fixes #2 Websocket transport

This is a rather large changeset -- it fundamentally adds websocket
transport, but as part of this changeset we added a generic framework
for both HTTP and websocket.  We also made some supporting changes to
the core, such as changing the way timeouts work for AIOs and adding
additional state keeping for AIOs, and adding a common framework for
deferred finalization (to avoid certain kinds of circular deadlocks
during resource cleanup).  We also invented a new initialization framework
so that we can avoid wiring in knowledge about them into the master
initialization framework.

The HTTP framework is not yet complete, but it is good enough for simple
static serving and building additional services on top of -- including
websocket.  We expect both websocket and HTTP support to evolve
considerably, and so these are not part of the public API yet.

Property support for the websocket transport (in particular address
properties) is still missing, as is support for TLS.

The websocket transport here is a bit more robust than the original
nanomsg implementation, as it supports multiple sockets listening at
the same port sharing the same HTTP server instance, discriminating
between them based on URI (and possibly the virtual host).

Websocket is enabled by default at present, and work to conditionalize
HTTP and websocket further (to minimize bloat) is still pending.

1 files changed, 78 insertions, 13 deletions

diff --git a/src/core/strs.c b/src/core/strs.c
index 6cee605b..a03c0bb5 100644
--- a/src/core/strs.c
+++ b/src/core/strs.c
@@ -8,6 +8,9 @@
 // found online at https://opensource.org/licenses/MIT.
 //
 
+#include <ctype.h>
+#include <stdarg.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -17,35 +20,28 @@
 // part of standard C99.  (C11 has added some things here, but we cannot
 // count on them.)
 
+// Note that we supply our own version of strdup and strfree unconditionally,
+// so that these can be freed with nni_free(strlen(s)+1) if desired.  (Likewise
+// a string buffer allocated with nni_alloc can be freed with nni_strfree
+// provided the length is correct.)
+
 char *
 nni_strdup(const char *src)
 {
-#ifdef NNG_HAVE_STRDUP
-#ifdef _WIN32
-	return (_strdup(src));
-#else
-	return (strdup(src));
-#endif
-#else
 	char * dst;
-	size_t len = strlen(src);
+	size_t len = strlen(src) + 1;
 
 	if ((dst = nni_alloc(len)) != NULL) {
 		memcpy(dst, src, len);
 	}
 	return (dst);
-#endif
 }
 
 void
 nni_strfree(char *s)
 {
 	if (s != NULL) {
-#ifdef NNG_HAVE_STRDUP
-		free(s);
-#else
 		nni_free(s, strlen(s) + 1);
-#endif
 	}
 }
 
@@ -114,3 +110,72 @@ nni_strnlen(const char *s, size_t len)
 	return (n);
 #endif
 }
+
+char *
+nni_strcasestr(const char *s1, const char *s2)
+{
+#ifdef NNG_HAVE_STRCASESTR
+	return (strcasestr(s1, s2));
+#else
+	const char *t1, *t2;
+	while (*s1) {
+		for (t1 = s1, t2 = s2; *t1 && *t2; t2++, t1++) {
+			if (tolower(*t1) != tolower(*t2)) {
+				break;
+			}
+		}
+		if (*t2 == 0) {
+			return ((char *) s1);
+		}
+		s1++;
+	}
+	return (NULL);
+#endif
+}
+
+int
+nni_strncasecmp(const char *s1, const char *s2, size_t n)
+{
+#ifdef NNG_HAVE_STRNCASECMP
+#ifdef _WIN32
+	return (_strnicmp(s1, s2, n));
+#else
+	return (strncasecmp(s1, s2, n));
+#endif
+#else
+	for (int i = 0; i < n; i++) {
+		uint8_t c1 = (uint8_t) tolower(*s1++);
+		uint8_t c2 = (uint8_t) tolower(*s2++);
+		if (c1 == c2) {
+			if (c1 == 0) {
+				return (0);
+			}
+			continue;
+		}
+		return (c1 < c2 ? -1 : 1);
+	}
+	return (0);
+#endif
+}
+
+int
+nni_asprintf(char **sp, const char *fmt, ...)
+{
+	va_list ap;
+	size_t  len;
+	char *  s;
+
+	va_start(ap, fmt);
+	len = vsnprintf(NULL, 0, fmt, ap);
+	va_end(ap);
+	len++;
+
+	if ((s = nni_alloc(len)) == NULL) {
+		return (NNG_ENOMEM);
+	}
+	va_start(ap, fmt);
+	(void) vsnprintf(s, len, fmt, ap);
+	va_end(ap);
+	*sp = s;
+	return (0);
+}
\ No newline at end of file