1 files changed, 95 insertions, 0 deletions
diff --git a/src/detection/publicip/publicip.c b/src/detection/publicip/publicip.c
new file mode 100644
index 0000000..abca57c
--- /dev/null
+++ b/src/detection/publicip/publicip.c
@@ -0,0 +1,95 @@
+#include "publicip.h"
+#include "common/networking.h"
+
+#define FF_UNINITIALIZED ((const char*) (uintptr_t) -1)
+static FFNetworkingState states[2];
+static const char* statuses[2] = { FF_UNINITIALIZED, FF_UNINITIALIZED };
+
+void ffPreparePublicIp(FFPublicIPOptions* options) {
+    FFNetworkingState* state = &states[options->ipv6];
+    const char** status = &statuses[options->ipv6];
+    if (*status != FF_UNINITIALIZED) {
+        fputs("Error: PublicIp module can only be used once due to internal limitations\n", stderr);
+        exit(1);
+    }
+
+    state->timeout = options->timeout;
+    state->ipv6 = options->ipv6;
+
+    if (options->url.length == 0) {
+        state->compression = true;
+        state->tfo = true;
+        *status = ffNetworkingSendHttpRequest(state, options->ipv6 ? "v6.ipinfo.io" : "ipinfo.io", "/json", NULL);
+    } else {
+        FF_STRBUF_AUTO_DESTROY host = ffStrbufCreateCopy(&options->url);
+        uint32_t hostStartIndex = ffStrbufFirstIndexS(&host, "://");
+        if (hostStartIndex < host.length) {
+            if (hostStartIndex != 4 || !ffStrbufStartsWithIgnCaseS(&host, "http")) {
+                fputs("Error: only http: protocol is supported. Use `Command` module with `curl` if needed\n", stderr);
+                exit(1);
+            }
+            ffStrbufSubstrAfter(&host, hostStartIndex + (uint32_t) (strlen("://") - 1));
+        }
+        uint32_t pathStartIndex = ffStrbufFirstIndexC(&host, '/');
+
+        FF_STRBUF_AUTO_DESTROY path = ffStrbufCreate();
+        if (pathStartIndex != host.length) {
+            ffStrbufAppendNS(&path, pathStartIndex, host.chars + (host.length - pathStartIndex));
+            host.length = pathStartIndex;
+            host.chars[pathStartIndex] = '\0';
+        }
+
+        *status = ffNetworkingSendHttpRequest(state, host.chars, path.length == 0 ? "/" : path.chars, NULL);
+    }
+}
+
+static inline void wrapYyjsonFree(yyjson_doc** doc) {
+    assert(doc);
+    if (*doc) {
+        yyjson_doc_free(*doc);
+    }
+}
+
+const char* ffDetectPublicIp(FFPublicIPOptions* options, FFPublicIpResult* result) {
+    FFNetworkingState* state = &states[options->ipv6];
+    const char** status = &statuses[options->ipv6];
+    if (*status == FF_UNINITIALIZED) {
+        ffPreparePublicIp(options);
+    }
+
+    if (*status != NULL) {
+        return *status;
+    }
+
+    FF_STRBUF_AUTO_DESTROY response = ffStrbufCreateA(4096);
+    const char* error = ffNetworkingRecvHttpResponse(state, &response);
+
+    *state = (FFNetworkingState) {};
+    *status = FF_UNINITIALIZED;
+
+    if (error == NULL) {
+        ffStrbufSubstrAfterFirstS(&response, "\r\n\r\n");
+    } else {
+        return error;
+    }
+
+    if (response.length == 0) {
+        return "Empty server response received";
+    }
+
+    if (options->url.length == 0) {
+        yyjson_doc* FF_A_CLEANUP(wrapYyjsonFree) doc = yyjson_read_opts(response.chars, response.length, 0, NULL, NULL);
+        if (doc) {
+            yyjson_val* root = yyjson_doc_get_root(doc);
+            ffStrbufAppendJsonVal(&result->ip, yyjson_obj_get(root, "ip"));
+            ffStrbufDestroy(&result->location);
+            ffStrbufInitF(&result->location, "%s, %s", yyjson_get_str(yyjson_obj_get(root, "city")), yyjson_get_str(yyjson_obj_get(root, "country")));
+            return NULL;
+        }
+    }
+
+    ffStrbufDestroy(&result->ip);
+    ffStrbufInitMove(&result->ip, &response);
+    ffStrbufTrimRightSpace(&result->ip);
+    return NULL;
+}