sysctl: Add sysctl module with /proc/sys helpers

Moved sysctl get/set funcs from flowtop to separated sysctl module.

Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

4 files changed, 76 insertions, 54 deletions

diff --git a/flowtop.c b/flowtop.c
index 8cf2fd3..bf2e585 100644
--- a/flowtop.c
+++ b/flowtop.c
@@ -39,6 +39,7 @@
 #include "pkt_buff.h"
 #include "screen.h"
 #include "proc.h"
+#include "sysctl.h"
 
 struct flow_entry {
 	uint32_t flow_id, use, status;
@@ -222,60 +223,6 @@ static const struct nfct_filter_ipv6 filter_ipv6 = {
 	.mask = { 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff },
 };
 
-#define SYS_PATH "/proc/sys/"
-
-static int sysctl_set_int(char *file, int value)
-{
-	char path[PATH_MAX];
-	char str[64];
-	ssize_t ret;
-	int fd;
-
-	strncpy(path, SYS_PATH, PATH_MAX);
-	strncat(path, file, PATH_MAX - sizeof(SYS_PATH) - 1);
-
-	fd = open(path, O_WRONLY);
-	if (unlikely(fd < 0))
-		return -1;
-
-	ret = snprintf(str, 63, "%d", value);
-	if (ret < 0) {
-		close(fd);
-		return -1;
-	}
-
-	ret = write(fd, str, strlen(str));
-
-	close(fd);
-	return ret <= 0 ? -1 : 0;
-}
-
-static int sysctl_get_int(char *file, int *value)
-{
-	char path[PATH_MAX];
-	char str[64];
-	ssize_t ret;
-	int fd;
-
-	strncpy(path, SYS_PATH, PATH_MAX);
-	strncat(path, file, PATH_MAX - sizeof(SYS_PATH) - 1);
-
-	fd = open(path, O_RDONLY);
-	if (fd < 0)
-		return -1;
-
-	ret = read(fd, str, sizeof(str));
-	if (ret > 0) {
-		*value = atoi(str);
-		ret = 0;
-	} else {
-		ret = -1;
-	}
-
-	close(fd);
-	return ret;
-}
-
 static void signal_handler(int number)
 {
 	switch (number) {
diff --git a/flowtop/Makefile b/flowtop/Makefile
index 85cb0b6..edb5829 100644
--- a/flowtop/Makefile
+++ b/flowtop/Makefile
@@ -23,6 +23,7 @@ flowtop-objs =	xmalloc.o \
 		tprintf.o \
 		screen.o \
 		die.o \
+		sysctl.o \
 		flowtop.o
 
 ifeq ($(CONFIG_GEOIP), 1)
diff --git a/sysctl.c b/sysctl.c
new file mode 100644
index 0000000..283d403
--- /dev/null
+++ b/sysctl.c
@@ -0,0 +1,67 @@
+/*
+ * sysctl - sysctl set/get helpers
+ * Subject to the GPL, version 2.
+ */
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/limits.h>
+
+#include "built_in.h"
+
+#define SYS_PATH "/proc/sys/"
+
+int sysctl_set_int(const char *file, int value)
+{
+	char path[PATH_MAX];
+	char str[64];
+	ssize_t ret;
+	int fd;
+
+	strncpy(path, SYS_PATH, PATH_MAX);
+	strncat(path, file, PATH_MAX - sizeof(SYS_PATH) - 1);
+
+	fd = open(path, O_WRONLY);
+	if (unlikely(fd < 0))
+		return -1;
+
+	ret = snprintf(str, 63, "%d", value);
+	if (ret < 0) {
+		close(fd);
+		return -1;
+	}
+
+	ret = write(fd, str, strlen(str));
+
+	close(fd);
+	return ret <= 0 ? -1 : 0;
+}
+
+int sysctl_get_int(const char *file, int *value)
+{
+	char path[PATH_MAX];
+	char str[64];
+	ssize_t ret;
+	int fd;
+
+	strncpy(path, SYS_PATH, PATH_MAX);
+	strncat(path, file, PATH_MAX - sizeof(SYS_PATH) - 1);
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return -1;
+
+	ret = read(fd, str, sizeof(str));
+	if (ret > 0) {
+		*value = atoi(str);
+		ret = 0;
+	} else {
+		ret = -1;
+	}
+
+	close(fd);
+	return ret;
+}
diff --git a/sysctl.h b/sysctl.h
new file mode 100644
index 0000000..2f88f0a
--- /dev/null
+++ b/sysctl.h
@@ -0,0 +1,7 @@
+#ifndef SYSCTL_H
+#define SYSCTL_H
+
+int sysctl_set_int(const char *file, int value);
+int sysctl_get_int(const char *file, int *value);
+
+#endif