From 840049332933425e655c8a517a4beb2fe7150a66 Mon Sep 17 00:00:00 2001
From: king <wangbojing@0voice.com>
Date: Sat, 10 Aug 2024 12:24:02 +0000
Subject: [PATCH] add linux dlsym hook

---
 test_so/posix.c   | 79 +++++++++++++++++++++++++++++++++++++++++++++++
 test_so/test_so.c | 29 +++++++++++++++++
 zv2404fs.c        | 63 ++++++++++++++++++++++++++++++++++++-
 3 files changed, 170 insertions(+), 1 deletion(-)
 create mode 100755 test_so/posix.c
 create mode 100755 test_so/test_so.c

diff --git a/test_so/posix.c b/test_so/posix.c
new file mode 100755
index 0000000..fd900cc
--- /dev/null
+++ b/test_so/posix.c
@@ -0,0 +1,79 @@
+
+
+// hook --> 
+
+// open
+
+
+// write
+
+
+// read
+
+
+// close
+
+#define _GNU_SOURCE
+#include <dlfcn.h>
+
+
+#include <stdio.h>
+
+
+
+typedef int (*open_t)(const char *pathname, int flags);
+open_t  open_f = NULL;
+
+typedef ssize_t (*read_t)(int fd, void *buf, size_t count);
+read_t read_f = NULL;
+
+
+typedef ssize_t (*write_t)(int fd, const void *buf, size_t count);
+write_t write_f = NULL;
+
+typedef int (*close_t)(int fd);
+close_t close_f = NULL;
+
+
+int open(const char *pathname, int flags) {
+
+	if (open_f == NULL) {
+		open_f = dlsym(RTLD_NEXT, "open");
+	}
+
+	printf("open .. %s\n", pathname);
+
+	return open_f(pathname, flags);
+}
+
+ssize_t read(int fd, void *buf, size_t count) {
+
+	if (read_f == NULL) {
+		read_f = dlsym(RTLD_NEXT, "read");
+	}
+
+	printf("read ..\n");
+	return read_f(fd, buf, count);
+}
+
+ssize_t write(int fd, const void *buf, size_t count) {
+
+	if (write_f == NULL) {
+		write_f = dlsym(RTLD_NEXT, "write");
+	}
+
+	printf("write ..\n");
+	return write_f(fd, buf, count);
+}
+
+int close(int fd) {
+	if (close_f == NULL) {
+		close_f = dlsym(RTLD_NEXT, "close");
+	}
+
+	printf("close ..\n");
+	return close_f(fd);
+}
+
+
+
diff --git a/test_so/test_so.c b/test_so/test_so.c
new file mode 100755
index 0000000..35b7c5b
--- /dev/null
+++ b/test_so/test_so.c
@@ -0,0 +1,29 @@
+
+
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+// posix
+int main() {
+
+	int fd = open("a.txt", O_CREAT | O_RDWR);
+
+	char *buffer = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
+	
+	write(fd, buffer, strlen(buffer));
+
+	char rbuffer[128] = {0};
+	read(fd, buffer, 128);
+
+	printf("rbuffer: %s\n", buffer);
+
+	close(fd);
+}
+
+
+
+
diff --git a/zv2404fs.c b/zv2404fs.c
index 04b79dd..32fe20d 100755
--- a/zv2404fs.c
+++ b/zv2404fs.c
@@ -255,12 +255,73 @@ int main(int argc, char *argv[]) {
 }
 
 
+
+
 #else
 
+
+
+typedef int (*open_t)(const char *pathname, int flags);
+open_t  open_f = NULL;
+
+typedef ssize_t (*read_t)(int fd, void *buf, size_t count);
+read_t read_f = NULL;
+
+
+typedef ssize_t (*write_t)(int fd, const void *buf, size_t count);
+write_t write_f = NULL;
+
+typedef int (*close_t)(int fd);
+close_t close_f = NULL;
+
+
+int open(const char *pathname, int flags) {
+
+	if (open_f == NULL) {
+		open_f = dlsym(RTLD_NEXT, "open");
+	}
+
+	printf("open .. %s\n", pathname);
+
+	return open_f(pathname, flags);
+}
+
+ssize_t read(int fd, void *buf, size_t count) {
+
+	if (read_f == NULL) {
+		read_f = dlsym(RTLD_NEXT, "read");
+	}
+
+	printf("read ..\n");
+	return read_f(fd, buf, count);
+}
+
+ssize_t write(int fd, const void *buf, size_t count) {
+
+	if (write_f == NULL) {
+		write_f = dlsym(RTLD_NEXT, "write");
+	}
+
+	printf("write ..\n");
+	return write_f(fd, buf, count);
+}
+
+int close(int fd) {
+	if (close_f == NULL) {
+		close_f = dlsym(RTLD_NEXT, "close");
+	}
+
+	printf("close ..\n");
+	return close_f(fd);
+}
+
+
+
+
 // posix
 int main() {
 
-	int fd = open("a.txt", O_CREAT | O_READ);
+	int fd = open("a.txt", O_CREAT | O_RDWR);
 
 	char *buffer = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";