From 2add4235ef674988948155f9a8f60a8c7b09bcff Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Thu, 16 Jul 2020 17:31:20 +0200 Subject: [PATCH 08/11] gshadow: Implement fgetsgent_r using __nss_fgetent_r (bug 20338) Tested-by: Carlos O'Donell Reviewed-by: Carlos O'Donell --- gshadow/Makefile | 2 +- gshadow/fgetsgent_r.c | 41 ++-------- gshadow/tst-fgetsgent_r.c | 191 ++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 198 insertions(+), 36 deletions(-) create mode 100644 gshadow/tst-fgetsgent_r.c diff -rupN a/gshadow/Makefile b/gshadow/Makefile --- a/gshadow/Makefile 2018-08-01 01:10:47.000000000 -0400 +++ b/gshadow/Makefile 2020-09-14 18:00:57.167145887 -0400 @@ -26,7 +26,7 @@ headers = gshadow.h routines = getsgent getsgnam sgetsgent fgetsgent putsgent \ getsgent_r getsgnam_r sgetsgent_r fgetsgent_r -tests = tst-gshadow tst-putsgent +tests = tst-gshadow tst-putsgent tst-fgetsgent_r CFLAGS-getsgent_r.c += -fexceptions CFLAGS-getsgent.c += -fexceptions diff -rupN a/gshadow/fgetsgent_r.c b/gshadow/fgetsgent_r.c --- a/gshadow/fgetsgent_r.c 2018-08-01 01:10:47.000000000 -0400 +++ b/gshadow/fgetsgent_r.c 2020-09-14 18:45:59.189353065 -0400 @@ -36,40 +36,11 @@ int __fgetsgent_r (FILE *stream, struct sgrp *resbuf, char *buffer, size_t buflen, struct sgrp **result) { - char *p; - - _IO_flockfile (stream); - do - { - buffer[buflen - 1] = '\xff'; - p = fgets_unlocked (buffer, buflen, stream); - if (p == NULL && feof_unlocked (stream)) - { - _IO_funlockfile (stream); - *result = NULL; - __set_errno (ENOENT); - return errno; - } - if (p == NULL || buffer[buflen - 1] != '\xff') - { - _IO_funlockfile (stream); - *result = NULL; - __set_errno (ERANGE); - return errno; - } - - /* Skip leading blanks. */ - 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_line (buffer, (void *) resbuf, (void *) buffer, buflen, - &errno)); - - _IO_funlockfile (stream); - - *result = resbuf; - return 0; + int ret = __nss_fgetent_r (stream, resbuf, buffer, buflen, parse_line); + if (ret == 0) + *result = resbuf; + else + *result = NULL; + return ret; } weak_alias (__fgetsgent_r, fgetsgent_r) diff -rupN a/gshadow/tst-fgetsgent_r.c b/gshadow/tst-fgetsgent_r.c --- a/gshadow/tst-fgetsgent_r.c 1969-12-31 19:00:00.000000000 -0500 +++ b/gshadow/tst-fgetsgent_r.c 2020-09-14 18:00:57.174146151 -0400 @@ -0,0 +1,191 @@ +/* Test for fgetsgent_r and buffer sizes. + Copyright (C) 2020 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 + . */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Turn a parsed struct back into a line string. The returned string + should be freed. */ +static char * +format_ent (const struct sgrp *e) +{ + struct xmemstream stream; + xopen_memstream (&stream); + TEST_COMPARE (putsgent (e, stream.out), 0); + xfclose_memstream (&stream); + return stream.buffer; +} + +/* An entry in the input file along with the expected output. */ +struct input +{ + const char *line; /* Line in the file. */ + const char *expected; /* Expected output. NULL if skipped. */ +}; + +const struct input inputs[] = + { + /* Regular entries. */ + { "g1:x1::\n", "g1:x1::\n" }, + { "g2:x2:a1:\n", "g2:x2:a1:\n" }, + { "g3:x3:a2:u1\n", "g3:x3:a2:u1\n" }, + { "g4:x4:a3,a4:u2,u3,u4\n", "g4:x4:a3,a4:u2,u3,u4\n" }, + + /* Comments and empty lines. */ + { "\n", NULL }, + { " \n", NULL }, + { "\t\n", NULL }, + { "#g:x::\n", NULL }, + { " #g:x::\n", NULL }, + { "\t#g:x::\n", NULL }, + { " \t#g:x::\n", NULL }, + + /* Marker for synchronization. */ + { "g5:x5::\n", "g5:x5::\n" }, + + /* Leading whitespace. */ + { " g6:x6::\n", "g6:x6::\n" }, + { "\tg7:x7::\n", "g7:x7::\n" }, + + /* This is expected to trigger buffer exhaustion during parsing + (bug 20338). */ + { + "g8:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:u5,u6,u7,u8,u9:\n", + "g8:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx:u5,u6,u7,u8,u9:\n", + }, + { + "g9:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx::a5,a6,a7,a8,a9,a10\n", + "g9:xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx::a5,a6,a7,a8,a9,a10\n", + }, + }; + +/* Writes the test data to a temporary file and returns its name. The + returned pointer should be freed. */ +static char * +create_test_file (void) +{ + char *path; + int fd = create_temp_file ("tst-fgetsgent_r-", &path); + FILE *fp = fdopen (fd, "w"); + TEST_VERIFY_EXIT (fp != NULL); + + for (size_t i = 0; i < array_length (inputs); ++i) + fputs (inputs[i].line, fp); + + xfclose (fp); + return path; +} + +/* Read the test file with the indicated start buffer size. Return + true if the buffer size had to be increased during reading. */ +static bool +run_test (const char *path, size_t buffer_size) +{ + bool resized = false; + FILE *fp = xfopen (path, "r"); + + /* This avoids repeated lseek system calls (bug 26257). */ + TEST_COMPARE (fseeko64 (fp, 0, SEEK_SET), 0); + + size_t i = 0; + while (true) + { + /* Skip over unused expected entries. */ + while (i < array_length (inputs) && inputs[i].expected == NULL) + ++i; + + /* Store the data on the heap, to help valgrind to detect + invalid accesses. */ + struct sgrp *result_storage = xmalloc (sizeof (*result_storage)); + char *buffer = xmalloc (buffer_size); + struct sgrp **result_pointer_storage + = xmalloc (sizeof (*result_pointer_storage)); + + int ret = fgetsgent_r (fp, result_storage, buffer, buffer_size, + result_pointer_storage); + if (ret == 0) + { + TEST_VERIFY (*result_pointer_storage != NULL); + TEST_VERIFY (i < array_length (inputs)); + if (*result_pointer_storage != NULL + && i < array_length (inputs)) + { + char * actual = format_ent (*result_pointer_storage); + TEST_COMPARE_STRING (inputs[i].expected, actual); + free (actual); + ++i; + } + else + break; + } + else + { + TEST_VERIFY (*result_pointer_storage == NULL); + TEST_COMPARE (ret, errno); + + if (ret == ENOENT) + { + TEST_COMPARE (i, array_length (inputs)); + free (result_pointer_storage); + free (buffer); + free (result_storage); + break; + } + else if (ret == ERANGE) + { + resized = true; + ++buffer_size; + } + else + FAIL_EXIT1 ("read failure: %m"); + } + + free (result_pointer_storage); + free (buffer); + free (result_storage); + } + + return resized; +} + +static int +do_test (void) +{ + char *path = create_test_file (); + + for (size_t buffer_size = 3; ; ++buffer_size) + { + bool resized = run_test (path, buffer_size); + if (!resized) + break; + } + + free (path); + + return 0; +} + +#include