restrict resultbuf,
-                          char *__restrict buffer, size_t buflen,
-                          struct group **__restrict result)
+static void* FAST_FUNC getXXnam(const char *name, unsigned db_and_field_pos)
 {
-       int rv;
+       char *buf;
+       struct passdb *db = &get_S()->db[db_and_field_pos >> 2];
 
-       LOCK;
-       *result = NULL;                         /* In case of error... */
-
-       if (!grf) {
-               grf = fopen_for_read(_PATH_GROUP);
-               if (!grf) {
-                       rv = errno;
-                       goto ERR;
-               }
-       }
-
-       rv = bb__pgsreader(bb__parsegrent, resultbuf, buffer, buflen, grf);
-       if (!rv) {
-               *result = resultbuf;
-       }
-
- ERR:
-       UNLOCK;
-       return rv;
+       buf = parse_file(db, name, db_and_field_pos & 3);
+       return massage_data_for_non_r_func(db, buf);
 }
 
-#if ENABLE_USE_BB_SHADOW
-static FILE *spf /*= NULL*/;
-void setspent(void)
+struct passwd* FAST_FUNC getpwnam(const char *name)
 {
-       LOCK;
-       if (spf) {
-               rewind(spf);
-       }
-       UNLOCK;
+       return getXXnam(name, (0 << 2) + 0);
 }
-
-void endspent(void)
+struct group* FAST_FUNC getgrnam(const char *name)
 {
-       LOCK;
-       if (spf) {
-               fclose(spf);
-               spf = NULL;
-       }
-       UNLOCK;
+       return getXXnam(name, (1 << 2) + 0);
 }
-
-int getspent_r(struct spwd *resultbuf, char *buffer,
-                          size_t buflen, struct spwd **result)
+struct passwd* FAST_FUNC getpwuid(uid_t id)
 {
-       int rv;
-
-       LOCK;
-       *result = NULL;                         /* In case of error... */
-
-       if (!spf) {
-               spf = fopen_for_read(_PATH_SHADOW);
-               if (!spf) {
-                       rv = errno;
-                       goto ERR;
-               }
-       }
-
-       rv = bb__pgsreader(bb__parsespent, resultbuf, buffer, buflen, spf);
-       if (!rv) {
-               *result = resultbuf;
-       }
-
- ERR:
-       UNLOCK;
-       return rv;
+       return getXXnam(utoa(id), (0 << 2) + 2);
 }
-#endif
-
-#if 0
-struct passwd *getpwent(void)
+struct group* FAST_FUNC getgrgid(gid_t id)
 {
-       static char line_buff[PWD_BUFFER_SIZE];
-       static struct passwd pwd;
-       struct passwd *result;
-
-       getpwent_r(&pwd, line_buff, sizeof(line_buff), &result);
-       return result;
+       return getXXnam(utoa(id), (1 << 2) + 2);
 }
 
-struct group *getgrent(void)
-{
-       static char line_buff[GRP_BUFFER_SIZE];
-       static struct group gr;
-       struct group *result;
+/****** end/setXXend */
 
-       getgrent_r(&gr, line_buff, sizeof(line_buff), &result);
-       return result;
+void FAST_FUNC endpwent(void)
+{
+       if (has_S && S.db[0].fp) {
+               fclose(S.db[0].fp);
+               S.db[0].fp = NULL;
+       }
 }
-#endif
-
-#if 0 //ENABLE_USE_BB_SHADOW
-struct spwd *getspent(void)
+void FAST_FUNC setpwent(void)
 {
-       static char line_buff[PWD_BUFFER_SIZE];
-       static struct spwd spwd;
-       struct spwd *result;
-
-       getspent_r(&spwd, line_buff, sizeof(line_buff), &result);
-       return result;
+       if (has_S && S.db[0].fp) {
+               rewind(S.db[0].fp);
+       }
 }
-
-struct spwd *sgetspent(const char *string)
+void FAST_FUNC endgrent(void)
 {
-       static char line_buff[PWD_BUFFER_SIZE];
-       static struct spwd spwd;
-       struct spwd *result;
-
-       sgetspent_r(string, &spwd, line_buff, sizeof(line_buff), &result);
-       return result;
+       if (has_S && S.db[1].fp) {
+               fclose(S.db[1].fp);
+               S.db[1].fp = NULL;
+       }
 }
-#endif
 
-static gid_t *getgrouplist_internal(int *ngroups_ptr, const char *user, gid_t gid)
+/****** initgroups and getgrouplist */
+
+static gid_t* FAST_FUNC getgrouplist_internal(int *ngroups_ptr,
+               const char *user, gid_t gid)
 {
-       FILE *grfile;
+       FILE *fp;
        gid_t *group_list;
        int ngroups;
-       struct group group;
-       char buff[PWD_BUFFER_SIZE];
 
        /* We alloc space for 8 gids at a time. */
-       group_list = xmalloc(8 * sizeof(group_list[0]));
+       group_list = xzalloc(8 * sizeof(group_list[0]));
        group_list[0] = gid;
        ngroups = 1;
 
-       grfile = fopen_for_read(_PATH_GROUP);
-       if (grfile) {
-               while (!bb__pgsreader(bb__parsegrent, &group, buff, sizeof(buff), grfile)) {
+       fp = fopen_for_read(_PATH_GROUP);
+       if (fp) {
+               struct passdb *db = &get_S()->db[1];
+               char *buf;
+               while ((buf = parse_common(fp, db, NULL, -1)) != NULL) {
                        char **m;
-                       assert(group.gr_mem); /* Must have at least a NULL terminator. */
+                       struct group group;
+                       if (!convert_to_struct(db, buf, &group))
+                               goto next;
                        if (group.gr_gid == gid)
-                               continue;
+                               goto next;
                        for (m = group.gr_mem; *m; m++) {
                                if (strcmp(*m, user) != 0)
                                        continue;
-                               group_list = xrealloc_vector(group_list, 3, ngroups);
+                               group_list = xrealloc_vector(group_list, /*8=2^3:*/ 3, ngroups);
                                group_list[ngroups++] = group.gr_gid;
-                               break;
+                               goto next;
                        }
+ next:
+                       free(buf);
                }
-               fclose(grfile);
+               fclose(fp);
        }
        *ngroups_ptr = ngroups;
        return group_list;
 }
 
-int initgroups(const char *user, gid_t gid)
+int FAST_FUNC initgroups(const char *user, gid_t gid)
 {
        int ngroups;
        gid_t *group_list = getgrouplist_internal(&ngroups, user, gid);
 
-       if (!group_list)
-               return -1;
-
        ngroups = setgroups(ngroups, group_list);
        free(group_list);
        return ngroups;
 }
 
-/* TODO: uclibc needs this ported to it! */
-int getgrouplist(const char *user, gid_t gid, gid_t *groups, int *ngroups)
+int FAST_FUNC getgrouplist(const char *user, gid_t gid, gid_t *groups, int *ngroups)
 {
        int ngroups_old = *ngroups;
        gid_t *group_list = getgrouplist_internal(ngroups, user, gid);
@@ -682,398 +558,3 @@ int getgrouplist(const char *user, gid_t gid, gid_t *groups, int *ngroups)
        free(group_list);
        return ngroups_old;
 }
-
-int putpwent(const struct passwd *__restrict p, FILE *__restrict f)
-{
-       int rv = -1;
-
-       if (!p || !f) {
-               errno = EINVAL;
-       } else {
-               /* No extra thread locking is needed above what fprintf does. */
-               if (fprintf(f, "%s:%s:%lu:%lu:%s:%s:%s\n",
-                                       p->pw_name, p->pw_passwd,
-                                       (unsigned long)(p->pw_uid),
-                                       (unsigned long)(p->pw_gid),
-                                       p->pw_gecos, p->pw_dir, p->pw_shell) >= 0
-                       ) {
-                       rv = 0;
-               }
-       }
-
-       return rv;
-}
-
-int putgrent(const struct group *__restrict p, FILE *__restrict f)
-{
-       static const char format[] ALIGN1 = ",%s";
-
-       char **m;
-       const char *fmt;
-       int rv = -1;
-
-       if (!p || !f) {                         /* Sigh... glibc checks. */
-               errno = EINVAL;
-       } else {
-               if (fprintf(f, "%s:%s:%lu:",
-                                       p->gr_name, p->gr_passwd,
-                                       (unsigned long)(p->gr_gid)) >= 0
-                       ) {
-
-                       fmt = format + 1;
-
-                       assert(p->gr_mem);
-                       m = p->gr_mem;
-
-                       do {
-                               if (!*m) {
-                                       if (fputc('\n', f) >= 0) {
-                                               rv = 0;
-                                       }
-                                       break;
-                               }
-                               if (fprintf(f, fmt, *m) < 0) {
-                                       break;
-                               }
-                               ++m;
-                               fmt = format;
-                       } while (1);
-
-               }
-
-       }
-
-       return rv;
-}
-
-#if ENABLE_USE_BB_SHADOW
-static const unsigned char _sp_off[] ALIGN1 = {
-       offsetof(struct spwd, sp_lstchg),       /* 2 - not a char ptr */
-       offsetof(struct spwd, sp_min),          /* 3 - not a char ptr */
-       offsetof(struct spwd, sp_max),          /* 4 - not a char ptr */
-       offsetof(struct spwd, sp_warn),         /* 5 - not a char ptr */
-       offsetof(struct spwd, sp_inact),        /* 6 - not a char ptr */
-       offsetof(struct spwd, sp_expire)        /* 7 - not a char ptr */
-};
-
-int putspent(const struct spwd *p, FILE *stream)
-{
-       static const char ld_format[] ALIGN1 = "%ld:";
-
-       const char *f;
-       long x;
-       int i;
-       int rv = -1;
-
-       /* Unlike putpwent and putgrent, glibc does not check the args. */
-       if (fprintf(stream, "%s:%s:", p->sp_namp,
-                               (p->sp_pwdp ? p->sp_pwdp : "")) < 0
-       ) {
-               goto DO_UNLOCK;
-       }
-
-       for (i = 0; i < sizeof(_sp_off); i++) {
-               f = ld_format;
-               x = *(const long *)(((const char *) p) + _sp_off[i]);
-               if (x == -1) {
-                       f += 3;
-               }
-               if (fprintf(stream, f, x) < 0) {
-                       goto DO_UNLOCK;
-               }
-       }
-
-       if ((p->sp_flag != ~0UL) && (fprintf(stream, "%lu", p->sp_flag) < 0)) {
-               goto DO_UNLOCK;
-       }
-
-       if (fputc('\n', stream) > 0) {
-               rv = 0;
-       }
-
-DO_UNLOCK:
-       return rv;
-}
-#endif
-
-/**********************************************************************/
-/* Internal uClibc functions.                                         */
-/**********************************************************************/
-
-static const unsigned char pw_off[] ALIGN1 = {
-       offsetof(struct passwd, pw_name),       /* 0 */
-       offsetof(struct passwd, pw_passwd),     /* 1 */
-       offsetof(struct passwd, pw_uid),        /* 2 - not a char ptr */
-       offsetof(struct passwd, pw_gid),        /* 3 - not a char ptr */
-       offsetof(struct passwd, pw_gecos),      /* 4 */
-       offsetof(struct passwd, pw_dir),        /* 5 */
-       offsetof(struct passwd, pw_shell)       /* 6 */
-};
-
-static int bb__parsepwent(void *data, char *line)
-{
-       char *endptr;
-       char *p;
-       int i;
-
-       i = 0;
-       do {
-               p = ((char *) ((struct passwd *) data)) + pw_off[i];
-
-               if ((i & 6) ^ 2) {      /* i!=2 and i!=3 */
-                       *((char **) p) = line;
-                       if (i==6) {
-                               return 0;
-                       }
-                       /* NOTE: glibc difference - glibc allows omission of
-                        * ':' seperators after the gid field if all remaining
-                        * entries are empty.  We require all separators. */
-                       line = strchr(line, ':');
-                       if (!line) {
-                               break;
-                       }
-               } else {
-                       unsigned long t = strtoul(line, &endptr, 10);
-                       /* Make sure we had at least one digit, and that the
-                        * failing char is the next field seperator ':'.  See
-                        * glibc difference note above. */
-                       /* TODO: Also check for leading whitespace? */
-                       if ((endptr == line) || (*endptr != ':')) {
-                               break;
-                       }
-                       line = endptr;
-                       if (i & 1) {            /* i == 3 -- gid */
-                               *((gid_t *) p) = t;
-                       } else {                        /* i == 2 -- uid */
-                               *((uid_t *) p) = t;
-                       }
-               }
-
-               *line++ = 0;
-               ++i;
-       } while (1);
-
-       return -1;
-}
-
-/**********************************************************************/
-
-static const unsigned char gr_off[] ALIGN1 = {
-       offsetof(struct group, gr_name),        /* 0 */
-       offsetof(struct group, gr_passwd),      /* 1 */
-       offsetof(struct group, gr_gid)          /* 2 - not a char ptr */
-};
-
-static int bb__parsegrent(void *data, char *line)
-{
-       char *endptr;
-       char *p;
-       int i;
-       char **members;
-       char *end_of_buf;
-
-       end_of_buf = ((struct group *) data)->gr_name; /* Evil hack! */
-       i = 0;
-       do {
-               p = ((char *) ((struct group *) data)) + gr_off[i];
-
-               if (i < 2) {
-                       *((char **) p) = line;
-                       line = strchr(line, ':');
-                       if (!line) {
-                               break;
-                       }
-                       *line++ = 0;
-                       ++i;
-               } else {
-                       *((gid_t *) p) = strtoul(line, &endptr, 10);
-
-                       /* NOTE: glibc difference - glibc allows omission of the
-                        * trailing colon when there is no member list.  We treat
-                        * this as an error. */
-
-                       /* Make sure we had at least one digit, and that the
-                        * failing char is the next field seperator ':'.  See
-                        * glibc difference note above. */
-                       if ((endptr == line) || (*endptr != ':')) {
-                               break;
-                       }
-
-                       i = 1;                          /* Count terminating NULL ptr. */
-                       p = endptr;
-
-                       if (p[1]) { /* We have a member list to process. */
-                               /* Overwrite the last ':' with a ',' before counting.
-                                * This allows us to test for initial ',' and adds
-                                * one ',' so that the ',' count equals the member
-                                * count. */
-                               *p = ',';
-                               do {
-                                       /* NOTE: glibc difference - glibc allows and trims leading
-                                        * (but not trailing) space.  We treat this as an error. */
-                                       /* NOTE: glibc difference - glibc allows consecutive and
-                                        * trailing commas, and ignores "empty string" users.  We
-                                        * treat this as an error. */
-                                       if (*p == ',') {
-                                               ++i;
-                                               *p = 0; /* nul-terminate each member string. */
-                                               if (!*++p || (*p == ',') || isspace(*p)) {
-                                                       goto ERR;
-                                               }
-                                       }
-                               } while (*++p);
-                       }
-
-                       /* Now align (p+1), rounding up. */
-                       /* Assumes sizeof(char **) is a power of 2. */
-                       members = (char **)( (((intptr_t) p) + sizeof(char **))
-                                                                & ~((intptr_t)(sizeof(char **) - 1)) );
-
-                       if (((char *)(members + i)) > end_of_buf) {     /* No space. */
-                               break;
-                       }
-
-                       ((struct group *) data)->gr_mem = members;
-
-                       if (--i) {
-                               p = endptr;     /* Pointing to char prior to first member. */
-                               do {
-                                       *members++ = ++p;
-                                       if (!--i) break;
-                                       while (*++p) {}
-                               } while (1);
-                       }
-                       *members = NULL;
-
-                       return 0;
-               }
-       } while (1);
-
- ERR:
-       return -1;
-}
-
-/**********************************************************************/
-
-#if ENABLE_USE_BB_SHADOW
-static const unsigned char sp_off[] ALIGN1 = {
-       offsetof(struct spwd, sp_namp),         /* 0 */
-       offsetof(struct spwd, sp_pwdp),         /* 1 */
-       offsetof(struct spwd, sp_lstchg),       /* 2 - not a char ptr */
-       offsetof(struct spwd, sp_min),          /* 3 - not a char ptr */
-       offsetof(struct spwd, sp_max),          /* 4 - not a char ptr */
-       offsetof(struct spwd, sp_warn),         /* 5 - not a char ptr */
-       offsetof(struct spwd, sp_inact),        /* 6 - not a char ptr */
-       offsetof(struct spwd, sp_expire),       /* 7 - not a char ptr */
-       offsetof(struct spwd, sp_flag)          /* 8 - not a char ptr */
-};
-
-static int bb__parsespent(void *data, char * line)
-{
-       char *endptr;
-       char *p;
-       int i;
-
-       i = 0;
-       do {
-               p = ((char *) ((struct spwd *) data)) + sp_off[i];
-               if (i < 2) {
-                       *((char **) p) = line;
-                       line = strchr(line, ':');
-                       if (!line) {
-                               break;
-                       }
-               } else {
-                       *((long *) p) = (long) strtoul(line, &endptr, 10);
-
-                       if (endptr == line) {
-                               *((long *) p) = ((i != 8) ? -1L : ((long)(~0UL)));
-                       }
-
-                       line = endptr;
-
-                       if (i == 8) {
-                               if (!*endptr) {
-                                       return 0;
-                               }
-                               break;
-                       }
-
-                       if (*endptr != ':') {
-                               break;
-                       }
-
-               }
-
-               *line++ = 0;
-               ++i;
-       } while (1);
-
-       return EINVAL;
-}
-#endif
-
-/**********************************************************************/
-
-/* Reads until if EOF, or until if finds a line which fits in the buffer
- * and for which the parser function succeeds.
- *
- * Returns 0 on success and ENOENT for end-of-file (glibc concession).
- */
-
-static int bb__pgsreader(int (*parserfunc)(void *d, char *line), void *data,
-                               char *__restrict line_buff, size_t buflen, FILE *f)
-{
-       int line_len;
-       int skip;
-       int rv = ERANGE;
-
-       if (buflen < PWD_BUFFER_SIZE) {
-               errno = rv;
-       } else {
-               skip = 0;
-               do {
-                       if (!fgets(line_buff, buflen, f)) {
-                               if (feof(f)) {
-                                       rv = ENOENT;
-                               }
-                               break;
-                       }
-
-                       line_len = strlen(line_buff) - 1; /* strlen() must be > 0. */
-                       if (line_buff[line_len] == '\n') {
-                               line_buff[line_len] = 0;
-                       } else if (line_len + 2 == buflen) { /* line too long */
-                               ++skip;
-                               continue;
-                       }
-
-                       if (skip) {
-                               --skip;
-                               continue;
-                       }
-
-                       /* NOTE: glibc difference - glibc strips leading whitespace from
-                        * records.  We do not allow leading whitespace. */
-
-                       /* Skip empty lines, comment lines, and lines with leading
-                        * whitespace. */
-                       if (*line_buff && (*line_buff != '#') && !isspace(*line_buff)) {
-                               if (parserfunc == bb__parsegrent) {     /* Do evil group hack. */
-                                       /* The group entry parsing function needs to know where
-                                        * the end of the buffer is so that it can construct the
-                                        * group member ptr table. */
-                                       ((struct group *) data)->gr_name = line_buff + buflen;
-                               }
-
-                               if (!parserfunc(data, line_buff)) {
-                                       rv = 0;
-                                       break;
-                               }
-                       }
-               } while (1);
-
-       }
-
-       return rv;
-}