diff options
Diffstat (limited to 'REORG.TODO/nss/nss_files/files-XXX.c')
| -rw-r--r-- | REORG.TODO/nss/nss_files/files-XXX.c | 300 |
1 files changed, 300 insertions, 0 deletions
diff --git a/REORG.TODO/nss/nss_files/files-XXX.c b/REORG.TODO/nss/nss_files/files-XXX.c new file mode 100644 index 0000000000..265331ef21 --- /dev/null +++ b/REORG.TODO/nss/nss_files/files-XXX.c @@ -0,0 +1,300 @@ +/* Common code for file-based databases in nss_files module. + Copyright (C) 1996-2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <stdio.h> +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <libc-lock.h> +#include "nsswitch.h" + +#include <kernel-features.h> + +/* These symbols are defined by the including source file: + + ENTNAME -- database name of the structure and functions (hostent, pwent). + STRUCTURE -- struct name, define only if not ENTNAME (passwd, group). + DATABASE -- string of the database file's name ("hosts", "passwd"). + + NEED_H_ERRNO - defined iff an arg `int *herrnop' is used. + + Also see files-parse.c. +*/ + +#define ENTNAME_r CONCAT(ENTNAME,_r) + +#define DATAFILE "/etc/" DATABASE + +#ifdef NEED_H_ERRNO +# include <netdb.h> +# define H_ERRNO_PROTO , int *herrnop +# define H_ERRNO_ARG , herrnop +# define H_ERRNO_SET(val) (*herrnop = (val)) +#else +# define H_ERRNO_PROTO +# define H_ERRNO_ARG +# define H_ERRNO_SET(val) ((void) 0) +#endif + +#ifndef EXTRA_ARGS +# define EXTRA_ARGS +# define EXTRA_ARGS_DECL +# define EXTRA_ARGS_VALUE +#endif + +/* Locks the static variables in this file. */ +__libc_lock_define_initialized (static, lock) + +/* Maintenance of the stream open on the database file. For getXXent + operations the stream needs to be held open across calls, the other + getXXbyYY operations all use their own stream. */ + +static FILE *stream; + +/* Open database file if not already opened. */ +static enum nss_status +internal_setent (FILE **stream) +{ + enum nss_status status = NSS_STATUS_SUCCESS; + + if (*stream == NULL) + { + *stream = fopen (DATAFILE, "rce"); + + if (*stream == NULL) + status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL; + } + else + rewind (*stream); + + return status; +} + + +/* Thread-safe, exported version of that. */ +enum nss_status +CONCAT(_nss_files_set,ENTNAME) (int stayopen) +{ + enum nss_status status; + + __libc_lock_lock (lock); + + status = internal_setent (&stream); + + __libc_lock_unlock (lock); + + return status; +} + + +/* Close the database file. */ +static void +internal_endent (FILE **stream) +{ + if (*stream != NULL) + { + fclose (*stream); + *stream = NULL; + } +} + + +/* Thread-safe, exported version of that. */ +enum nss_status +CONCAT(_nss_files_end,ENTNAME) (void) +{ + __libc_lock_lock (lock); + + internal_endent (&stream); + + __libc_lock_unlock (lock); + + return NSS_STATUS_SUCCESS; +} + + +typedef enum +{ + gcr_ok = 0, + gcr_error = -1, + gcr_overflow = -2 +} get_contents_ret; + +/* Hack around the fact that fgets only accepts int sizes. */ +static get_contents_ret +get_contents (char *linebuf, size_t len, FILE *stream) +{ + size_t remaining_len = len; + char *curbuf = linebuf; + + do + { + int curlen = ((remaining_len > (size_t) INT_MAX) ? INT_MAX + : remaining_len); + + /* Terminate the line so that we can test for overflow. */ + ((unsigned char *) curbuf)[curlen - 1] = 0xff; + + char *p = fgets_unlocked (curbuf, curlen, stream); + + /* EOF or read error. */ + if (p == NULL) + return gcr_error; + + /* Done reading in the line. */ + if (((unsigned char *) curbuf)[curlen - 1] == 0xff) + return gcr_ok; + + /* Drop the terminating '\0'. */ + remaining_len -= curlen - 1; + curbuf += curlen - 1; + } + /* fgets copies one less than the input length. Our last iteration is of + REMAINING_LEN and once that is done, REMAINING_LEN is decremented by + REMAINING_LEN - 1, leaving the result as 1. */ + while (remaining_len > 1); + + /* This means that the current buffer was not large enough. */ + return gcr_overflow; +} + +/* Parsing the database file into `struct STRUCTURE' data structures. */ +static enum nss_status +internal_getent (FILE *stream, struct STRUCTURE *result, + char *buffer, size_t buflen, int *errnop H_ERRNO_PROTO + EXTRA_ARGS_DECL) +{ + char *p; + struct parser_data *data = (void *) buffer; + size_t linebuflen = buffer + buflen - data->linebuffer; + int parse_result; + + if (buflen < sizeof *data + 2) + { + *errnop = ERANGE; + H_ERRNO_SET (NETDB_INTERNAL); + return NSS_STATUS_TRYAGAIN; + } + + do + { + get_contents_ret r = get_contents (data->linebuffer, linebuflen, stream); + + if (r == gcr_error) + { + /* End of file or read error. */ + H_ERRNO_SET (HOST_NOT_FOUND); + return NSS_STATUS_NOTFOUND; + } + + if (r == gcr_overflow) + { + /* The line is too long. Give the user the opportunity to + enlarge the buffer. */ + *errnop = ERANGE; + H_ERRNO_SET (NETDB_INTERNAL); + return NSS_STATUS_TRYAGAIN; + } + + /* Everything OK. Now skip leading blanks. */ + p = data->linebuffer; + while (isspace (*p)) + ++p; + } + while (*p == '\0' || *p == '#' /* Ignore empty and comment lines. */ + /* Parse the line. If it is invalid, loop to get the next + line of the file to parse. */ + || ! (parse_result = parse_line (p, result, data, buflen, errnop + EXTRA_ARGS))); + + if (__glibc_unlikely (parse_result == -1)) + { + H_ERRNO_SET (NETDB_INTERNAL); + return NSS_STATUS_TRYAGAIN; + } + + /* Filled in RESULT with the next entry from the database file. */ + return NSS_STATUS_SUCCESS; +} + + +/* Return the next entry from the database file, doing locking. */ +enum nss_status +CONCAT(_nss_files_get,ENTNAME_r) (struct STRUCTURE *result, char *buffer, + size_t buflen, int *errnop H_ERRNO_PROTO) +{ + /* Return next entry in host file. */ + enum nss_status status = NSS_STATUS_SUCCESS; + + __libc_lock_lock (lock); + + /* Be prepared that the set*ent function was not called before. */ + if (stream == NULL) + { + int save_errno = errno; + + status = internal_setent (&stream); + + __set_errno (save_errno); + } + + if (status == NSS_STATUS_SUCCESS) + status = internal_getent (stream, result, buffer, buflen, errnop + H_ERRNO_ARG EXTRA_ARGS_VALUE); + + __libc_lock_unlock (lock); + + return status; +} + +/* Macro for defining lookup functions for this file-based database. + + NAME is the name of the lookup; e.g. `hostbyname'. + + DB_CHAR, KEYPATTERN, KEYSIZE are ignored here but used by db-XXX.c + e.g. `1 + sizeof (id) * 4'. + + PROTO is the potentially empty list of other parameters. + + BREAK_IF_MATCH is a block of code which compares `struct STRUCTURE *result' + to the lookup key arguments and does `break;' if they match. */ + +#define DB_LOOKUP(name, db_char, keysize, keypattern, break_if_match, proto...)\ +enum nss_status \ +_nss_files_get##name##_r (proto, \ + struct STRUCTURE *result, char *buffer, \ + size_t buflen, int *errnop H_ERRNO_PROTO) \ +{ \ + enum nss_status status; \ + FILE *stream = NULL; \ + \ + /* Open file. */ \ + status = internal_setent (&stream); \ + \ + if (status == NSS_STATUS_SUCCESS) \ + { \ + while ((status = internal_getent (stream, result, buffer, buflen, errnop \ + H_ERRNO_ARG EXTRA_ARGS_VALUE)) \ + == NSS_STATUS_SUCCESS) \ + { break_if_match } \ + \ + internal_endent (&stream); \ + } \ + \ + return status; \ +} |