diff options
| -rw-r--r-- | include/nss_files.h | 60 | ||||
| -rw-r--r-- | nss/Makefile | 2 | ||||
| -rw-r--r-- | nss/Versions | 4 | ||||
| -rw-r--r-- | nss/nss_files/files-XXX.c | 67 | ||||
| -rw-r--r-- | nss/nss_files/files-alias.c | 69 | ||||
| -rw-r--r-- | nss/nss_files/files-hosts.c | 4 | ||||
| -rw-r--r-- | nss/nss_files_data.c | 161 |
7 files changed, 259 insertions, 108 deletions
diff --git a/include/nss_files.h b/include/nss_files.h index 6a0dcdb..7bf1951 100644 --- a/include/nss_files.h +++ b/include/nss_files.h @@ -20,6 +20,9 @@ #define _NSS_FILES_H #include <stdio.h> +#if IS_IN (libc) +#include <libc-lock.h> +#endif /* Open PATH for reading, as a data source for nss_files. */ FILE *__nss_files_fopen (const char *path); @@ -47,6 +50,63 @@ int __nss_readline_seek (FILE *fp, off64_t offset) attribute_hidden; int __nss_parse_line_result (FILE *fp, off64_t offset, int parse_line_result); libc_hidden_proto (__nss_parse_line_result) +/* Per-file data. Used by the *ent functions that need to preserve + state across calls. */ +struct nss_files_per_file_data +{ + FILE *stream; +#if IS_IN (libc) + /* The size of locks changes between libc and nss_files, so this + member must be last and is only available in libc. */ + __libc_lock_define (, lock); +#endif +}; + +/* File index for __nss_files_data_get. */ +enum nss_files_file + { + nss_file_aliasent, + nss_file_etherent, + nss_file_grent, + nss_file_hostent, + nss_file_netent, + nss_file_protoent, + nss_file_pwent, + nss_file_rpcent, + nss_file_servent, + nss_file_sgent, + nss_file_spent, + + nss_file_count + }; + +/* Obtains a pointer to the per-file data for FILE, which is written + to *PDATA, and tries to open the file at PATH for it. On success, + returns NSS_STATUS_SUCCESS, and the caller must later call + __nss_files_data_put. On failure, NSS_STATUS_TRYAGAIN is returned, + and *ERRNOP and *HERRNOP are updated if these pointers are not + null. */ +enum nss_status __nss_files_data_open (struct nss_files_per_file_data **pdata, + enum nss_files_file file, + const char *path, + int *errnop, int *herrnop); +libc_hidden_proto (__nss_files_data_open) + +/* Unlock the per-file data, previously obtained by + __nss_files_data_open. */ +void __nss_files_data_put (struct nss_files_per_file_data *data); +libc_hidden_proto (__nss_files_data_put) + +/* Performs the set*ent operation for FILE. PATH is the file to + open. */ +enum nss_status __nss_files_data_setent (enum nss_files_file file, + const char *path); +libc_hidden_proto (__nss_files_data_setent) + +/* Performs the end*ent operation for FILE. */ +enum nss_status __nss_files_data_endent (enum nss_files_file file); +libc_hidden_proto (__nss_files_data_endent) + struct parser_data; /* Instances of the parse_line function from diff --git a/nss/Makefile b/nss/Makefile index 9682a31..271a0e7 100644 --- a/nss/Makefile +++ b/nss/Makefile @@ -31,7 +31,7 @@ routines = nsswitch getnssent getnssent_r digits_dots \ compat-lookup nss_hash nss_files_fopen \ nss_readline nss_parse_line_result \ nss_fgetent_r nss_module nss_action \ - nss_action_parse nss_database + nss_action_parse nss_database nss_files_data # These are the databases that go through nss dispatch. # Caution: if you add a database here, you must add its real name diff --git a/nss/Versions b/nss/Versions index fdddea1..7b040b4 100644 --- a/nss/Versions +++ b/nss/Versions @@ -19,6 +19,10 @@ libc { __nss_services_lookup2; __nss_next2; __nss_lookup; __nss_hash; __nss_database_get; __nss_files_fopen; __nss_readline; __nss_parse_line_result; + __nss_files_data_endent; + __nss_files_data_open; + __nss_files_data_put; + __nss_files_data_setent; } } diff --git a/nss/nss_files/files-XXX.c b/nss/nss_files/files-XXX.c index b4b989d..91553d7 100644 --- a/nss/nss_files/files-XXX.c +++ b/nss/nss_files/files-XXX.c @@ -45,10 +45,12 @@ # include <netdb.h> # define H_ERRNO_PROTO , int *herrnop # define H_ERRNO_ARG , herrnop +# define H_ERRNO_ARG_OR_NULL herrnop # define H_ERRNO_SET(val) (*herrnop = (val)) #else # define H_ERRNO_PROTO # define H_ERRNO_ARG +# define H_ERRNO_ARG_OR_NULL NULL # define H_ERRNO_SET(val) ((void) 0) #endif @@ -58,15 +60,11 @@ # 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) @@ -91,41 +89,13 @@ internal_setent (FILE **stream) 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; - } + return __nss_files_data_setent (CONCAT (nss_file_, ENTNAME), DATAFILE); } - -/* 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; + return __nss_files_data_endent (CONCAT (nss_file_, ENTNAME)); } @@ -194,26 +164,19 @@ 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); + struct nss_files_per_file_data *data; + enum nss_status status = __nss_files_data_open (&data, + CONCAT (nss_file_, ENTNAME), + DATAFILE, + errnop, H_ERRNO_ARG_OR_NULL); + if (status != NSS_STATUS_SUCCESS) + return status; - __libc_lock_unlock (lock); + status = internal_getent (data->stream, result, buffer, buflen, errnop + H_ERRNO_ARG EXTRA_ARGS_VALUE); + __nss_files_data_put (data); return status; } @@ -248,7 +211,7 @@ _nss_files_get##name##_r (proto, \ == NSS_STATUS_SUCCESS) \ { break_if_match } \ \ - internal_endent (&stream); \ + fclose (stream); \ } \ \ return status; \ diff --git a/nss/nss_files/files-alias.c b/nss/nss_files/files-alias.c index 30971bf..9624b62 100644 --- a/nss/nss_files/files-alias.c +++ b/nss/nss_files/files-alias.c @@ -33,16 +33,11 @@ NSS_DECLARE_MODULE_FUNCTIONS (files) -/* 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; - - static enum nss_status internal_setent (FILE **stream) { @@ -66,41 +61,13 @@ internal_setent (FILE **stream) enum nss_status _nss_files_setaliasent (void) { - 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; - } + return __nss_files_data_setent (nss_file_aliasent, "/etc/aliases"); } - -/* Thread-safe, exported version of that. */ enum nss_status _nss_files_endaliasent (void) { - __libc_lock_lock (lock); - - internal_endent (&stream); - - __libc_lock_unlock (lock); - - return NSS_STATUS_SUCCESS; + return __nss_files_data_endent (nss_file_aliasent); } /* Parsing the database file into `struct aliasent' data structures. */ @@ -369,26 +336,22 @@ _nss_files_getaliasent_r (struct aliasent *result, char *buffer, size_t buflen, int *errnop) { /* Return next entry in host file. */ - enum nss_status status = NSS_STATUS_SUCCESS; - __libc_lock_lock (lock); + struct nss_files_per_file_data *data; + enum nss_status status = __nss_files_data_open (&data, nss_file_aliasent, + "/etc/aliases", errnop, NULL); + if (status != NSS_STATUS_SUCCESS) + return status; - /* Be prepared that the set*ent function was not called before. */ - if (stream == NULL) - status = internal_setent (&stream); + result->alias_local = 1; - if (status == NSS_STATUS_SUCCESS) - { - result->alias_local = 1; - - /* Read lines until we get a definite result. */ - do - status = get_next_alias (stream, NULL, result, buffer, buflen, errnop); - while (status == NSS_STATUS_RETURN); - } - - __libc_lock_unlock (lock); + /* Read lines until we get a definite result. */ + do + status = get_next_alias (data->stream, NULL, result, buffer, buflen, + errnop); + while (status == NSS_STATUS_RETURN); + __nss_files_data_put (data); return status; } @@ -418,9 +381,9 @@ _nss_files_getaliasbyname_r (const char *name, struct aliasent *result, do status = get_next_alias (stream, name, result, buffer, buflen, errnop); while (status == NSS_STATUS_RETURN); - } - internal_endent (&stream); + fclose (stream); + } return status; } diff --git a/nss/nss_files/files-hosts.c b/nss/nss_files/files-hosts.c index 2b47ec3..1dd51d1 100644 --- a/nss/nss_files/files-hosts.c +++ b/nss/nss_files/files-hosts.c @@ -349,7 +349,7 @@ _nss_files_gethostbyname3_r (const char *name, int af, struct hostent *result, status = gethostbyname3_multi (stream, name, af, result, buffer, buflen, errnop, herrnop); - internal_endent (&stream); + fclose (stream); } if (canonp && status == NSS_STATUS_SUCCESS) @@ -475,7 +475,7 @@ _nss_files_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat, status = NSS_STATUS_SUCCESS; } - internal_endent (&stream); + fclose (stream); } else if (status == NSS_STATUS_TRYAGAIN) { diff --git a/nss/nss_files_data.c b/nss/nss_files_data.c new file mode 100644 index 0000000..80fbfe5 --- /dev/null +++ b/nss/nss_files_data.c @@ -0,0 +1,161 @@ +/* Returns a pointer to the global nss_files data structure. + Copyright (C) 2021 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 + <https://www.gnu.org/licenses/>. */ + +#include <nss_files.h> + +#include <allocate_once.h> +#include <errno.h> +#include <netdb.h> +#include <nss.h> +#include <stdlib.h> + +/* This collects all per file-data. */ +struct nss_files_data +{ + struct nss_files_per_file_data files[nss_file_count]; +}; + +/* For use with allocate_once. */ +static void *nss_files_global; +static void * +nss_files_global_allocate (void *closure) +{ + struct nss_files_data *result = malloc (sizeof (*result)); + if (result != NULL) + { + for (int i = 0; i < nss_file_count; ++i) + { + result->files[i].stream = NULL; + __libc_lock_init (result->files[i].lock); + } + } + return result; +} +/* Like __nss_files_data_open, but does not perform the open call. */ +static enum nss_status +__nss_files_data_get (struct nss_files_per_file_data **pdata, + enum nss_files_file file, int *errnop, int *herrnop) +{ + struct nss_files_data *data = allocate_once (&nss_files_global, + nss_files_global_allocate, + NULL, NULL); + if (data == NULL) + { + if (errnop != NULL) + *errnop = errno; + if (herrnop != NULL) + { + __set_h_errno (NETDB_INTERNAL); + *herrnop = NETDB_INTERNAL; + } + return NSS_STATUS_TRYAGAIN; + } + + *pdata = &data->files[file]; + __libc_lock_lock ((*pdata)->lock); + return NSS_STATUS_SUCCESS; +} + +/* Helper function for opening the backing file at PATH. */ +static enum nss_status +__nss_files_data_internal_open (struct nss_files_per_file_data *data, + const char *path) +{ + enum nss_status status = NSS_STATUS_SUCCESS; + + if (data->stream == NULL) + { + data->stream = __nss_files_fopen (path); + + if (data->stream == NULL) + status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL; + } + + return status; +} + + +enum nss_status +__nss_files_data_open (struct nss_files_per_file_data **pdata, + enum nss_files_file file, const char *path, + int *errnop, int *herrnop) +{ + enum nss_status status = __nss_files_data_get (pdata, file, errnop, herrnop); + if (status != NSS_STATUS_SUCCESS) + return status; + + /* Be prepared that the set*ent function was not called before. */ + if ((*pdata)->stream == NULL) + { + int saved_errno = errno; + status = __nss_files_data_internal_open (*pdata, path); + __set_errno (saved_errno); + if (status != NSS_STATUS_SUCCESS) + __nss_files_data_put (*pdata); + } + + return status; +} + +libc_hidden_def (__nss_files_data_open) + +void +__nss_files_data_put (struct nss_files_per_file_data *data) +{ + __libc_lock_unlock (data->lock); +} +libc_hidden_def (__nss_files_data_put) + +enum nss_status +__nss_files_data_setent (enum nss_files_file file, const char *path) +{ + struct nss_files_per_file_data *data; + enum nss_status status = __nss_files_data_get (&data, file, NULL, NULL); + if (status != NSS_STATUS_SUCCESS) + return status; + + if (data->stream == NULL) + status = __nss_files_data_internal_open (data, path); + else + rewind (data->stream); + + __nss_files_data_put (data); + return status; +} +libc_hidden_def (__nss_files_data_setent) + +enum nss_status +__nss_files_data_endent (enum nss_files_file file) +{ + /* No cleanup is necessary if not initialized. */ + struct nss_files_data *data = atomic_load_acquire (&nss_files_global); + if (data == NULL) + return NSS_STATUS_SUCCESS; + + struct nss_files_per_file_data *fdata = &data->files[file]; + __libc_lock_lock (fdata->lock); + if (fdata->stream != NULL) + { + fclose (fdata->stream); + fdata->stream = NULL; + } + __libc_lock_unlock (fdata->lock); + + return NSS_STATUS_SUCCESS; +} +libc_hidden_def (__nss_files_data_endent) |