[source] procd: procd_send_signal use signal names

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/37bb463daa21e2c97365c6543b2bfdfe673c5baa

commit 37bb463daa21e2c97365c6543b2bfdfe673c5baa
Author: Kevin Darbyshire-Bryant <ldir at darbyshire-bryant.me.uk>
AuthorDate: Tue Jan 2 14:34:51 2018 +0000

    procd: procd_send_signal use signal names
    
    Usage documentation for 'procd_send_signal' states "The signal is SIGHUP
    by default, and must be specified by NAME."  Make actual behaviour match
    the stated documented behaviour.
    
    https://wiki.openwrt.org/inbox/procd-init-scripts
    
    Suggested-by: Jo-Philip Wich <jow at mein.io>
    Signed-off-by: Kevin Darbyshire-Bryant <ldir at darbyshire-bryant.me.uk>
---
 package/system/procd/Makefile       | 2 +-
 package/system/procd/files/procd.sh | 4 ++++
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/package/system/procd/Makefile b/package/system/procd/Makefile
index bffed81..7c8a166 100644
--- a/package/system/procd/Makefile
+++ b/package/system/procd/Makefile
@@ -8,7 +8,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=procd
-PKG_RELEASE:=1
+PKG_RELEASE:=2
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(LEDE_GIT)/project/procd.git
diff --git a/package/system/procd/files/procd.sh b/package/system/procd/files/procd.sh
index b8d3513..b4b6faa 100644
--- a/package/system/procd/files/procd.sh
+++ b/package/system/procd/files/procd.sh
@@ -413,6 +413,10 @@ _procd_send_signal() {
 	local instance="$2"
 	local signal="$3"
 
+	case "$signal" in
+		[A-Z]*)	signal="$(kill -l "$signal" 2>/dev/null)" || return 1;;
+	esac
+
 	json_init
 	json_add_string name "$service"
 	[ -n "$instance" -a "$instance" != "*" ] && json_add_string instance "$instance"