From 437116f238d30f1b9d7b19d8d4364ed937817dff Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Fri, 16 Feb 2018 20:10:25 +0100
Subject: [PATCH] wg: allow in-line comments

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 contrib/reresolve-dns/reresolve-dns.sh |  5 +++--
 src/config.c                           | 17 +++++++++++------
 src/wg-quick.bash                      |  7 ++++---
 src/wg.8                               |  4 ++--
 4 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/contrib/reresolve-dns/reresolve-dns.sh b/contrib/reresolve-dns/reresolve-dns.sh
index 7f913ab..5b9394b 100755
--- a/contrib/reresolve-dns/reresolve-dns.sh
+++ b/contrib/reresolve-dns/reresolve-dns.sh
@@ -29,8 +29,9 @@ reset_peer_section() {
 
 reset_peer_section
 while read -r line || [[ -n $line ]]; do
-	key="${line%%=*}"; key="${key##*([[:space:]])}"; key="${key%%*([[:space:]])}"
-	value="${line#*=}"; value="${value##*([[:space:]])}"; value="${value%%*([[:space:]])}"
+	stripped="${line%%\#*}"
+	key="${stripped%%=*}"; key="${key##*([[:space:]])}"; key="${key%%*([[:space:]])}"
+	value="${stripped#*=}"; value="${value##*([[:space:]])}"; value="${value%%*([[:space:]])}"
 	[[ $key == "["* ]] && { process_peer; reset_peer_section; }
 	[[ $key == "[Peer]" ]] && PEER_SECTION=1
 	if [[ $PEER_SECTION -eq 1 ]]; then
diff --git a/src/config.c b/src/config.c
index 0407b36..93c39fa 100644
--- a/src/config.c
+++ b/src/config.c
@@ -417,25 +417,30 @@ error:
 
 bool config_read_line(struct config_ctx *ctx, const char *input)
 {
-	size_t len = strlen(input), cleaned_len = 0;
-	char *line = calloc(len + 1, sizeof(char));
+	size_t len, cleaned_len = 0;
+	char *line, *comment;
 	bool ret = true;
 
+	/* This is what strchrnull is for, but that isn't portable. */
+	comment = strchr(input, COMMENT_CHAR);
+	if (comment)
+		len = comment - input;
+	else
+		len = strlen(input);
+
+	line = calloc(len + 1, sizeof(char));
 	if (!line) {
 		perror("calloc");
 		ret = false;
 		goto out;
 	}
-	if (!len)
-		goto out;
+
 	for (size_t i = 0; i < len; ++i) {
 		if (!isspace(input[i]))
 			line[cleaned_len++] = input[i];
 	}
 	if (!cleaned_len)
 		goto out;
-	if (line[0] == COMMENT_CHAR)
-		goto out;
 	ret = process_line(ctx, line);
 out:
 	free(line);
diff --git a/src/wg-quick.bash b/src/wg-quick.bash
index 80921bf..af72f7d 100755
--- a/src/wg-quick.bash
+++ b/src/wg-quick.bash
@@ -27,7 +27,7 @@ PROGRAM="${0##*/}"
 ARGS=( "$@" )
 
 parse_options() {
-	local interface_section=0 line key value
+	local interface_section=0 line key value stripped
 	CONFIG_FILE="$1"
 	[[ $CONFIG_FILE =~ ^[a-zA-Z0-9_=+.-]{1,15}$ ]] && CONFIG_FILE="/etc/wireguard/$CONFIG_FILE.conf"
 	[[ -e $CONFIG_FILE ]] || die "\`$CONFIG_FILE' does not exist"
@@ -37,8 +37,9 @@ parse_options() {
 	INTERFACE="${BASH_REMATCH[2]}"
 	shopt -s nocasematch
 	while read -r line || [[ -n $line ]]; do
-		key="${line%%=*}"; key="${key##*([[:space:]])}"; key="${key%%*([[:space:]])}"
-		value="${line#*=}"; value="${value##*([[:space:]])}"; value="${value%%*([[:space:]])}"
+		stripped="${line%%\#*}"
+		key="${stripped%%=*}"; key="${key##*([[:space:]])}"; key="${key%%*([[:space:]])}"
+		value="${stripped#*=}"; value="${value##*([[:space:]])}"; value="${value%%*([[:space:]])}"
 		[[ $key == "["* ]] && interface_section=0
 		[[ $key == "[Interface]" ]] && interface_section=1
 		if [[ $interface_section -eq 1 ]]; then
diff --git a/src/wg.8 b/src/wg.8
index 612fb4e..ebfb7f6 100644
--- a/src/wg.8
+++ b/src/wg.8
@@ -165,8 +165,8 @@ when unspecified, this option is off. Most users will not need this. Optional.
 
 .SH CONFIGURATION FILE FORMAT EXAMPLE
 This example may be used as a model for writing configuration files, following an
-INI-like syntax. Lines that start with a '#' are considered comments and are thus
-ignored.
+INI-like syntax. Characters after and including a '#' are considered comments and
+are thus ignored.
 
     [Interface]
 .br