From 5b6002ffa927ae9987d978126fa7cc30067ac1f2 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Wed, 22 Jul 2015 11:46:42 +0200
Subject: [PATCH] Split HTTP header parsing into a common function.

---
 httpinput.cpp | 31 +++++++------------------------
 parse.cpp     | 27 +++++++++++++++++++++++++++
 parse.h       |  6 ++++++
 3 files changed, 40 insertions(+), 24 deletions(-)

diff --git a/httpinput.cpp b/httpinput.cpp
index 043c07c..025fd45 100644
--- a/httpinput.cpp
+++ b/httpinput.cpp
@@ -222,31 +222,14 @@ bool HTTPInput::parse_response(const std::string &request)
 		return false;
 	}
 
-	multimap<string, string> parameters;
-	for (size_t i = 1; i < lines.size(); ++i) {
-		size_t split = lines[i].find(":");
-		if (split == string::npos) {
-			log(WARNING, "[%s] Ignoring malformed HTTP response line '%s'",
-			        url.c_str(), lines[i].c_str());
-			continue;
-		}
-
-		string key(lines[i].begin(), lines[i].begin() + split);
-
-		// Skip any spaces after the colon.
-		do {
-			++split;
-		} while (split < lines[i].size() && lines[i][split] == ' ');
+	multimap<string, string> parameters = extract_headers(lines, url);
 
-		string value(lines[i].begin() + split, lines[i].end());
-
-		// Remove “Content-encoding: metacube”.
-		// TODO: Make case-insensitive.
-		if (key == "Content-encoding" && value == "metacube") {
-			continue;
-		}
-
-		parameters.insert(make_pair(key, value));
+	// Remove “Content-encoding: metacube”.
+	// TODO: Make case-insensitive.
+	multimap<string, string>::iterator encoding_it =
+		parameters.find("Content-encoding");
+	if (encoding_it != parameters.end() && encoding_it->second == "metacube") {
+		parameters.erase(encoding_it);
 	}
 
 	// Change “Server: foo” to “Server: metacube/0.1 (reflecting: foo)”
diff --git a/parse.cpp b/parse.cpp
index c14b47f..c33543f 100644
--- a/parse.cpp
+++ b/parse.cpp
@@ -3,6 +3,7 @@
 #include <string>
 #include <vector>
 
+#include "log.h"
 #include "parse.h"
 
 using namespace std;
@@ -55,6 +56,32 @@ vector<string> split_lines(const string &str)
 	return ret;
 }
 
+multimap<string, string> extract_headers(const vector<string> &lines, const string &log_context)
+{
+	multimap<string, string> parameters;
+	for (size_t i = 1; i < lines.size(); ++i) {
+		size_t split = lines[i].find(":");
+		if (split == string::npos) {
+			log(WARNING, "[%s] Ignoring malformed HTTP response line '%s'",
+			        log_context.c_str(), lines[i].c_str());
+			continue;
+		}
+
+		string key(lines[i].begin(), lines[i].begin() + split);
+
+		// Skip any spaces after the colon.
+		do {
+			++split;
+		} while (split < lines[i].size() && lines[i][split] == ' ');
+
+		string value(lines[i].begin() + split, lines[i].end());
+
+		parameters.insert(make_pair(key, value));
+	}
+
+	return parameters;
+}
+
 #define MAX_REQUEST_SIZE 16384  /* 16 kB. */
 
 RequestParseStatus wait_for_double_newline(string *existing_data, const char *new_data, size_t new_data_size)
diff --git a/parse.h b/parse.h
index de26064..a56b1f4 100644
--- a/parse.h
+++ b/parse.h
@@ -4,6 +4,7 @@
 // Various routines that deal with parsing; both HTTP requests and more generic text.
 
 #include <stddef.h>
+#include <map>
 #include <string>
 #include <vector>
 
@@ -13,6 +14,11 @@ std::vector<std::string> split_tokens(const std::string &line);
 // Split a string on \n or \r\n, e.g. "foo\nbar\r\n\nbaz\r\n\r\n" -> {"foo", "bar", "baz"}.
 std::vector<std::string> split_lines(const std::string &str);
 
+// Extract HTTP headers from a request or response. Ignores the first line,
+// where the verb or the return code is.
+std::multimap<std::string, std::string> extract_headers(
+	const std::vector<std::string> &lines, const std::string &log_context);
+
 // Add the new data to an existing string, looking for \r\n\r\n
 // (typical of HTTP requests and/or responses). Will return one
 // of the given statuses.
-- 
2.39.2