From 35b88e235d2a2271f533d2a9b9b197bd187ada82 Mon Sep 17 00:00:00 2001
From: Nick Krichevsky <nick@ollien.com>
Date: Sat, 1 Sep 2018 20:00:53 -0400
Subject: [PATCH] Implement case_insensitive_strcmp

---
 common/http_types.c | 44 ++++++++++++++++++++++++++++++++------------
 common/http_types.h |  3 ++-
 2 files changed, 34 insertions(+), 13 deletions(-)

diff --git a/common/http_types.c b/common/http_types.c
index 0da4ae1..ab52837 100644
--- a/common/http_types.c
+++ b/common/http_types.c
@@ -52,22 +52,42 @@ void free_headers(struct http_header *headers) {
     free(headers);
 }
 
+static char *str_lower(const char *s) {
+    int length = strlen(s) + 1;
+    char *lower = malloc(length * sizeof(char));
+    char *lower_cursor = lower;
+    for (const char *cursor = s; *cursor != '\0'; (cursor++, lower_cursor++)) {
+        *lower_cursor = tolower(*cursor);
+    }
+
+    return lower;
+}
+
+/**
+ * Performs strcmp on lowercase versions of a and b
+ *
+ * @param a A null terminated string.
+ * @param b A null terminated string.
+ *
+ * @return strcmp(lower_a, lower_b)
+ */
+int case_insensitive_strcmp(const char *a, const char *b) {
+    char *a_lower = str_lower(a);
+    char *b_lower = str_lower(b);
+    int cmp = strcmp(a, b);
+    free(a_lower);
+    free(b_lower);
+
+    return cmp;
+}
+
 /**
  * Compare the name of a header to a given name, case insensitively
  *
  * @param name The name to compare against.
  *
- * @return The result of strcmp(lower_case_header_name, name)
+ * @return The result of strcmp(lower_case_header_name, actual_header_name)
  */
-int headercmp(const char *name) {
-    int name_length = strlen(name) + 1;
-    char *lower_name = malloc(name_length * sizeof(char));
-    char *lower_cursor = lower_name;
-    for (const char *cursor = name; *cursor != '\0'; (cursor++, lower_cursor++)) {
-        *lower_cursor = tolower(*cursor);
-    }
-    int cmp_result = strcmp(lower_name, name);
-    free(lower_name);
-
-    return cmp_result;
+int headercmp(struct http_header *header, const char *name) {
+    return case_insensitive_strcmp(header->name, name);
 }
diff --git a/common/http_types.h b/common/http_types.h
index 78344b8..05d1313 100644
--- a/common/http_types.h
+++ b/common/http_types.h
@@ -18,6 +18,7 @@ struct http_header {
 
 struct http_header *insert_header(const char *header_name, const char *header_value, struct http_header *existing_header);
 void free_headers(struct http_header *headers);
-int headercmp(const char *name);
+int case_insensitive_strcmp(const char *a, const char *b);
+int headercmp(struct http_header *header, const char *name);
 
 #endif