rfc822: Retrieve header fields by name

[ccan] / ccan / rfc822 / rfc822.c

diff --git a/ccan/rfc822/rfc822.c b/ccan/rfc822/rfc822.c
index 6a0f95fc5f31ed7d9246c21719328b9641823774..f5ffd958e767c10ee9602059fac13fa1e8c59bde 100644 (file)
--- a/ccan/rfc822/rfc822.c
+++ b/ccan/rfc822/rfc822.c
@@ -350,3 +350,49 @@ struct bytestring rfc822_header_unfolded_value(struct rfc822_msg *msg,
 
        return hdr->unfolded;
 }
+
+/* Specifically locale *un*aware tolower() - headers should be ascii
+ * only, and if they're not best to leave them as is */
+static char xtolower(char c)
+{
+       if ((c >= 'A') && (c <= 'Z'))
+               return 'a' + (c - 'A');
+       else
+               return c;
+}
+
+static bool hdr_name_eq(struct bytestring a, struct bytestring b)
+{
+       int i;
+
+       if (a.len != b.len)
+               return false;
+
+       for (i = 0; i < a.len; i++)
+               if (xtolower(a.ptr[i]) != xtolower(b.ptr[i]))
+                       return false;
+
+       return true;
+}
+
+bool rfc822_header_is(struct rfc822_msg *msg, struct rfc822_header *hdr,
+                     const char *name)
+{
+       struct bytestring hname = rfc822_header_raw_name(msg, hdr);
+
+       if (!hname.ptr || !name)
+               return false;
+
+       return hdr_name_eq(hname, bytestring_from_string(name));
+}
+
+struct rfc822_header *rfc822_next_header_of_name(struct rfc822_msg *msg,
+                                                struct rfc822_header *hdr,
+                                                const char *name)
+{
+       do {
+               hdr = rfc822_next_header(msg, hdr);
+       } while (hdr && !rfc822_header_is(msg, hdr, name));
+
+       return hdr;
+}