Add parsing of dhcp-option PROXY_HTTP

This adds support for setting a HTTP proxy that should be used after
connecting to a VPN.

The syntax has been picked to have compatibility with OpenVPN3.
Otherwise I would have used HTTP-PROXY instead.

Since this option requires an additional argument compared to the
existing dhcp-option keywords, move checking the number of arguments
to the individual keywords.

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20210416110955.1162574-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg22129.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

3 files changed, 28 insertions, 9 deletions

diff --git a/src/openvpn/options.c b/src/openvpn/options.c
index ef854c7..7a1e2da 100644
--- a/src/openvpn/options.c
+++ b/src/openvpn/options.c
@@ -7435,22 +7435,22 @@ add_option(struct options *options,
     }
 #endif /* ifdef _WIN32 */
 #if defined(_WIN32) || defined(TARGET_ANDROID)
-    else if (streq(p[0], "dhcp-option") && p[1] && !p[3])
+    else if (streq(p[0], "dhcp-option") && p[1])
     {
         struct tuntap_options *o = &options->tuntap_options;
         VERIFY_PERMISSION(OPT_P_IPWIN32);
         bool ipv6dns = false;
 
         if ((streq(p[1], "DOMAIN") || streq(p[1], "ADAPTER_DOMAIN_SUFFIX"))
-            && p[2])
+            && p[2] && !p[3])
         {
             o->domain = p[2];
         }
-        else if (streq(p[1], "NBS") && p[2])
+        else if (streq(p[1], "NBS") && p[2] && !p[3])
         {
             o->netbios_scope = p[2];
         }
-        else if (streq(p[1], "NBT") && p[2])
+        else if (streq(p[1], "NBT") && p[2] && !p[3])
         {
             int t;
             t = atoi(p[2]);
@@ -7461,7 +7461,8 @@ add_option(struct options *options,
             }
             o->netbios_node_type = t;
         }
-        else if ((streq(p[1], "DNS") || streq(p[1], "DNS6")) && p[2] && (!strstr(p[2], ":") || ipv6_addr_safe(p[2])))
+        else if ((streq(p[1], "DNS") || streq(p[1], "DNS6")) && p[2] && !p[3]
+                && (!strstr(p[2], ":") || ipv6_addr_safe(p[2])))
         {
             if (strstr(p[2], ":"))
             {
@@ -7474,19 +7475,19 @@ add_option(struct options *options,
                 dhcp_option_address_parse("DNS", p[2], o->dns, &o->dns_len, msglevel);
             }
         }
-        else if (streq(p[1], "WINS") && p[2])
+        else if (streq(p[1], "WINS") && p[2] && !p[3])
         {
             dhcp_option_address_parse("WINS", p[2], o->wins, &o->wins_len, msglevel);
         }
-        else if (streq(p[1], "NTP") && p[2])
+        else if (streq(p[1], "NTP") && p[2] && !p[3])
         {
             dhcp_option_address_parse("NTP", p[2], o->ntp, &o->ntp_len, msglevel);
         }
-        else if (streq(p[1], "NBDD") && p[2])
+        else if (streq(p[1], "NBDD") && p[2] && !p[3])
         {
             dhcp_option_address_parse("NBDD", p[2], o->nbdd, &o->nbdd_len, msglevel);
         }
-        else if (streq(p[1], "DOMAIN-SEARCH") && p[2])
+        else if (streq(p[1], "DOMAIN-SEARCH") && p[2] && !p[3])
         {
             if (o->domain_search_list_len < N_SEARCH_LIST_LEN)
             {
@@ -7502,6 +7503,13 @@ add_option(struct options *options,
         {
             o->disable_nbt = 1;
         }
+#if defined(TARGET_ANDROID)
+        else if (streq(p[1], "PROXY_HTTP") && p[3] && !p[4])
+        {
+            o->http_proxy_port = atoi(p[3]);
+            o->http_proxy = p[2];
+        }
+#endif
         else
         {
             msg(msglevel, "--dhcp-option: unknown option type '%s' or missing or unknown parameter", p[1]);
diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 2385377..2c1b270 100644
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -1870,6 +1870,13 @@ open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tun
         management_android_control(management, "DNSDOMAIN", tt->options.domain);
     }
 
+    if (tt->options.http_proxy)
+    {
+        struct buffer buf = alloc_buf_gc(strlen(tt->options.http_proxy) + 20, &gc);
+        buf_printf(&buf, "%s %d", tt->options.http_proxy, tt->options.http_proxy_port);
+        management_android_control(management, "HTTPPROXY", BSTR(&buf));
+    }
+
     int android_method = managment_android_persisttun_action(management);
 
     /* Android 4.4 workaround */
diff --git a/src/openvpn/tun.h b/src/openvpn/tun.h
index 60ebfdc..abc3a71 100644
--- a/src/openvpn/tun.h
+++ b/src/openvpn/tun.h
@@ -128,6 +128,10 @@ struct tuntap_options {
 
     struct in6_addr dns6[N_DHCP_ADDR];
     int dns6_len;
+#if defined(TARGET_ANDROID)
+    const char *http_proxy;
+    int http_proxy_port;
+#endif
 };
 
 #elif defined(TARGET_LINUX)