Backported of:
From 3782dfda5fc4f45a19b1ce1b01ecf7206a3d304a Mon Sep 17 00:00:00 2001
From: Daniel Stenberg <daniel@haxx.se>
Date: Wed, 25 May 2022 10:09:53 +0200
Subject: [PATCH 1/3] fopen: add Curl_fopen() for better overwriting of files
---
lib/Makefile.inc | 4 +-
lib/altsvc.c | 22 +++-------
lib/cookie.c | 16 ++-----
lib/fopen.c | 106 +++++++++++++++++++++++++++++++++++++++++++++++
lib/fopen.h | 28 +++++++++++++
lib/hsts.c | 22 +++-------
6 files changed, 152 insertions(+), 46 deletions(-)
create mode 100644 lib/fopen.c
create mode 100644 lib/fopen.h
diff --git a/lib/Makefile.inc b/lib/Makefile.inc
index 6d35704..7dac605 100644
--- a/lib/Makefile.inc
+++ b/lib/Makefile.inc
@@ -50,7 +50,7 @@ LIB_CFILES = altsvc.c amigaos.c asyn-ares.c asyn-thread.c base64.c \
curl_gethostname.c curl_gssapi.c curl_memrchr.c curl_multibyte.c \
curl_ntlm_core.c curl_ntlm_wb.c curl_path.c curl_range.c curl_rtmp.c \
curl_sasl.c curl_sspi.c curl_threads.c dict.c dotdot.c easy.c escape.c \
- file.c fileinfo.c formdata.c ftp.c url.c ftplistparser.c getenv.c getinfo.c \
+ file.c fileinfo.c fopen.c formdata.c ftp.c url.c ftplistparser.c getenv.c getinfo.c \
gopher.c hash.c hmac.c hostasyn.c hostcheck.c hostip.c hostip4.c hostip6.c \
hostsyn.c http.c http2.c http_chunks.c http_digest.c http_negotiate.c \
http_ntlm.c http_proxy.c idn_win32.c if2ip.c imap.c inet_ntop.c inet_pton.c \
@@ -70,7 +70,7 @@ LIB_HFILES = altsvc.h amigaos.h arpa_telnet.h asyn.h conncache.h connect.h \
curl_memrchr.h curl_multibyte.h curl_ntlm_core.h curl_ntlm_wb.h curl_path.h \
curl_printf.h curl_range.h curl_rtmp.h curl_sasl.h curl_krb5.h curl_setup.h \
curl_setup_once.h curl_sha256.h curl_sspi.h curl_threads.h curlx.h dict.h \
- dotdot.h easyif.h escape.h file.h fileinfo.h formdata.h ftp.h url.h \
+ dotdot.h easyif.h escape.h file.h fileinfo.h fopen.h formdata.h ftp.h url.h \
ftplistparser.h getinfo.h gopher.h hash.h hostcheck.h hostip.h http.h \
http2.h http_chunks.h http_digest.h http_negotiate.h http_ntlm.h \
http_proxy.h if2ip.h imap.h inet_ntop.h inet_pton.h llist.h memdebug.h \
diff --git a/lib/altsvc.c b/lib/altsvc.c
index 4ab77fd..97249b2 100644
--- a/lib/altsvc.c
+++ b/lib/altsvc.c
@@ -34,7 +34,7 @@
#include "parsedate.h"
#include "sendf.h"
#include "warnless.h"
-#include "rand.h"
+#include "fopen.h"
#include "rename.h"
/* The last 3 #include files should be in this order */
@@ -329,8 +329,7 @@ CURLcode Curl_altsvc_save(struct Curl_easy *data,
struct Curl_llist_element *n;
CURLcode result = CURLE_OK;
FILE *out;
- char *tempstore;
- unsigned char randsuffix[9];
+ char *tempstore = NULL;
if(!altsvc)
/* no cache activated */
@@ -344,17 +343,8 @@ CURLcode Curl_altsvc_save(struct Curl_easy *data,
/* marked as read-only, no file or zero length file name */
return CURLE_OK;
- if(Curl_rand_hex(data, randsuffix, sizeof(randsuffix)))
- return CURLE_FAILED_INIT;
-
- tempstore = aprintf("%s.%s.tmp", file, randsuffix);
- if(!tempstore)
- return CURLE_OUT_OF_MEMORY;
-
- out = fopen(tempstore, FOPEN_WRITETEXT);
- if(!out)
- result = CURLE_WRITE_ERROR;
- else {
+ result = Curl_fopen(data, file, &out, &tempstore);
+ if(!result) {
fputs("# Your alt-svc cache. https://curl.se/docs/alt-svc.html\n"
"# This file was generated by libcurl! Edit at your own risk.\n",
out);
@@ -366,10 +356,10 @@ CURLcode Curl_altsvc_save(struct Curl_easy *data,
break;
}
fclose(out);
- if(!result && Curl_rename(tempstore, file))
+ if(!result && tempstore && Curl_rename(tempstore, file))
result = CURLE_WRITE_ERROR;
- if(result)
+ if(result && tempstore)
unlink(tempstore);
}
free(tempstore);
diff --git a/lib/cookie.c b/lib/cookie.c
index 1d1bf9b..2dc6314 100644
--- a/lib/cookie.c
+++ b/lib/cookie.c
@@ -99,6 +99,7 @@ Example set of cookies:
#include "parsedate.h"
#include "rand.h"
#include "rename.h"
+#include "fopen.h"
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
@@ -1534,17 +1535,8 @@ static int cookie_output(struct Curl_easy *data,
use_stdout = TRUE;
}
else {
- unsigned char randsuffix[9];
-
- if(Curl_rand_hex(data, randsuffix, sizeof(randsuffix)))
- return 2;
-
- tempstore = aprintf("%s.%s.tmp", filename, randsuffix);
- if(!tempstore)
- return 1;
-
- out = fopen(tempstore, FOPEN_WRITETEXT);
- if(!out)
+ error = Curl_fopen(data, filename, &out, &tempstore);
+ if(error)
goto error;
}
@@ -1591,7 +1583,7 @@ static int cookie_output(struct Curl_easy *data,
if(!use_stdout) {
fclose(out);
out = NULL;
- if(Curl_rename(tempstore, filename)) {
+ if(tempstore && Curl_rename(tempstore, filename)) {
unlink(tempstore);
goto error;
}
diff --git a/lib/fopen.c b/lib/fopen.c
new file mode 100644
index 0000000..92dc31d
--- /dev/null
+++ b/lib/fopen.c
@@ -0,0 +1,106 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+#include "curl_setup.h"
+
+#if !defined(CURL_DISABLE_COOKIES) && !defined(CURL_DISABLE_ALTSVC) && \
+ !defined(CURL_DISABLE_HSTS)
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif
+
+#include "urldata.h"
+#include "rand.h"
+#include "fopen.h"
+/* The last 3 #include files should be in this order */
+#include "curl_printf.h"
+#include "curl_memory.h"
+#include "memdebug.h"
+
+/*
+ * Curl_fopen() opens a file for writing with a temp name, to be renamed
+ * to the final name when completed. If there is an existing file using this
+ * name at the time of the open, this function will clone the mode from that
+ * file. if 'tempname' is non-NULL, it needs a rename after the file is
+ * written.
+ */
+CURLcode Curl_fopen(struct Curl_easy *data, const char *filename,
+ FILE **fh, char **tempname)
+{
+ CURLcode result = CURLE_WRITE_ERROR;
+ unsigned char randsuffix[9];
+ char *tempstore = NULL;
+ struct_stat sb, nsb;
+ int fd = -1;
+ *tempname = NULL;
+
+ if(stat(filename, &sb) == -1 || !S_ISREG(sb.st_mode)) {
+ /* a non-regular file, fallback to direct fopen() */
+ *fh = fopen(filename, FOPEN_WRITETEXT);
+ if(*fh)
+ return CURLE_OK;
+ goto fail;
+ }
+
+ result = Curl_rand_hex(data, randsuffix, sizeof(randsuffix));
+ if(result)
+ goto fail;
+
+ tempstore = aprintf("%s.%s.tmp", filename, randsuffix);
+ if(!tempstore) {
+ result = CURLE_OUT_OF_MEMORY;
+ goto fail;
+ }
+
+ result = CURLE_WRITE_ERROR;
+ fd = open(tempstore, O_WRONLY | O_CREAT | O_EXCL, 0600);
+ if(fd == -1)
+ goto fail;
+
+ if((fstat(fd, &nsb) != -1) &&
+ (nsb.st_uid == sb.st_uid) && (nsb.st_gid == sb.st_gid)) {
+ /* if the user and group are the same, clone the original mode */
+ if(fchmod(fd, sb.st_mode) == -1)
+ goto fail;
+ }
+
+ *fh = fdopen(fd, FOPEN_WRITETEXT);
+ if(!*fh)
+ goto fail;
+
+ *tempname = tempstore;
+ return CURLE_OK;
+
+fail:
+ if(fd != -1) {
+ close(fd);
+ unlink(tempstore);
+ }
+
+ free(tempstore);
+
+ *tempname = NULL;
+ return result;
+}
+
+#endif /* ! disabled */
diff --git a/lib/fopen.h b/lib/fopen.h
new file mode 100644
index 0000000..1020f3c
--- /dev/null
+++ b/lib/fopen.h
@@ -0,0 +1,28 @@
+#ifndef HEADER_CURL_FOPEN_H
+#define HEADER_CURL_FOPEN_H
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at https://curl.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ***************************************************************************/
+
+CURLcode Curl_fopen(struct Curl_easy *data, const char *filename,
+ FILE **fh, char **tempname);
+
+#endif
diff --git a/lib/hsts.c b/lib/hsts.c
index 6f77128..00bd943 100644
--- a/lib/hsts.c
+++ b/lib/hsts.c
@@ -35,7 +35,7 @@
#include "sendf.h"
#include "strtoofft.h"
#include "parsedate.h"
-#include "rand.h"
+#include "fopen.h"
#include "rename.h"
/* The last 3 #include files should be in this order */
@@ -318,8 +318,7 @@ CURLcode Curl_hsts_save(struct Curl_easy *data, struct hsts *h,
struct Curl_llist_element *n;
CURLcode result = CURLE_OK;
FILE *out;
- char *tempstore;
- unsigned char randsuffix[9];
+ char *tempstore = NULL;
if(!h)
/* no cache activated */
@@ -333,17 +332,8 @@ CURLcode Curl_hsts_save(struct Curl_easy *data, struct hsts *h,
/* marked as read-only, no file or zero length file name */
goto skipsave;
- if(Curl_rand_hex(data, randsuffix, sizeof(randsuffix)))
- return CURLE_FAILED_INIT;
-
- tempstore = aprintf("%s.%s.tmp", file, randsuffix);
- if(!tempstore)
- return CURLE_OUT_OF_MEMORY;
-
- out = fopen(tempstore, FOPEN_WRITETEXT);
- if(!out)
- result = CURLE_WRITE_ERROR;
- else {
+ result = Curl_fopen(data, file, &out, &tempstore);
+ if(!result) {
fputs("# Your HSTS cache. https://curl.se/docs/hsts.html\n"
"# This file was generated by libcurl! Edit at your own risk.\n",
out);
@@ -355,10 +345,10 @@ CURLcode Curl_hsts_save(struct Curl_easy *data, struct hsts *h,
break;
}
fclose(out);
- if(!result && Curl_rename(tempstore, file))
+ if(!result && tempstore && Curl_rename(tempstore, file))
result = CURLE_WRITE_ERROR;
- if(result)
+ if(result && tempstore)
unlink(tempstore);
}
free(tempstore);
--
2.25.1
