add tool to enter vpn

.clang-format

@@ -0,0 +1,12 @@
+---
+AccessModifierOffset: 0
+IndentAccessModifiers: true
+AlignTrailingComments: true
+AllowShortFunctionsOnASingleLine: false
+AllowShortIfStatementsOnASingleLine: true
+AllowShortLoopsOnASingleLine: true
+BreakBeforeBinaryOperators: false
+IndentWidth: 4
+SortIncludes: false
+NamespaceIndentation: All
+...

Makefile

@@ -1,6 +1,6 @@
 CFLAGS = -std=gnu99 -pie -fPIC -pedantic -Wno-imports -Wunused -Wno-missing-field-initializers -Wextra -Wunreachable-code -O3
 
-all: wireguard_mount wireguard_resolve
+all: wireguard_mount wireguard_resolve enter_vpn
 
 wireguard_mount: src/wireguard-mount.c
 	mkdir -p bin
@@ -10,7 +10,16 @@ wireguard_resolve: src/resolve.c src/resolve.s
 	mkdir -p bin
 	gcc -shared -o bin/wireguard-resolve.so -nostdlib -fPIC src/resolve.c src/resolve.s
 
-install_mount: systemd bin:
+enter_vpn: src/enter_vpn.c
+	mkdir -p bin
+	gcc $(CFLAGS) -o bin/enter_vpn src/enter_vpn.c
+
+format: src scripts
+	clang-format -i src/*.c
+	ruff --fix scripts
+	black scripts
+
+install_mount: systemd bin
 	mkdir -p /snacks/wireguard/bin
 	cp bin/wireguard-mount /snacks/wireguard/bin/wireguard-mount
 	cp systemd/wireguard-mount.service /etc/systemd/system/wireguard-mount.service
@@ -28,3 +37,6 @@ install_basic: systemd scripts bin
 	cp scripts/inner_basic.sh /snacks/wireguard/scripts/inner_basic.sh
 	chmod -R 755 /snacks/wireguard
 	systemctl daemon-reload
+
+
+

scripts/connect.py

@@ -1,15 +1,20 @@
 #!/usr/bin/env python3
 import subprocess, os
+
 newenv = os.environ.copy()
 newenv["LD_PRELOAD"] = "/snacks/wireguard/bin/wireguard-resolve.so"
 
+
 def default_devices():
     with open("/proc/1/net/dev", "r") as f:
         return f.read()
+
+
 def vpn_devices():
     with open("/proc/self/net/dev", "r") as f:
         return f.read()
 
+
 def wireguard():
     try:
         os.mkdir("/run/netns")
@@ -39,17 +44,70 @@ def wireguard():
         subprocess.run(["ip", "link", "add", "name", "mynet0", "type", "bridge"])
 
     if "veth-inner" in default_devices():
-        subprocess.run(["nsenter", "--net=/proc/1/ns/net", "ip", "link", "del", "dev", "veth-inner"])
+        subprocess.run(
+            [
+                "nsenter",
+                "--net=/proc/1/ns/net",
+                "ip",
+                "link",
+                "del",
+                "dev",
+                "veth-inner",
+            ]
+        )
     if "veth-outer" in default_devices():
-        subprocess.run(["nsenter", "--net=/proc/1/ns/net", "ip", "link", "del", "dev", "veth-outer"])
+        subprocess.run(
+            [
+                "nsenter",
+                "--net=/proc/1/ns/net",
+                "ip",
+                "link",
+                "del",
+                "dev",
+                "veth-outer",
+            ]
+        )
     if "vpn" in default_devices():
-        subprocess.run(["nsenter", "--net=/proc/1/ns/net", "ip", "link", "del", "dev", "vpn"])
+        subprocess.run(
+            ["nsenter", "--net=/proc/1/ns/net", "ip", "link", "del", "dev", "vpn"]
+        )
 
     subprocess.run(["modprobe", "wireguard"])
-    subprocess.run(["nsenter", "--net=/proc/1/ns/net", "ip", "link", "add", "dev", "vpn", "type", "wireguard"])
+    subprocess.run(
-    subprocess.run(["nsenter", "--net=/proc/1/ns/net", "ip", "link", "set", "dev", "vpn", "netns", "vpn"])
+        [
-    subprocess.run(["nsenter", "--net=/run/vpn/net", "/snacks/wireguard/scripts/inner.sh"], env=newenv)
+            "nsenter",
-    subprocess.run(["nsenter", "--net=/proc/1/ns/net", "/snacks/wireguard/scripts/outer.sh"], env=newenv)
+            "--net=/proc/1/ns/net",
+            "ip",
+            "link",
+            "add",
+            "dev",
+            "vpn",
+            "type",
+            "wireguard",
+        ]
+    )
+    subprocess.run(
+        [
+            "nsenter",
+            "--net=/proc/1/ns/net",
+            "ip",
+            "link",
+            "set",
+            "dev",
+            "vpn",
+            "netns",
+            "vpn",
+        ]
+    )
+    subprocess.run(
+        ["nsenter", "--net=/run/vpn/net", "/snacks/wireguard/scripts/inner.sh"],
+        env=newenv,
+    )
+    subprocess.run(
+        ["nsenter", "--net=/proc/1/ns/net", "/snacks/wireguard/scripts/outer.sh"],
+        env=newenv,
+    )
+
 
 try:
     self_ns = os.readlink("/proc/self/ns/net")
@@ -61,4 +119,3 @@ else:
         wireguard()
     else:
         print("This script should be called from the VPN network namespace.")
-

scripts/connect_basic.py

@@ -1,15 +1,20 @@
 #!/usr/bin/env python3
 import subprocess, os
+
 newenv = os.environ.copy()
 newenv["LD_PRELOAD"] = "/snacks/wireguard/bin/wireguard-resolve.so"
 
+
 def default_devices():
     with open("/proc/1/net/dev", "r") as f:
         return f.read()
+
+
 def vpn_devices():
     with open("/proc/self/net/dev", "r") as f:
         return f.read()
 
+
 def wireguard():
     try:
         os.mkdir("/run/netns")
@@ -32,12 +37,42 @@ def wireguard():
     if "vpn" in vpn_devices():
         subprocess.run(["ip", "link", "del", "dev", "vpn"])
     if "vpn" in default_devices():
-        subprocess.run(["nsenter", "--net=/proc/1/ns/net", "ip", "link", "del", "dev", "vpn"])
+        subprocess.run(
+            ["nsenter", "--net=/proc/1/ns/net", "ip", "link", "del", "dev", "vpn"]
+        )
 
     subprocess.run(["modprobe", "wireguard"])
-    subprocess.run(["nsenter", "--net=/proc/1/ns/net", "ip", "link", "add", "dev", "vpn", "type", "wireguard"])
+    subprocess.run(
-    subprocess.run(["nsenter", "--net=/proc/1/ns/net", "ip", "link", "set", "dev", "vpn", "netns", "vpn"])
+        [
-    subprocess.run(["nsenter", "--net=/run/vpn/net", "/snacks/wireguard/scripts/inner_basic.sh"], env=newenv)
+            "nsenter",
+            "--net=/proc/1/ns/net",
+            "ip",
+            "link",
+            "add",
+            "dev",
+            "vpn",
+            "type",
+            "wireguard",
+        ]
+    )
+    subprocess.run(
+        [
+            "nsenter",
+            "--net=/proc/1/ns/net",
+            "ip",
+            "link",
+            "set",
+            "dev",
+            "vpn",
+            "netns",
+            "vpn",
+        ]
+    )
+    subprocess.run(
+        ["nsenter", "--net=/run/vpn/net", "/snacks/wireguard/scripts/inner_basic.sh"],
+        env=newenv,
+    )
+
 
 try:
     self_ns = os.readlink("/proc/self/ns/net")
@@ -49,4 +84,3 @@ else:
         wireguard()
     else:
         print("This script should be called from the VPN network namespace.")
-

src/enter_vpn.c

@@ -1,11 +1,11 @@
 #define _GNU_SOURCE
 
-#include <sched.h>
 #include <fcntl.h>
 #include <pwd.h>
+#include <sched.h>
 #include <stdio.h>
-#include <unistd.h>
 #include <string.h>
+#include <unistd.h>
 
 int main() {
     char shell[128] = {0};
@@ -30,7 +30,7 @@ int main() {
         perror("open /run/vpn/net");
         return 1;
     }
-    execl(shell, shell, NULL);
+    execl("csshell", "bshell", NULL);
     perror(NULL);
     return 0;
 }

src/wireguard-mount.c

@@ -1,7 +1,7 @@
-#include <sys/mount.h>
-#include <unistd.h>
 #include <stdio.h>
+#include <sys/mount.h>
 #include <systemd/sd-daemon.h>
+#include <unistd.h>
 
 int main() {
     char mount_path[32] = {0};