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From fee19fa8d4f6f351e5a76f5801884880249d6a45 Mon Sep 17 00:00:00 2001 |
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From: Chris Liddell <chris.liddell@artifex.com> |
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Date: Wed, 5 Oct 2016 09:55:55 +0100 |
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Subject: [PATCH] Bug 697178: Add a file permissions callback |
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|
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For the rare occasions when the graphics library directly opens a file |
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(currently for reading), this allows us to apply any restrictions on |
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file access normally applied in the interpteter. |
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--- |
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base/gsicc_manage.c | 10 ++++++---- |
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base/gslibctx.c | 12 +++++++++++- |
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base/gslibctx.h | 7 +++++++ |
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psi/imain.c | 2 ++ |
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psi/int.mak | 2 +- |
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psi/zfile.c | 19 +++++++++++++++++++ |
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psi/zfile.h | 7 +++++++ |
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7 files changed, 53 insertions(+), 6 deletions(-) |
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|
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diff --git a/base/gsicc_manage.c b/base/gsicc_manage.c |
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index 931c2a6..e9c09c3 100644 |
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--- a/base/gsicc_manage.c |
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+++ b/base/gsicc_manage.c |
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@@ -1124,10 +1124,12 @@ gsicc_open_search(const char* pname, int namelen, gs_memory_t *mem_gc, |
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} |
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|
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/* First just try it like it is */ |
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- str = sfopen(pname, "r", mem_gc); |
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- if (str != NULL) { |
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- *strp = str; |
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- return 0; |
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+ if (gs_check_file_permission(mem_gc, pname, namelen, "r") >= 0) { |
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+ str = sfopen(pname, "r", mem_gc); |
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+ if (str != NULL) { |
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+ *strp = str; |
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+ return 0; |
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+ } |
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} |
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|
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/* If that fails, try %rom% */ /* FIXME: Not sure this is needed or correct */ |
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diff --git a/base/gslibctx.c b/base/gslibctx.c |
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index fa4432a..f2c13e3 100644 |
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--- a/base/gslibctx.c |
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+++ b/base/gslibctx.c |
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@@ -183,7 +183,7 @@ int gs_lib_ctx_init( gs_memory_t *mem ) |
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mem->gs_lib_ctx = NULL; |
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return -1; |
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} |
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- |
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+ pio->client_check_file_permission = NULL; |
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gp_get_realtime(pio->real_time_0); |
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|
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/* Set scanconverter to 1 (default) */ |
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@@ -336,3 +336,13 @@ void errflush(const gs_memory_t *mem) |
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fflush(mem->gs_lib_ctx->fstderr); |
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/* else nothing to flush */ |
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} |
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+ |
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+int |
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+gs_check_file_permission (gs_memory_t *mem, const char *fname, const int len, const char *permission) |
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+{ |
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+ int code = 0; |
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+ if (mem->gs_lib_ctx->client_check_file_permission != NULL) { |
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+ code = mem->gs_lib_ctx->client_check_file_permission(mem, fname, len, permission); |
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+ } |
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+ return code; |
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+} |
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diff --git a/base/gslibctx.h b/base/gslibctx.h |
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index 84ec205..55eb4a6 100644 |
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--- a/base/gslibctx.h |
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+++ b/base/gslibctx.h |
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@@ -32,6 +32,9 @@ typedef struct gs_fapi_server_s gs_fapi_server; |
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# define gs_font_dir_DEFINED |
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typedef struct gs_font_dir_s gs_font_dir; |
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#endif |
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+ |
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+typedef int (*client_check_file_permission_t) (gs_memory_t *mem, const char *fname, const int len, const char *permission); |
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+ |
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typedef struct gs_lib_ctx_s |
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{ |
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gs_memory_t *memory; /* mem->gs_lib_ctx->memory == mem */ |
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@@ -61,6 +64,7 @@ typedef struct gs_lib_ctx_s |
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struct gx_io_device_s **io_device_table; |
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int io_device_table_count; |
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int io_device_table_size; |
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+ client_check_file_permission_t client_check_file_permission; |
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/* Define the default value of AccurateScreens that affects setscreen |
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and setcolorscreen. */ |
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bool screen_accurate_screens; |
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@@ -132,6 +136,9 @@ int |
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gs_lib_ctx_get_default_device_list(const gs_memory_t *mem, char** dev_list_str, |
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int *list_str_len); |
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|
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+int |
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+gs_check_file_permission (gs_memory_t *mem, const char *fname, const int len, const char *permission); |
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+ |
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#define IS_LIBCTX_STDOUT(mem, f) (f == mem->gs_lib_ctx->fstdout) |
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#define IS_LIBCTX_STDERR(mem, f) (f == mem->gs_lib_ctx->fstderr) |
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|
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diff --git a/psi/imain.c b/psi/imain.c |
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index 9a9bb5d..6874128 100644 |
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--- a/psi/imain.c |
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+++ b/psi/imain.c |
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@@ -57,6 +57,7 @@ |
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#include "ivmspace.h" |
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#include "idisp.h" /* for setting display device callback */ |
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#include "iplugin.h" |
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+#include "zfile.h" |
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|
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#ifdef PACIFY_VALGRIND |
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#include "valgrind.h" |
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@@ -212,6 +213,7 @@ gs_main_init1(gs_main_instance * minst) |
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"the_gs_name_table"); |
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if (code < 0) |
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return code; |
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+ mem->gs_lib_ctx->client_check_file_permission = z_check_file_permissions; |
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} |
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code = obj_init(&minst->i_ctx_p, &idmem); /* requires name_init */ |
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if (code < 0) |
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diff --git a/psi/int.mak b/psi/int.mak |
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index 4654afc..bb30d51 100644 |
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--- a/psi/int.mak |
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+++ b/psi/int.mak |
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@@ -2024,7 +2024,7 @@ $(PSOBJ)imain.$(OBJ) : $(PSSRC)imain.c $(GH) $(memory__h) $(string__h)\ |
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$(ialloc_h) $(iconf_h) $(idebug_h) $(idict_h) $(idisp_h) $(iinit_h)\ |
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$(iname_h) $(interp_h) $(iplugin_h) $(isave_h) $(iscan_h) $(ivmspace_h)\ |
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$(iinit_h) $(main_h) $(oper_h) $(ostack_h)\ |
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- $(sfilter_h) $(store_h) $(stream_h) $(strimpl_h)\ |
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+ $(sfilter_h) $(store_h) $(stream_h) $(strimpl_h) $(zfile_h)\ |
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$(INT_MAK) $(MAKEDIRS) |
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$(PSCC) $(PSO_)imain.$(OBJ) $(C_) $(PSSRC)imain.c |
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|
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diff --git a/psi/zfile.c b/psi/zfile.c |
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index b6caea2..fd94f67 100644 |
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--- a/psi/zfile.c |
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+++ b/psi/zfile.c |
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@@ -197,6 +197,25 @@ check_file_permissions(i_ctx_t *i_ctx_p, const char *fname, int len, |
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return check_file_permissions_reduced(i_ctx_p, fname_reduced, rlen, permitgroup); |
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} |
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|
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+/* z_check_file_permissions: see zfile.h for explanation |
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+ */ |
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+int |
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+z_check_file_permissions(gs_memory_t *mem, const char *fname, const int len, const char *permission) |
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+{ |
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+ i_ctx_t *i_ctx_p = get_minst_from_memory(mem)->i_ctx_p; |
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+ gs_parsed_file_name_t pname; |
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+ const char *permitgroup = permission[0] == 'r' ? "PermitFileReading" : "PermitFileWriting"; |
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+ int code = gs_parse_file_name(&pname, fname, len, imemory); |
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+ if (code < 0) |
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+ return code; |
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+ |
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+ if (pname.iodev && i_ctx_p->LockFilePermissions && strcmp(pname.iodev->dname, "%pipe%") == 0) |
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+ return gs_error_invalidfileaccess; |
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+ |
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+ code = check_file_permissions(i_ctx_p, fname, len, permitgroup); |
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+ return code; |
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+} |
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+ |
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/* <name_string> <access_string> file <file> */ |
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int /* exported for zsysvm.c */ |
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zfile(i_ctx_t *i_ctx_p) |
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diff --git a/psi/zfile.h b/psi/zfile.h |
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index fdf1373..a9399c7 100644 |
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--- a/psi/zfile.h |
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+++ b/psi/zfile.h |
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@@ -22,4 +22,11 @@ |
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int zopen_file(i_ctx_t *i_ctx_p, const gs_parsed_file_name_t *pfn, |
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const char *file_access, stream **ps, gs_memory_t *mem); |
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|
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+/* z_check_file_permissions: a callback (via mem->gs_lib_ctx->client_check_file_permission) |
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+ * to allow applying the above permissions checks when opening file(s) from |
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+ * the graphics library |
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+ */ |
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+int |
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+z_check_file_permissions(gs_memory_t *mem, const char *fname, |
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+ const int len, const char *permission); |
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#endif |
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-- |
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2.7.4 |
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