ip-up-vpn: Create proper states for pppd and racoon.

VPN no longer uses system properties to pass parameters.

Change-Id: I13e4339ababb08552c4276c675c21176774da66c

1 files changed, 125 insertions, 9 deletions

diff --git a/cmds/ip-up-vpn/ip-up-vpn.c b/cmds/ip-up-vpn/ip-up-vpn.c
index bbf6b14..e9ee95d 100644
--- a/cmds/ip-up-vpn/ip-up-vpn.c
+++ b/cmds/ip-up-vpn/ip-up-vpn.c
@@ -17,19 +17,135 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <errno.h>
 
-#include <cutils/properties.h>
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <linux/if.h>
+#include <linux/route.h>
 
+#define LOG_TAG "ip-up-vpn"
+#include <cutils/log.h>
+
+#define DIR "/data/misc/vpn/"
+
+static const char *env(const char *name) {
+    const char *value = getenv(name);
+    return value ? value : "";
+}
+
+static int set_address(struct sockaddr *sa, const char *address) {
+    sa->sa_family = AF_INET;
+    return inet_pton(AF_INET, address, &((struct sockaddr_in *)sa)->sin_addr);
+}
+
+/*
+ * The primary goal is to create a file with VPN parameters. Currently they
+ * are interface, addresses, routes, DNS servers, and search domains. Each
+ * parameter occupies one line in the file, and it can be an empty string or
+ * space-separated values. The order and the format must be consistent with
+ * com.android.server.connectivity.Vpn. Here is an example.
+ *
+ *   ppp0
+ *   192.168.1.100/24
+ *   0.0.0.0/0
+ *   192.168.1.1 192.168.1.2
+ *   example.org
+ *
+ * The secondary goal is to unify the outcome of VPN. The current baseline
+ * is to have an interface configured with the given address and netmask
+ * and maybe add a host route to protect the tunnel. PPP-based VPN already
+ * does this, but others might not. Routes, DNS servers, and search domains
+ * are handled by the framework since they can be overridden by the users.
+ */
 int main(int argc, char **argv)
 {
-    if (argc > 1 && strlen(argv[1]) > 0) {
-        char dns[PROPERTY_VALUE_MAX];
-        char *dns1 = getenv("DNS1");
-        char *dns2 = getenv("DNS2");
-
-        snprintf(dns, sizeof(dns), "%s %s", dns1 ? dns1 : "", dns2 ? dns2 : "");
-        property_set("vpn.dns", dns);
-        property_set("vpn.via", argv[1]);
+    FILE *state = fopen(DIR ".tmp", "wb");
+    if (!state) {
+        LOGE("Cannot create state: %s", strerror(errno));
+        return 1;
+    }
+
+    if (argc >= 6) {
+        /* Invoked by pppd. */
+        fprintf(state, "%s\n", argv[1]);
+        fprintf(state, "%s/32\n", argv[4]);
+        fprintf(state, "0.0.0.0/0\n");
+        fprintf(state, "%s %s\n", env("DNS1"), env("DNS2"));
+        fprintf(state, "\n");
+    } else if (argc == 2) {
+        /* Invoked by racoon. */
+        const char *interface = env("INTERFACE");
+        const char *address = env("INTERNAL_ADDR4");
+        const char *routes = env("SPLIT_INCLUDE_CIDR");
+
+        int s = socket(AF_INET, SOCK_DGRAM, 0);
+        struct rtentry rt;
+        struct ifreq ifr;
+
+        memset(&rt, 0, sizeof(rt));
+        memset(&ifr, 0, sizeof(ifr));
+
+        /* Remove the old host route. There could be more than one. */
+        rt.rt_flags |= RTF_UP | RTF_HOST;
+        if (set_address(&rt.rt_dst, env("REMOTE_ADDR"))) {
+            while (!ioctl(s, SIOCDELRT, &rt));
+        }
+        if (errno != ESRCH) {
+            LOGE("Cannot remove host route: %s", strerror(errno));
+            return 1;
+        }
+
+        /* Create a new host route. */
+        rt.rt_flags |= RTF_GATEWAY;
+        if (!set_address(&rt.rt_gateway, argv[1]) ||
+                (ioctl(s, SIOCADDRT, &rt) && errno != EEXIST)) {
+            LOGE("Cannot create host route: %s", strerror(errno));
+            return 1;
+        }
+
+        /* Bring up the interface. */
+        ifr.ifr_flags = IFF_UP;
+        strncpy(ifr.ifr_name, interface, IFNAMSIZ);
+        if (ioctl(s, SIOCSIFFLAGS, &ifr)) {
+            LOGE("Cannot bring up %s: %s", interface, strerror(errno));
+            return 1;
+        }
+
+        /* Set the address. */
+        if (!set_address(&ifr.ifr_addr, address) ||
+                ioctl(s, SIOCSIFADDR, &ifr)) {
+            LOGE("Cannot set address: %s", strerror(errno));
+            return 1;
+        }
+
+        /* Set the netmask. */
+        if (!set_address(&ifr.ifr_netmask, env("INTERNAL_NETMASK4")) ||
+                ioctl(s, SIOCSIFNETMASK, &ifr)) {
+            LOGE("Cannot set netmask: %s", strerror(errno));
+            return 1;
+        }
+
+        /* TODO: Send few packets to trigger phase 2? */
+
+        fprintf(state, "%s\n", interface);
+        fprintf(state, "%s/%s\n", address, env("INTERNAL_CIDR4"));
+        fprintf(state, "%s\n", routes[0] ? routes : "0.0.0.0/0");
+        fprintf(state, "%s\n", env("INTERNAL_DNS4_LIST"));
+        fprintf(state, "%s\n", env("DEFAULT_DOMAIN"));
+    } else {
+        LOGE("Cannot parse parameters");
+        return 1;
+    }
+
+    fclose(state);
+    if (chmod(DIR ".tmp", 0444) || rename(DIR ".tmp", DIR "state")) {
+        LOGE("Cannot write state: %s", strerror(errno));
+        return 1;
     }
     return 0;
 }