patches/openwrt: add patch for procd for process check

This fixes restarts of hostapd process by netifd when wpad (hostapd)
program file is removed/replaced.

This happes on update and tiggers start of new hostapd instance while
old one is still running.

patches/openwrt/wip/0010-Patch-netifd-process-detection.patch

+From 816bdf25140d76ff563f67c753d8392eff19b2d9 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Karel=20Ko=C4=8D=C3=AD?= <karel.koci@nic.cz>
+Date: Thu, 28 May 2020 11:54:37 +0200
+Subject: [PATCH] Improve netifd process detection
+
+---
+ package/network/config/netifd/Makefile        |  2 +-
+ ...pid_path-to-work-with-delted-file-as.patch | 69 +++++++++++++++++++
+ 2 files changed, 70 insertions(+), 1 deletion(-)
+ create mode 100644 package/network/config/netifd/patches/0001-utils-fix-check_pid_path-to-work-with-delted-file-as.patch
+
+diff --git a/package/network/config/netifd/Makefile b/package/network/config/netifd/Makefile
+index 31640c80cd..0edd27795b 100644
+--- a/package/network/config/netifd/Makefile
++++ b/package/network/config/netifd/Makefile
+@@ -1,7 +1,7 @@
+ include $(TOPDIR)/rules.mk
+ 
+ PKG_NAME:=netifd
+-PKG_RELEASE:=1
++PKG_RELEASE:=2
+ 
+ PKG_SOURCE_PROTO:=git
+ PKG_SOURCE_URL=$(PROJECT_GIT)/project/netifd.git
+diff --git a/package/network/config/netifd/patches/0001-utils-fix-check_pid_path-to-work-with-delted-file-as.patch b/package/network/config/netifd/patches/0001-utils-fix-check_pid_path-to-work-with-delted-file-as.patch
+new file mode 100644
+index 0000000000..82a6441399
+--- /dev/null
++++ b/package/network/config/netifd/patches/0001-utils-fix-check_pid_path-to-work-with-delted-file-as.patch
+@@ -0,0 +1,69 @@
++From 8ce3d13d9ba56543c2d627fd429fab171b40994e Mon Sep 17 00:00:00 2001
++From: =?UTF-8?q?Karel=20Ko=C4=8D=C3=AD?= <cynerd@email.cz>
++Date: Thu, 28 May 2020 10:43:44 +0200
++Subject: [PATCH] utils: fix check_pid_path to work with delted file as well
++MIME-Version: 1.0
++Content-Type: text/plain; charset=UTF-8
++Content-Transfer-Encoding: 8bit
++
++check_pid_patch is checking if process with given PID and executable
++path is running. If this code fails the rest of the code can be
++convinced that program is no longer running and possibly spawns new
++instance that can collide with already running one. This behavior was
++reproduced with hostapd.
++
++Symbolic link exe in process subdirectory in /proc points to original
++executable. The problem is that it reads as original path plus string
++' (deleted)' if file is removed. The process is still running but
++original file is no longer available on files ystem.
++
++This behavior is triggered not only when file is removed (unlinked) but
++also when file is replaced. This happens clearly on package update. In
++general this happens any time all references (hard links) to file are
++removed from file system.
++
++This is not ultimate fix as exe link points to any last reference on
++file system with preference for original one. The problem is if there
++are multiple references and the original one is removed. This can be
++reproduced just by copying executable (hard linking) and unlinking the
++original one. In such case exe link would point to copy and not to
++original deleted one.
++
++Signed-off-by: Karel Kočí <cynerd@email.cz>
++---
++ utils.c | 11 ++++++++---
++ 1 file changed, 8 insertions(+), 3 deletions(-)
++
++diff --git a/utils.c b/utils.c
++index ba26952..4f40b4b 100644
++--- a/utils.c
+++++ b/utils.c
++@@ -176,6 +176,8 @@ crc32_file(FILE *fp)
++ 
++ bool check_pid_path(int pid, const char *exe)
++ {
+++	const char deleted[] = " (deleted)";
+++	const int deleted_len = strlen(deleted);
++ 	int proc_exe_len;
++ 	int exe_len = strlen(exe);
++ 
++@@ -191,10 +193,13 @@ bool check_pid_path(int pid, const char *exe)
++ 	proc_exe_len = readlink(proc_exe, proc_exe_buf, exe_len);
++ #endif
++ 
++-	if (proc_exe_len != exe_len)
+++	if (proc_exe_len == exe_len)
+++		return !memcmp(exe, proc_exe_buf, exe_len);
+++	else if (proc_exe_len == exe_len + deleted_len)
+++		return !memcmp(exe, proc_exe_buf, exe_len) &&
+++			!memcmp(exe + exe_len, deleted, deleted_len);
+++	else
++ 		return false;
++-
++-	return !memcmp(exe, proc_exe_buf, exe_len);
++ }
++ 
++ static const char * const uci_validate_name[__BLOBMSG_TYPE_LAST] = {
++-- 
++2.26.2
++
+-- 
+2.26.2
+