From 88d4cb81b5340028fb3c60de362f8ffa1e6508ae Mon Sep 17 00:00:00 2001
From: Mikhail Novosyolov <mikhailnov@nixtux.ru>
Date: Mon, 23 May 2022 20:58:36 +0300
Subject: [PATCH] Implement reading params in FCGI in C

+ fix verifying IP address if the first character is a bad one.
---
 webserver/doskast-trigger-connect.c | 41 +++++++++++++++++++++++++----
 1 file changed, 36 insertions(+), 5 deletions(-)

diff --git a/webserver/doskast-trigger-connect.c b/webserver/doskast-trigger-connect.c
index e52c1ce..69aba21 100644
--- a/webserver/doskast-trigger-connect.c
+++ b/webserver/doskast-trigger-connect.c
@@ -2,12 +2,16 @@
 #include <fcntl.h>
 #include <stdlib.h>
 #include <stdint.h>
+#include <stdio.h>
 #include <string.h>
 #include <unistd.h>
-#include <fcgios.h>
-#include <fcgi_stdio.h>
 #include <gnutls/gnutls.h>
 #include <gnutls/crypto.h>
+// https://abf.io/import/cgilib
+#include <cgi.h>
+// https://abf.io/import/fcgi
+#include <fcgios.h>
+#include <fcgi_stdio.h>
 
 // allow to redefine as gcc -D...
 #ifndef DIR
@@ -27,9 +31,21 @@ _verify_ip(char *ip){
 		if (!( (ip[i] == '.') || /* IPv4 dots */
 			   (ip[i] == ':') || /* IPv6 */
 			   (ip[i] == '/') || /* XXX Is it needed for IPv6? */
-			   (isalnum(ip[i]) > 0) /* Numbers (v4 and v6) and letters (v6) */
+			   (isalnum(ip[i]) != 0) /* Numbers (v4 and v6) and letters (v6) */
 		   )) {
-			rc = i;
+			rc = 1;
+			break;
+		}
+	}
+	return rc;
+}
+
+int
+_verify_geometry(char *value){
+	int rc = 0;
+	for (int i = 0; i < strlen(value); i++){
+		if (isdigit(value[i]) == 0) {
+			rc = 1;
 			break;
 		}
 	}
@@ -79,7 +95,14 @@ main(){
 		fprintf(stderr, "Cannot chdir and chroot into %s\n", DIR);
 		goto out;
 	}
+	s_cgi *cgi;
 	while(FCGI_Accept() >= 0) {
+		cgi = cgiInit();
+		if (cgi == NULL) {
+			fprintf(stderr, "%s\n", "Error initializaing CGI");
+			http_code = HTTP_ERROR;
+			goto fcgi_out;
+		}
 		char *ip = getenv("REMOTE_ADDR");
 		if (ip == NULL) {
 			fprintf(stderr, "%s\n", "Env REMOTE_ADDR is not set");
@@ -92,6 +115,8 @@ main(){
 			http_code = HTTP_BAD_REQUEST;
 			goto fcgi_out;
 		}
+		char *cgi_width = cgiGetValue(cgi, "width");
+		char *cgi_height = cgiGetValue(cgi, "height");
 		char *hex;
 		int max_try = 10;
 		for (int i = 1; i <= max_try; i++) {
@@ -115,15 +140,21 @@ main(){
 			http_code = HTTP_ERROR;
 			goto fcgi_out;
 		}
-		fprintf(d, "%s", ip);
+		fprintf(d, "ip=%s\n", ip);
+		if ( (cgi_width != NULL) && (_verify_geometry(cgi_width) == 0) )
+			fprintf(d, "width=%s\n", cgi_width);
+		if ( (cgi_height != NULL) && (_verify_geometry(cgi_height) == 0) )
+			fprintf(d, "height=%s\n", cgi_height);
 		rc = fclose(d);
 		if (rc != 0) {
 			fprintf(stderr, "Error closing file %s/%s\n", DIR, hex);
 			http_code = HTTP_ERROR;
 			goto fcgi_out;
 		}
+		fprintf(stderr, "Closed file %s/%s\n", DIR, hex);
 		http_code = HTTP_OK;
 fcgi_out:
+		cgiFree(cgi);
 		printf("Status: %d\n", http_code);
 		printf("Content-Type: text/plain; charset=utf-8\n");
 		if (http_code == HTTP_OK) {