From 551f1ae54837754ea893d08175fafc85f63ba8b8 Mon Sep 17 00:00:00 2001
From: Joachim Wiberg <troglobit@gmail.com>
Date: Sat, 13 Apr 2024 10:26:57 +0200
Subject: [PATCH] libsrx: two new helpers, unquoute() and fgetkey()

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>
---
 src/confd/src/infix-dhcp.c | 43 +++++++++--------------------------
 src/libsrx/src/helpers.c   | 46 ++++++++++++++++++++++++++++++++++++++
 src/libsrx/src/helpers.h   |  3 +++
 3 files changed, 59 insertions(+), 33 deletions(-)

diff --git a/src/confd/src/infix-dhcp.c b/src/confd/src/infix-dhcp.c
index 6cd1abbb..99dac801 100644
--- a/src/confd/src/infix-dhcp.c
+++ b/src/confd/src/infix-dhcp.c
@@ -82,47 +82,24 @@ static char *fqdn(const char *value, char *str, size_t len)
 	return str;
 }
 
-static char *unquote(char *buf)
-{
-	char q = buf[0];
-	char *ptr;
-
-	if (q != '"' && q != '\'')
-		return buf;
-
-	ptr = &buf[strlen(buf) - 1];
-	if (*ptr == q) {
-		*ptr = 0;
-		buf++;
-	}
-
-	return buf;
-}
-
 static char *os_name_version(char *str, size_t len)
 {
-	char buf[256];
-	FILE *fp;
+	char *val;
 
 	if (!str || !len)
 		return NULL;
 
-	fp = fopen("/etc/os-release", "r");
-	if (!fp)
-		return NULL;
-
 	str[0] = 0;
-	while (fgets(buf, sizeof(buf), fp)) {
-		chomp(buf);
-		if (!strncmp(buf, "NAME=", 5))
-			snprintf(str, len, "-V \"%.32s ", unquote(&buf[5]));
-		if (!strncmp(buf, "VERSION=", 8)) {
-			strlcat(str, unquote(&buf[8]), len);
-			strlcat(str, "\"", len);
-			break;
-		}
+
+	val = fgetkey("/etc/os-release", "NAME");
+	if (val)
+		snprintf(str, len, "-V \"%.32s ", val);
+
+	val = fgetkey("/etc/os-release", "VERSION");
+	if (val) {
+		strlcat(str, val, len);
+		strlcat(str, "\"", len);
 	}
-	fclose(fp);
 
 	if (strlen(str) > 0 && str[strlen(str) - 1] != '"') {
 		str[0] = 0;
diff --git a/src/libsrx/src/helpers.c b/src/libsrx/src/helpers.c
index 0ccade20..0ffbc359 100644
--- a/src/libsrx/src/helpers.c
+++ b/src/libsrx/src/helpers.c
@@ -215,3 +215,49 @@ int writesf(const char *str, const char *mode, const char *fmt, ...)
 	return fclose(fp);
 }
 
+char *unquote(char *buf)
+{
+	char q = buf[0];
+	char *ptr;
+
+	if (q != '"' && q != '\'')
+		return buf;
+
+	ptr = &buf[strlen(buf) - 1];
+	if (*ptr == q) {
+		*ptr = 0;
+		buf++;
+	}
+
+	return buf;
+}
+
+/*
+ * Reads file, line by line, lookging for key="val".
+ * Returns val, or NULL.
+ */
+char *fgetkey(const char *file, const char *key)
+{
+	static char line[256];
+	int len = strlen(key);
+	char *ptr = NULL;
+	FILE *fp;
+
+	fp = fopen(file, "r");
+	if (!fp)
+		return NULL;
+
+	while (fgets(line, sizeof(line), fp)) {
+		chomp(line);
+		if (strncmp(line, key, len))
+			continue;
+		if (line[len] != '=')
+			continue;
+
+		ptr = unquote(line + len + 1); /* Skip 'key=' */
+		break;
+	}
+	fclose(fp);
+
+	return ptr;
+}
diff --git a/src/libsrx/src/helpers.h b/src/libsrx/src/helpers.h
index 56cb712b..0c197531 100644
--- a/src/libsrx/src/helpers.h
+++ b/src/libsrx/src/helpers.h
@@ -26,4 +26,7 @@ int writedf(int value, const char *mode, const char *fmt, ...)
 int writesf(const char *str, const char *mode, const char *fmt, ...)
 	__attribute__ ((format (printf, 3, 4)));
 
+char *unquote(char *buf);
+char *fgetkey(const char *file, const char *key);
+
 #endif /* CONFD_HELPERS_H_ */