initial commit

5 files changed, 180 insertions, 0 deletions

diff --git a/.gitignore b/.gitignore
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+++ b/.gitignore
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+*.o
+full_resolver
+.*.swp
diff --git a/Makefile b/Makefile
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+++ b/Makefile
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+# File: full_resolver/Makefile
+# License: CC-BY-SA 4.0
+# Author: bgstack15
+# Startdate: 2020-09-02
+# Title: Makefile for full_resolver
+# Purpose: compile the project
+# History:
+# Usage:
+#    make DEBUG=1
+# References:
+#    https://bgstack15.wordpress.com/2019/11/04/sample-makefile/
+# Improve:
+#    investigate why the .o build section is not used
+# Dependencies:
+# Documentation:
+#    includes nice DEBUG macro passing, which is not yet documented in reference 1 as of the document startdate.
+
+CC = gcc
+CFLAGS = -g -Wall -Wextra $(DEBUGFLAGS)
+
+LDFLAGS = -g -ludns
+ifneq (,$(DEBUG))
+	LDFLAGS+=-DDEBUG=1
+endif
+
+src = $(wildcard *.c)
+obj = $(src:.pp=.o)
+
+BUILD_DIR ?= .
+
+OUTEXE = full_resolver
+
+all: $(OUTEXE)
+
+# compile, which is not actually used?
+$(BUILDDIR)/%.o: %.c
+	$(CC) -c $(CFLAGS) $+
+
+# link
+$(OUTEXE): $(obj)
+	$(CC) -o $@ $^ $(LDFLAGS)
+
+.PHONY: clean cleanall list
+
+list:
+	@$(MAKE) -pRrq -f $(lastword $(MAKEFILE_LIST)) : 2>/dev/null | ${awkbin} -v RS= -F: '/^# File/,/^# Finished Make data base/ {if ($$1 !~ "^[#.]") {print $$1}}' | ${sortbin} | ${grepbin} -E -v -e '^[^[:alnum:]]' -e '^$@$$' -e '\.(cp*|o)'
+
+clean:
+	rm -f $(obj)
+
+cleanall:
+	rm -f $(obj) $(OUTEXE)
diff --git a/README.md b/README.md
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+++ b/README.md
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+# README for full_resolver
+## Overview
+Project `full_resolver` is part of a solution for blocking ads with dns null-routing. Specifically, this program is a troubleshooting tool for checking if a list of names are being blocked.
+
+## Using full_resolver
+Pass to standard input a list of domains, one per line. The program will resolve the domain names and display a custom output.
+This project was designed primarily for taking abbreviated output of a HAR file and turning it into IP addresses.
+
+    <input.har jq ".log.entries" | jq --raw-output "[.[] | .request.url] | sort | unique | .[]" | awk -F'/' '!x[$3]++ {print $3}' | ./full_resolver
+
+## Compiling full_resolver
+Use the provided Makefile.
+
+    make
+
+Accepted parameters include:
+1. DEBUG=1
+  This will set the C macro DEBUG so the debugging fprint instructions are included.
+
+## Dependencies
+[udns](http://www.corpit.ru/mjt/udns.html), found via [https://stackoverflow.com/questions/12328093/dns-lookup-in-c-c](https://stackoverflow.com/questions/12328093/dns-lookup-in-c-c)
+
+## References
+[1][file:///mnt/public/Support/Programs/dns/Troubleshooting-Adblocking-with-DNS.md]
+[2][] Web version of [reference 1][1]
diff --git a/full_resolver.c b/full_resolver.c
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index 0000000..9c885a2
--- /dev/null
+++ b/full_resolver.c
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+// File: full_resolver.c
+// License: CC-BY-SA 4.0
+// Author: bgstack15
+// Startdate: 2020-09-02 13:59
+// Title: Fully Resolve Domain Names from Stdin
+// Purpose: custom output for ipv4 dns lookups
+// History:
+// Usage:
+// References:
+//    https://stackoverflow.com/a/12252195/3569534
+// Improve:
+// Dependencies:
+//    devuan: libudns-dev
+// Documentation:
+//    /mnt/public/Support/Programs/dns/Troubleshooting-Adblocking-With-DNS.md
+#include <stdio.h>
+#include "/usr/include/udns.h"
+#include "full_resolver.h"
+
+int main(int argc, const char* argv[]) {
+	char *line = NULL;
+	size_t size;
+
+	struct dns_ctx *ctx;
+	dns_init(ctx,1);
+	#ifdef DEBUG
+	printf("BEGIN\n");
+	#endif
+	while (getline(&line, &size, stdin) != -1) {
+		full_resolve(line, ctx);
+	}
+//		printf("No line\n");
+   return 0;
+}
diff --git a/full_resolver.h b/full_resolver.h
new file mode 100644
index 0000000..ee5dbd1
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+++ b/full_resolver.h
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+// File: full_resolver.h
+// License: CC-BY-SA 4.0
+// Author: bgstack15
+// Startdate: 2020-09-02 13:59
+// Title: Header for full_resolver
+// Purpose: library for full_resolver
+// History:
+// Usage:
+// References:
+//    [1] https://stackoverflow.com/a/2693826/3569534
+//    [2] strtok safety https://stackoverflow.com/a/23961526/3569534
+//    [3] https://stackoverflow.com/questions/32845445/convert-ip-address-in-sockaddr-to-uint32-t/32845610#32845610
+//		[4] https://codegolf.stackexchange.com/questions/197879/convert-a-32-bit-binary-ipv4-address-to-its-quad-dotted-notation/197925#197925
+// Improve:
+// Dependencies:
+// Documentation:
+
+#ifndef FULL_RESOLVER_H
+#define FULL_RESOLVER_H 20200902
+#include <stdio.h>
+// If switch to getaddrinfo, need sys/types.h sys/socket.h netdb.h
+#include <string.h>
+#include <udns.h>
+#include <linux/in.h> // proper form is to use arpa/inet.h but it will fail the implicit declaration of function ntohl
+
+// Forward declarations
+u_int32_t ntohl(struct in_addr); // have to declare this to avoid warning
+
+int full_resolve(char*, struct dns_ctx* ctx);
+
+int conv_ipv4_dec_to_dotquad(long ip);
+
+// Functions
+int full_resolve(char* name, struct dns_ctx *ctx) {
+	strtok(name, "\n"); // strip newline
+	struct dns_rr_a4 *rr;
+   u_int32_t r;
+	//dns_resolve_dn(ctx, name, DNS_C_IN, DNS_T_A, 0, *dns_parse_a4);
+	rr = dns_resolve_a4(ctx, name, 0);
+	switch (dns_status(ctx)) {
+		case 0:
+			//printf("%d\n",rr->dnsa4_nrr);
+			for (int j=0; j < rr->dnsa4_nrr; ++j) {
+				r = ntohl(rr->dnsa4_addr[j]);
+				printf("%d: %s %s ",j,rr->dnsa4_qname,rr->dnsa4_cname);
+				conv_ipv4_dec_to_dotquad(r);
+				printf("\n");
+				//printf("%d \n",rr->dnsa4_addr[j]);
+			}
+			//printf("\n");
+			break;
+		default:
+			printf("%d: %s\n",dns_status(ctx),name);
+			break;
+	}
+	//printf("%s %s\n", prepend, name, ctx);
+	return 1;
+}
+
+int conv_ipv4_dec_to_dotquad(long ip) {
+// ripped from [4]
+	for(int i=4;i--;)
+		printf(".%hhu"+i/3,ip>>i*8);
+}
+
+#endif