dns: add port overriding support

doc/config/common.md

@@ -203,6 +203,24 @@ Default: `0`
 
 Replace the HOST field in HTTP request headers with the settings above. This may help bypass network restrictions in some regions.
 
+### `startupPort`
+
+Default: `0` (i.e. no operation will perform)
+
+Overrides the port of connections to the `startup` server. The current implementation affects every TCP connection to the port 80.
+
+### `billingPort`
+
+Default: `0` (i.e. no operation will perform)
+
+Overrides the port of connections to the `billing` server. The current implementation affects every TCP connection to the port 8443.
+
+### `aimedbPort`
+
+Default: `0` (i.e. no operation will perform)
+
+Overrides the port of connections to the `aimedb` server. The current implementation affects every TCP connection to the port 22345.
+
 ## `[ds]`
 
 Controls emulation of the "DS (Dallas Semiconductor) EEPROM" chip on the AMEX

hooklib/dns.c

@@ -88,6 +88,11 @@ static DWORD WINAPI hook_send(
         int len,
         int flags);
 
+static int WINAPI hook_connect(
+        SOCKET s,
+        const struct sockaddr *name,
+        int namelen);
+
 /* Link pointers */
 
 static DNS_STATUS (WINAPI *next_DnsQuery_A)(
@@ -135,6 +140,11 @@ static DWORD (WINAPI *next_send)(
         int len,
         int flags);
 
+static int (__stdcall *next_connect)(
+        SOCKET s,
+        const struct sockaddr *name,
+        int namelen);
+
 static const struct hook_symbol dns_hook_syms_dnsapi[] = {
     {
         .name       = "DnsQuery_A",
@@ -180,11 +190,22 @@ static struct hook_symbol http_hook_syms_ws2[] = {
     },
 };
 
+static struct hook_symbol port_hook_syms_ws2[] = {
+    {
+        .name       = "connect",
+        .patch      = hook_connect,
+        .link       = (void **) &next_connect
+    },
+};
+
 static bool dns_hook_initted;
 static CRITICAL_SECTION dns_hook_lock;
 static struct dns_hook_entry *dns_hook_entries;
 static size_t dns_hook_nentries;
 static char received_title_url[255];
+static unsigned short startup_port;
+static unsigned short billing_port;
+static unsigned short aimedb_port;
 
 static void dns_hook_init(void)
 {
@@ -226,6 +247,21 @@ void http_hook_init(){
             _countof(http_hook_syms_ws2));
 }
 
+void port_hook_init(unsigned short _startup_port, unsigned short _billing_port, unsigned short _aimedb_port){
+    startup_port = _startup_port;
+    billing_port = _billing_port;
+    aimedb_port = _aimedb_port;
+    for (size_t i = 0; i < _countof(port_hook_syms_ws2); ++i) {
+        port_hook_syms_ws2[i].ordinal = get_function_ordinal("ws2_32.dll", port_hook_syms_ws2[i].name);
+    }
+
+    hook_table_apply(
+            NULL,
+            "ws2_32.dll",
+            port_hook_syms_ws2,
+            _countof(port_hook_syms_ws2));
+}
+
 // This function match domain and subdomains like *.naominet.jp.
 bool match_domain(const wchar_t* target, const wchar_t* pattern) {
     if (_wcsicmp(pattern, target) == 0) {
@@ -624,7 +660,7 @@ static bool WINAPI hook_WinHttpCrackUrl(
         if (match_domain(pwszUrl, pos->from)) {
             wchar_t* toAddr = pos->to;
             wchar_t titleBuffer[255];
-            
+
             if(wcscmp(toAddr, L"title") == 0) {
                 size_t wstr_c;
                 mbstowcs_s(&wstr_c, titleBuffer, 255, received_title_url, strlen(received_title_url));
@@ -651,6 +687,49 @@ static bool WINAPI hook_WinHttpCrackUrl(
     );
 }
 
+int WINAPI hook_connect(SOCKET s, const struct sockaddr *name, int namelen) {
+    const struct sockaddr_in *n;
+    struct sockaddr_in new_name;
+    unsigned ip;
+    unsigned short port, new_port;
+
+    EnterCriticalSection(&dns_hook_lock);
+
+    n = (const struct sockaddr_in *)name;
+    ip = n->sin_addr.S_un.S_addr;
+    if (WSANtohs(s, n->sin_port, &port)) return SOCKET_ERROR;
+
+    if (port == 80 && startup_port) {
+        new_port = startup_port;
+    } else if (port == 8443 && billing_port) {
+        new_port = billing_port;
+    } else if (port == 22345 && aimedb_port) {
+        new_port = aimedb_port;
+    } else { // No match
+        dprintf("TCP Connect: %u.%u.%u.%u:%hu\n", ip & 0xff, (ip >> 8) & 0xff, (ip >> 16) & 0xff, (ip >> 24) & 0xff, port);
+
+        LeaveCriticalSection(&dns_hook_lock);
+        return next_connect(
+            s,
+            name,
+            namelen
+        );
+    }
+
+    // matched
+    new_name = *n;
+    if (WSAHtons(s, new_port, &new_name.sin_port)) return SOCKET_ERROR;
+
+    dprintf("TCP Connect: %u.%u.%u.%u:%hu, mapped to port %hu\n", ip & 0xff, (ip >> 8) & 0xff, (ip >> 16) & 0xff, (ip >> 24) & 0xff, port, new_port);
+
+    LeaveCriticalSection(&dns_hook_lock);
+    return next_connect(
+        s,
+        (const struct sockaddr *)&new_name,
+        sizeof(new_name)
+    );
+}
+
 DWORD WINAPI hook_send(SOCKET s, const char* buf, int len, int flags) {
     if (strstr(buf, "HTTP/") != NULL) {
         char *new_buf = malloc(len + 1);

hooklib/dns.h

@@ -4,6 +4,7 @@
 
 #include <stddef.h>
 void http_hook_init();
+void port_hook_init(unsigned short _startup_port, unsigned short _billing_port, unsigned short _aimedb_port);
 // if to_src is NULL, all lookups for from_src will fail
 HRESULT dns_hook_push(const wchar_t *from_src, const wchar_t *to_src);
 

meson.build

@@ -34,6 +34,7 @@ if cc.get_id() != 'msvc'
         '-static-libgcc',
         # '-ggdb',  # Add debug information
         '-lcrypt32', # Bcrypt needed for prashook
+        '-lws2_32', # WSAHtons / WSANtohs needed for porthook
         # '-Wl,-s',  # Strip debug symbols
         language: 'c',
     )

platform/config.c

@@ -123,6 +123,10 @@ void dns_config_load(struct dns_config *cfg, const wchar_t *filename)
             filename);
 
     cfg->replaceHost = GetPrivateProfileIntW(L"dns", L"replaceHost", 0, filename);
+
+    cfg->startupPort = GetPrivateProfileIntW(L"dns", L"startupPort", 0, filename);
+    cfg->billingPort = GetPrivateProfileIntW(L"dns", L"billingPort", 0, filename);
+    cfg->aimedbPort = GetPrivateProfileIntW(L"dns", L"aimedbPort", 0, filename);
 }
 
 void hwmon_config_load(struct hwmon_config *cfg, const wchar_t *filename)

platform/dns.c

@@ -20,6 +20,10 @@ HRESULT dns_platform_hook_init(const struct dns_config *cfg)
         http_hook_init();
     }
 
+    if(cfg->startupPort || cfg->billingPort || cfg->aimedbPort){
+        port_hook_init(cfg->startupPort, cfg->billingPort, cfg->aimedbPort);
+    }
+
     hr = dns_hook_push(L"tenporouter.loc", cfg->router);
 
     if (FAILED(hr)) {
@@ -112,40 +116,40 @@ HRESULT dns_platform_hook_init(const struct dns_config *cfg)
     if (FAILED(hr)) {
         return hr;
     }
-    
+
     // WAHLAP PowerOn
     hr = dns_hook_push(L"at.sys-all.cn", cfg->startup);
 
     if (FAILED(hr)) {
         return hr;
     }
-    
+
     hr = dns_hook_push(L"at.sys-allnet.cn", cfg->startup);
 
     if (FAILED(hr)) {
         return hr;
     }
-    
+
     // WAHLAP WeChat AimeDB Server
     hr = dns_hook_push(L"ai.sys-all.cn", cfg->aimedb);
 
     if (FAILED(hr)) {
         return hr;
     }
-    
+
     hr = dns_hook_push(L"ai.sys-allnet.cn", cfg->aimedb);
 
     if (FAILED(hr)) {
         return hr;
     }
-    
+
     // WAHLAP Billing
     hr = dns_hook_push(L"bl.sys-all.cn", cfg->billing);
 
     if (FAILED(hr)) {
         return hr;
     }
-    
+
     hr = dns_hook_push(L"bl.sys-allnet.cn", cfg->billing);
 
     if (FAILED(hr)) {

platform/dns.h

@@ -13,6 +13,9 @@ struct dns_config {
     wchar_t aimedb[128];
     wchar_t title[128];
     bool replaceHost;
+    unsigned short startupPort;
+    unsigned short billingPort;
+    unsigned short aimedbPort;
 };
 
 HRESULT dns_platform_hook_init(const struct dns_config *cfg);