Add a simple unix controller

Signed-off-by: Adrien Gallouët <adrien@gallouet.fr>

Makefile.am

@@ -1,6 +1,6 @@
 ACLOCAL_AMFLAGS = -I m4 --install
 
-bin_PROGRAMS = glorytun
+bin_PROGRAMS = glorytun glorytunctl
 
 glorytun_CFLAGS = $(libsodium_CFLAGS)
 glorytun_LDADD = $(libsodium_LIBS)
@@ -9,6 +9,8 @@ glorytun_SOURCES = \
     src/common.c \
     src/ip.h \
     src/str.h \
+    src/ctl.c \
+    src/ctl.h \
     src/main.c \
     src/option.c \
     src/option.h \
@@ -19,6 +21,18 @@ glorytun_SOURCES = \
     mud/mud.h \
     mud/mud.c
 
+glorytunctl_CFLAGS =
+glorytunctl_LDADD =
+glorytunctl_SOURCES = \
+    src/common.h \
+    src/common.c \
+    src/str.h \
+    src/ctl.c \
+    src/ctl.h \
+    src/mainctl.c \
+    src/option.c \
+    src/option.h
+
 EXTRA_DIST = \
     LICENSE \
     README.md \

meson.build

@@ -12,21 +12,31 @@ conf_data.set('prefix', prefix)
 conf_data.set('bindir', bindir)
 
 add_global_arguments('-DPACKAGE_VERSION="'+meson.project_version()+'"', language : 'c')
+add_global_arguments('-DPACKAGE_NAME="'+meson.project_name()+'"', language : 'c')
 
-src = [
+executable('glorytun', install: true,
+  sources: [
     'src/common.c',
     'src/iface.c',
     'src/option.c',
     'src/tun.c',
+    'src/ctl.c',
     'mud/mud.c',
     'src/main.c'
-]
+  ],
-
+  dependencies: [
-deps = [
     dependency('libsodium', version : '>=1.0.4')
-]
+  ]
+)
 
-executable('glorytun', install: true, sources: src, dependencies: deps)
+executable('glorytunctl', install: true,
+  sources: [
+    'src/common.c',
+    'src/option.c',
+    'src/ctl.c',
+    'src/mainctl.c'
+  ]
+)
 
 systemd = dependency('systemd', required: false)
 

src/common.h

@@ -6,6 +6,14 @@
 #include <unistd.h>
 #include <errno.h>
 
+#ifndef PACKAGE_NAME
+#define PACKAGE_NAME "glorytun"
+#endif
+
+#ifndef PACKAGE_VERSION
+#define PACKAGE_VERSION "0.0.0"
+#endif
+
 #define COUNT(x)       (sizeof(x)/sizeof(x[0]))
 
 #define ALIGN_SIZE     (1<<4)

src/ctl.c

@@ -0,0 +1,79 @@
+#include "common.h"
+
+#include "ctl.h"
+#include "str.h"
+
+#include <stdio.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/un.h>
+
+int
+ctl_init(const char *dir, const char *file)
+{
+    if (str_empty(dir) || str_empty(file)) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    if (mkdir(dir, 0700) == -1 && errno != EEXIST) {
+        perror("mkdir");
+        return -1;
+    }
+
+    const char *strs[] = {dir, "/", file};
+    char *path = str_cat(strs, 3);
+
+    if (!path)
+        return -1;
+
+    int fd = socket(AF_UNIX, SOCK_DGRAM, 0);
+
+    if (fd == -1) {
+        int err = errno;
+        free(path);
+        errno = err;
+        return -1;
+    }
+
+    struct sockaddr_un sun = {
+        .sun_family = AF_UNIX,
+    };
+
+    str_cpy(sun.sun_path, path, sizeof(sun.sun_path) - 1);
+    free(path);
+    unlink(sun.sun_path);
+
+    if (bind(fd, (struct sockaddr *)&sun, sizeof(sun)) == -1) {
+        int err = errno;
+        close(fd);
+        errno = err;
+        return -1;
+    }
+
+    return fd;
+}
+
+int
+ctl_connect(int fd, const char *dir, const char *file)
+{
+    if (fd < 0 || str_empty(dir) || str_empty(file)) {
+        errno = EINVAL;
+        return -1;
+    }
+
+    const char *strs[] = {dir, "/", file};
+    char *path = str_cat(strs, 3);
+
+    if (!path)
+        return -1;
+
+    struct sockaddr_un sun = {
+        .sun_family = AF_UNIX,
+    };
+
+    str_cpy(sun.sun_path, path, sizeof(sun.sun_path) - 1);
+    free(path);
+
+    return connect(fd, (struct sockaddr *)&sun, sizeof(sun));
+}

src/ctl.h

@@ -0,0 +1,19 @@
+#pragma once
+
+enum ctl_type {
+    CTL_UNKNOWN,
+    CTL_PING,
+    CTL_PONG,
+};
+
+struct ctl_msg {
+    enum ctl_type type;
+    union {
+        struct {
+            enum ctl_type type;
+        } unknown;
+    };
+};
+
+int ctl_init    (const char *, const char *);
+int ctl_connect (int, const char *, const char *);

src/main.c

@@ -1,24 +1,17 @@
 #include "common.h"
 
-#include "db.h"
+#include "ctl.h"
+#include "iface.h"
 #include "ip.h"
 #include "option.h"
 #include "str.h"
 #include "tun.h"
-#include "iface.h"
 
 #include <fcntl.h>
-#include <inttypes.h>
+#include <netinet/in.h>
-#include <limits.h>
 #include <poll.h>
 #include <signal.h>
 #include <stdio.h>
-#include <sys/socket.h>
-#include <sys/time.h>
-#include <netinet/in.h>
-
-#include <arpa/inet.h>
-#include <netdb.h>
 
 #include "../mud/mud.h"
 
@@ -26,10 +19,6 @@
 #define O_CLOEXEC 0
 #endif
 
-#ifndef PACKAGE_VERSION
-#define PACKAGE_VERSION "unknown"
-#endif
-
 #define GT_MTU(X) ((X)-28)
 
 static struct {
@@ -79,6 +68,9 @@ fd_set_nonblock(int fd)
 {
     int ret;
 
+    if (fd == -1)
+        return;
+
     do {
         ret = fcntl(fd, F_GETFL, 0);
     } while (ret == -1 && errno == EINTR);
@@ -377,24 +369,31 @@ main(int argc, char **argv)
 
     gt_setup_mtu(mud, tun_name);
 
+    int ctl_fd = ctl_init("/run/" PACKAGE_NAME, tun_name);
+
+    if (ctl_fd == -1) {
+        perror("gt_setup_ctl");
+        return 1;
+    }
+
     int mud_fd = mud_get_fd(mud);
 
     fd_set_nonblock(tun_fd);
     fd_set_nonblock(mud_fd);
-
+    fd_set_nonblock(icmp_fd);
-    if (icmp_fd != -1)
+    fd_set_nonblock(ctl_fd);
-        fd_set_nonblock(icmp_fd);
 
     gt_log("running...\n");
 
     fd_set rfds;
     FD_ZERO(&rfds);
 
-    int last_fd = 1 + MAX(tun_fd, MAX(mud_fd, icmp_fd));
+    int last_fd = 1 + MAX(tun_fd, MAX(mud_fd, MAX(ctl_fd, icmp_fd)));
 
     while (!gt.quit) {
         FD_SET(tun_fd, &rfds);
         FD_SET(mud_fd, &rfds);
+        FD_SET(ctl_fd, &rfds);
 
         if (icmp_fd != -1)
             FD_SET(icmp_fd, &rfds);
@@ -407,11 +406,13 @@ main(int argc, char **argv)
         }
 
         if (icmp_fd != -1 && FD_ISSET(icmp_fd, &rfds)) {
+            struct ip_common ic;
             struct sockaddr_storage ss;
             socklen_t sl = sizeof(ss);
+
             ssize_t r = recvfrom(icmp_fd, gt.buf.data, gt.buf.size, 0,
                                  (struct sockaddr *)&ss, &sl);
-            struct ip_common ic;
+
             if (!ip_get_common(&ic, gt.buf.data, r)) {
                 int mtu = ip_get_mtu(&ic, gt.buf.data, r);
                 if (mtu > 0) {
@@ -421,6 +422,40 @@ main(int argc, char **argv)
             }
         }
 
+        if (FD_ISSET(ctl_fd, &rfds)) {
+            struct ctl_msg msg;
+            struct ctl_msg reply;
+
+            struct sockaddr_storage ss;
+            socklen_t sl = sizeof(ss);
+
+            ssize_t r = recvfrom(ctl_fd, &msg, sizeof(msg), 0,
+                                 (struct sockaddr *)&ss, &sl);
+
+            if (r == (ssize_t)sizeof(msg)) {
+                switch (msg.type) {
+                case CTL_PING:
+                    reply = (struct ctl_msg){
+                        .type = CTL_PONG,
+                    };
+                    break;
+                default:
+                    reply = (struct ctl_msg){
+                        .type = CTL_UNKNOWN,
+                        .unknown = {
+                            .type = msg.type,
+                        },
+                    };
+                    break;
+                }
+                if (sendto(ctl_fd, &reply, sizeof(reply), 0,
+                           (const struct sockaddr *)&ss, sl) == -1)
+                    perror("sendto(ctl)");
+            } else if (r == -1 && errno != EAGAIN) {
+                perror("recvfrom(ctl)");
+            }
+        }
+
         if (FD_ISSET(tun_fd, &rfds)) {
             size_t size = 0;
 

src/mainctl.c

@@ -0,0 +1,93 @@
+#include "common.h"
+
+#include "ctl.h"
+#include "option.h"
+#include "str.h"
+
+#include <stdio.h>
+#include <sys/socket.h>
+
+#ifndef PACKAGE_VERSION
+#define PACKAGE_VERSION "unknown"
+#endif
+
+static struct {
+    char *dev;
+    int version;
+} gt = {};
+
+static int
+gt_setup_option(int argc, char **argv)
+{
+    // clang-format off
+
+    struct option opts[] = {
+        { "dev",     &gt.dev, option_str    },
+        { "version", NULL,    option_option },
+        {  NULL                                               },
+    };
+
+    // clang-format on
+
+    if (option(opts, argc, argv))
+        return 1;
+
+    gt.version = option_is_set(opts, "version");
+
+    return 0;
+}
+
+int
+main(int argc, char **argv)
+{
+    if (gt_setup_option(argc, argv))
+        return 1;
+
+    if (gt.version) {
+        gt_print(PACKAGE_VERSION "\n");
+        return 0;
+    }
+
+    int ctl_fd = ctl_init("/run/" PACKAGE_NAME, "client");
+
+    if (ctl_fd == -1) {
+        perror("ctl_init");
+        return 1;
+    }
+
+    if (ctl_connect(ctl_fd, "/run/" PACKAGE_NAME, gt.dev) == -1) {
+        perror("ctl_connect");
+        return 1;
+    }
+
+    struct ctl_msg msg = {
+        .type = CTL_PING,
+    };
+
+    if (send(ctl_fd, &msg, sizeof(msg), 0) == -1) {
+        perror("send");
+        return 1;
+    }
+
+    struct ctl_msg reply;
+
+    if (recv(ctl_fd, &reply, sizeof(reply), 0) == -1) {
+        perror("recv");
+        return 1;
+    }
+
+    switch (reply.type) {
+    case CTL_PONG:
+        gt_print("PONG!\n");
+        break;
+    case CTL_UNKNOWN:
+        gt_print("Unknown command: %i\n", reply.unknown.type);
+        break;
+    default:
+        gt_print("Bad reply from server: %i\n", reply.type);
+    }
+
+    close(ctl_fd);
+
+    return 0;
+}