initial checkin of unix domain socket tracer

1 files changed, 95 insertions, 0 deletions

diff --git a/utils.c b/utils.c
new file mode 100644
index 0000000..0c763bc
--- /dev/null
+++ b/utils.c
@@ -0,0 +1,95 @@
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "utils.h"
+
+#define MAX_UNIX_FDS	32
+
+#define LOG(fmt, args ...) \
+	fprintf(stderr, ">>> UDTRACE: " fmt, ## args)
+
+/***********************************************************************
+ * Utility functions
+ ***********************************************************************/
+
+static int unix_fds[MAX_UNIX_FDS];
+
+__attribute__ ((constructor)) static void udtrace_init(void) {
+	int i;
+	LOG("Unix Domain Socket Trace initialized\n");
+	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
+		unix_fds[i] = -1;
+	}
+}
+
+/* add a file descriptor from the list of to-be-traced ones */
+void add_fd(int fd)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
+		if (unix_fds[i] == -1) {
+			LOG("Adding FD %d\n", fd);
+			unix_fds[i] = fd;
+			return;
+		}
+	}
+	LOG("Couldn't add UNIX FD %d (no space in unix_fds)\n", fd);
+}
+
+/* delete a file descriptor from the list of to-be-traced ones */
+void del_fd(int fd)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
+		if (unix_fds[i] == fd) {
+			LOG("Removing FD %d\n", fd);
+			unix_fds[i] = -1;
+			return;
+		}
+	}
+	LOG("Couldn't delete UNIX FD %d (no such FD)\n", fd);
+}
+
+/* is the given file descriptor part of the to-be-traced unix domain fd's? */
+bool is_unix_socket(int fd)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(unix_fds); i++) {
+		if (unix_fds[i] == fd)
+			return true;
+	}
+	return false;
+}
+
+
+/* taken from libosmocore */
+static char hexd_buff[4096];
+static const char hex_chars[] = "0123456789abcdef";
+char *udtrace_hexdump(const unsigned char *buf, int len, char *delim)
+{
+	int i;
+	char *cur = hexd_buff;
+
+	hexd_buff[0] = 0;
+	for (i = 0; i < len; i++) {
+		const char *delimp = delim;
+		int len_remain = sizeof(hexd_buff) - (cur - hexd_buff);
+		if (len_remain < 3)
+			break;
+
+		*cur++ = hex_chars[buf[i] >> 4];
+		*cur++ = hex_chars[buf[i] & 0xf];
+
+		while (len_remain > 1 && *delimp) {
+			*cur++ = *delimp++;
+			len_remain--;
+		}
+
+		*cur = 0;
+	}
+	hexd_buff[sizeof(hexd_buff)-1] = 0;
+	return hexd_buff;
+}