http: use nng_err throughout

6 files changed, 203 insertions, 219 deletions

diff --git a/src/supplemental/http/http_api.h b/src/supplemental/http/http_api.h
index 846d1c19..61c6e45f 100644
--- a/src/supplemental/http/http_api.h
+++ b/src/supplemental/http/http_api.h
@@ -34,20 +34,20 @@ typedef struct nng_http_chunks  nni_http_chunks;
 // These functions are private to the internal framework, and really should
 // not be used elsewhere.
 
-extern void nni_http_req_init(nni_http_req *);
-extern void nni_http_req_reset(nni_http_req *);
-extern int  nni_http_req_parse(nng_http *, void *, size_t, size_t *);
+extern void    nni_http_req_init(nni_http_req *);
+extern void    nni_http_req_reset(nni_http_req *);
+extern nng_err nni_http_req_parse(nng_http *, void *, size_t, size_t *);
 
-extern void nni_http_res_init(nni_http_res *);
-extern void nni_http_res_reset(nni_http_res *);
-extern int  nni_http_res_parse(nng_http *, void *, size_t, size_t *);
+extern void    nni_http_res_init(nni_http_res *);
+extern void    nni_http_res_reset(nni_http_res *);
+extern nng_err nni_http_res_parse(nng_http *, void *, size_t, size_t *);
 
 // Chunked transfer encoding.  For the moment this is not part of our public
 // API.  We can change that later.
 
 // nni_http_chunk_list_init creates a list of chunks, which shall not exceed
 // the specified overall size.  (Size 0 means no limit.)
-extern int nni_http_chunks_init(nni_http_chunks **, size_t);
+extern nng_err nni_http_chunks_init(nni_http_chunks **, size_t);
 
 extern void nni_http_chunks_free(nni_http_chunks *);
 
@@ -64,7 +64,8 @@ extern size_t nni_http_chunk_size(nni_http_chunk *);
 // nni_http_chunk_data returns a pointer to the data.
 extern void *nni_http_chunk_data(nni_http_chunk *);
 
-extern int nni_http_chunks_parse(nni_http_chunks *, void *, size_t, size_t *);
+extern nng_err nni_http_chunks_parse(
+    nni_http_chunks *, void *, size_t, size_t *);
 
 extern void nni_http_read_chunks(
     nni_http_conn *, nni_http_chunks *, nni_aio *);
@@ -93,7 +94,7 @@ extern void *nni_http_conn_get_ctx(nni_http_conn *);
 // These initialization functions create stream for HTTP transactions.
 // They should only be used by the server or client HTTP implementations,
 // and are not for use by other code.
-extern int nni_http_conn_init(nng_http **, nng_stream *, bool);
+extern nng_err nni_http_init(nng_http **, nng_stream *, bool);
 
 extern void nni_http_conn_close(nng_http *);
 extern void nni_http_conn_fini(nni_http_conn *);
@@ -105,19 +106,14 @@ extern int  nni_http_conn_getopt(
 // Note that the iovs of the aio's are clobbered by these methods -- callers
 // must not use them for any other purpose.
 
-extern int  nni_http_req_alloc(nni_http_req **, const nng_url *);
-extern int  nni_http_res_set_error(nni_http_res *, nng_http_status);
-extern void nni_http_req_free(nni_http_req *);
-extern void nni_http_res_free(nni_http_res *);
 extern void nni_http_write_req(nni_http_conn *, nni_aio *);
 extern void nni_http_read_res(nni_http_conn *, nni_aio *);
 extern void nni_http_read_req(nni_http_conn *, nni_aio *);
 extern void nni_http_write_res(nni_http_conn *, nni_aio *);
 extern void nni_http_read_discard(nni_http_conn *, size_t, nni_aio *);
 
-extern int nni_http_req_add_header(nni_http_req *, const char *, const char *);
-extern int nni_http_req_alloc_data(nni_http_req *, size_t);
-extern int nni_http_res_alloc_data(nni_http_res *, size_t);
+extern nng_err nni_http_req_alloc_data(nni_http_req *, size_t);
+extern nng_err nni_http_res_alloc_data(nni_http_res *, size_t);
 
 extern bool nni_http_is_error(nng_http *);
 
@@ -126,14 +122,14 @@ extern void nni_http_read_full(nni_http_conn *, nni_aio *);
 extern void nni_http_write(nni_http_conn *, nni_aio *);
 extern void nni_http_write_full(nni_http_conn *, nni_aio *);
 
-extern int         nni_http_add_header(nng_http *, const char *, const char *);
-extern int         nni_http_set_header(nng_http *, const char *, const char *);
+extern nng_err     nni_http_add_header(nng_http *, const char *, const char *);
+extern nng_err     nni_http_set_header(nng_http *, const char *, const char *);
 extern void        nni_http_del_header(nng_http *, const char *);
 extern const char *nni_http_get_header(nng_http *, const char *);
 
-extern void nni_http_get_body(nng_http *, void **, size_t *);
-extern void nni_http_set_body(nng_http *, void *, size_t);
-extern int  nni_http_copy_body(nng_http *, const void *, size_t);
+extern void    nni_http_get_body(nng_http *, void **, size_t *);
+extern void    nni_http_set_body(nng_http *, void *, size_t);
+extern nng_err nni_http_copy_body(nng_http *, const void *, size_t);
 
 // prune body clears the outgoing body (0 bytes), but leaves content-length
 // intact if present for the benefit of HEAD.
@@ -147,7 +143,7 @@ extern void nni_http_prune_body(nng_http *);
 // a restricted binding is required, we recommend using a URL consisting
 // of an empty host name, such as http://  or https://  -- this would
 // convert to binding to the default port on all interfaces on the host.
-extern int nni_http_server_init(nni_http_server **, const nng_url *);
+extern nng_err nni_http_server_init(nni_http_server **, const nng_url *);
 
 // nni_http_server_fini drops the reference count on the server, and
 // if this was the last reference, closes down the server and frees
@@ -158,13 +154,15 @@ extern void nni_http_server_fini(nni_http_server *);
 // This function will return NNG_EADDRINUSE if a conflicting handler
 // is already registered (i.e. a handler with the same value for Host,
 // Method, and URL.)
-extern int nni_http_server_add_handler(nni_http_server *, nni_http_handler *);
+extern nng_err nni_http_server_add_handler(
+    nni_http_server *, nni_http_handler *);
 
 // nni_http_del_handler removes the given handler.  The caller is
 // responsible for finalizing it afterwards.  If the handler was not found
 // (not registered), NNG_ENOENT is returned.  In this case it is unsafe
 // to make assumptions about the validity of the handler.
-extern int nni_http_server_del_handler(nni_http_server *, nni_http_handler *);
+extern nng_err nni_http_server_del_handler(
+    nni_http_server *, nni_http_handler *);
 
 // nni_http_server_set_tls adds a TLS configuration to the server,
 // and enables the use of it.  This returns NNG_EBUSY if the server is
@@ -172,12 +170,13 @@ extern int nni_http_server_del_handler(nni_http_server *, nni_http_handler *);
 // server client, so the caller must have configured it reasonably.
 // This API is not recommended unless the caller needs complete control
 // over the TLS configuration.
-extern int nni_http_server_set_tls(nni_http_server *, struct nng_tls_config *);
+extern nng_err nni_http_server_set_tls(
+    nni_http_server *, struct nng_tls_config *);
 
 // nni_http_server_get_tls obtains the TLS configuration if one is present,
 // or returns NNG_EINVAL.  The TLS configuration is invalidated if the
 // nni_http_server_set_tls function is called, so be careful.
-extern int nni_http_server_get_tls(
+extern nng_err nni_http_server_get_tls(
     nni_http_server *, struct nng_tls_config **);
 
 extern int nni_http_server_set(
@@ -186,7 +185,7 @@ extern int nni_http_server_get(
     nni_http_server *, const char *, void *, size_t *, nni_type);
 
 // nni_http_server_start starts listening on the supplied port.
-extern int nni_http_server_start(nni_http_server *);
+extern nng_err nni_http_server_start(nni_http_server *);
 
 // nni_http_server_stop stops the server, closing the listening socket.
 // Connections that have been "upgraded" are unaffected.  Connections
@@ -201,13 +200,13 @@ extern void nni_http_server_stop(nni_http_server *);
 extern void nni_http_server_close(nni_http_server *);
 
 // nni_http_server_set_error_page sets an error page for the named status.
-extern int nni_http_server_set_error_page(
+extern nng_err nni_http_server_set_error_page(
     nni_http_server *, nng_http_status, const char *);
 
 // nni_http_server_res_error takes replaces the body of the res with
 // a custom error page previously set for the server, using the status
 // of the res.  The res must have the status set first.
-extern int nni_http_server_error(nni_http_server *, nng_http *);
+extern nng_err nni_http_server_error(nni_http_server *, nng_http *);
 
 // nni_http_hijack is intended to be called by a handler that wishes to
 // take over the processing of the HTTP session -- usually to change protocols
@@ -219,7 +218,7 @@ extern int nni_http_server_error(nni_http_server *, nng_http *);
 // when a session is hijacked, the caller is also responsible for disposing
 // of the request structure.  (Some hijackers may keep the request for
 // further processing.)
-extern int nni_http_hijack(nni_http_conn *);
+extern nng_err nni_http_hijack(nni_http_conn *);
 
 // nni_http_handler_init creates a server handler object, for the supplied
 // URI (path only) with the callback.
@@ -227,17 +226,17 @@ extern int nni_http_hijack(nni_http_conn *);
 // Note that methods which modify a handler cannot be called while the handler
 // is registered with the server, and that a handler can only be registered
 // once per server.
-extern int nni_http_handler_init(
+extern nng_err nni_http_handler_init(
     nni_http_handler **, const char *, nng_http_handler_func);
 
 // nni_http_handler_init_file creates a handler with a function to serve
 // up a file named in the last argument.
-extern int nni_http_handler_init_file(
+extern nng_err nni_http_handler_init_file(
     nni_http_handler **, const char *, const char *);
 
 // nni_http_handler_init_file_ctype is like nni_http_handler_init_file, but
 // provides for setting the Content-Type explicitly (last argument).
-extern int nni_http_handler_init_file_ctype(
+extern nng_err nni_http_handler_init_file_ctype(
     nni_http_handler **, const char *, const char *, const char *);
 
 // nni_http_handler_init_directory arranges to serve up an entire
@@ -245,16 +244,16 @@ extern int nni_http_handler_init_file_ctype(
 // content type list.  Actual directories are required to contain a
 // file called index.html or index.htm.  We do not generate directory
 // listings for security reasons.
-extern int nni_http_handler_init_directory(
+extern nng_err nni_http_handler_init_directory(
     nni_http_handler **, const char *, const char *);
 
 // nni_http_handler_init_static creates a handler that serves up static content
 // supplied, with the Content-Type supplied in the final argument.
-extern int nni_http_handler_init_static(
+extern nng_err nni_http_handler_init_static(
     nni_http_handler **, const char *, const void *, size_t, const char *);
 
 // nni_http_handler_init_redirect creates a handler that redirects the request.
-extern int nni_http_handler_init_redirect(
+extern nng_err nni_http_handler_init_redirect(
     nni_http_handler **, const char *, nng_http_status, const char *);
 
 // nni_http_handler_fini destroys a handler.  This should only be done before
@@ -304,19 +303,20 @@ extern const char *nni_http_handler_get_uri(nni_http_handler *);
 
 // Client stuff.
 
-extern int  nni_http_client_init(nni_http_client **, const nng_url *);
-extern void nni_http_client_fini(nni_http_client *);
+extern nng_err nni_http_client_init(nni_http_client **, const nng_url *);
+extern void    nni_http_client_fini(nni_http_client *);
 
 // nni_http_client_set_tls sets the TLS configuration.  This wipes out
 // the entire TLS configuration on the client, so the caller must have
 // configured it reasonably.  This API is not recommended unless the
 // caller needs complete control over the TLS configuration.
-extern int nni_http_client_set_tls(nni_http_client *, struct nng_tls_config *);
+extern nng_err nni_http_client_set_tls(
+    nni_http_client *, struct nng_tls_config *);
 
 // nni_http_client_get_tls obtains the TLS configuration if one is present,
 // or returns NNG_EINVAL.  The supplied TLS configuration object may
 // be invalidated by any future calls to nni_http_client_set_tls.
-extern int nni_http_client_get_tls(
+extern nng_err nni_http_client_get_tls(
     nni_http_client *, struct nng_tls_config **);
 
 extern int nni_http_client_set(
@@ -363,24 +363,22 @@ extern const char     *nni_http_get_reason(nng_http *);
 
 // nni_http_set_error flags an error using the built in HTML page.
 // unless body is not NULL.  To pass no content, pass an empty string for body.
-extern int nni_http_set_error(nng_http *conn, nng_http_status status,
+extern nng_err nni_http_set_error(nng_http *conn, nng_http_status status,
     const char *reason, const char *body);
 
 // nni_http_set_redirect is used to set the redirection.
 // It uses a built-in error page, with a message about the redirection, and
 // sets the response Location: header accordingly.
-extern int nni_http_set_redirect(nng_http *conn, nng_http_status status,
+extern nng_err nni_http_set_redirect(nng_http *conn, nng_http_status status,
     const char *reason, const char *dest);
 
-extern int nni_http_set_uri(
+extern nng_err nni_http_set_uri(
     nng_http *conn, const char *uri, const char *query);
 extern const char *nni_http_get_uri(nng_http *conn);
 
 extern void nni_http_set_host(nng_http *conn, const char *);
 extern void nni_http_set_content_type(nng_http *conn, const char *);
 extern void nni_http_conn_reset(nng_http *conn);
-extern int  nni_http_add_header(
-     nng_http *conn, const char *key, const char *val);
 
 extern void nni_http_set_static_header(
     nng_http *conn, nni_http_header *header, const char *key, const char *val);
diff --git a/src/supplemental/http/http_chunk.c b/src/supplemental/http/http_chunk.c
index 20644d37..1d4335db 100644
--- a/src/supplemental/http/http_chunk.c
+++ b/src/supplemental/http/http_chunk.c
@@ -1,5 +1,5 @@
 //
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2025 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 //
 // This software is supplied under the terms of the MIT License, a
@@ -54,10 +54,10 @@ struct nng_http_chunk {
 	size_t        c_size;
 	size_t        c_alloc;
 	size_t        c_resid; // residual data to transfer
-	char *        c_data;
+	char         *c_data;
 };
 
-int
+nng_err
 nni_http_chunks_init(nni_http_chunks **clp, size_t maxsz)
 {
 	nni_http_chunks *cl;
@@ -68,7 +68,7 @@ nni_http_chunks_init(nni_http_chunks **clp, size_t maxsz)
 	NNI_LIST_INIT(&cl->cl_chunks, nni_http_chunk, c_node);
 	cl->cl_maxsz = maxsz;
 	*clp         = cl;
-	return (0);
+	return (NNG_OK);
 }
 
 void
@@ -120,7 +120,7 @@ nni_http_chunk_data(nni_http_chunk *ch)
 	return (ch->c_data);
 }
 
-static int
+static nng_err
 chunk_ingest_len(nni_http_chunks *cl, char c)
 {
 	if (isdigit(c)) {
@@ -139,10 +139,10 @@ chunk_ingest_len(nni_http_chunks *cl, char c)
 	} else {
 		return (NNG_EPROTO);
 	}
-	return (0);
+	return (NNG_OK);
 }
 
-static int
+static nng_err
 chunk_ingest_ext(nni_http_chunks *cl, char c)
 {
 	if (c == '\r') {
@@ -150,10 +150,10 @@ chunk_ingest_ext(nni_http_chunks *cl, char c)
 	} else if (!isprint(c)) {
 		return (NNG_EPROTO);
 	}
-	return (0);
+	return (NNG_OK);
 }
 
-static int
+static nng_err
 chunk_ingest_newline(nni_http_chunks *cl, char c)
 {
 	nni_http_chunk *chunk;
@@ -164,7 +164,7 @@ chunk_ingest_newline(nni_http_chunks *cl, char c)
 	if (cl->cl_size == 0) {
 		cl->cl_line  = 0;
 		cl->cl_state = CS_TRLR;
-		return (0);
+		return (NNG_OK);
 	}
 	if ((cl->cl_maxsz > 0) &&
 	    ((nni_http_chunks_size(cl) + cl->cl_size) > cl->cl_maxsz)) {
@@ -188,24 +188,24 @@ chunk_ingest_newline(nni_http_chunks *cl, char c)
 	chunk->c_resid = chunk->c_alloc;
 	nni_list_append(&cl->cl_chunks, chunk);
 
-	return (0);
+	return (NNG_OK);
 }
 
-static int
+static nng_err
 chunk_ingest_trailer(nni_http_chunks *cl, char c)
 {
 	if (c == '\r') {
 		cl->cl_state = CS_TRLRCR;
-		return (0);
+		return (NNG_OK);
 	}
 	if (!isprint(c)) {
 		return (NNG_EPROTO);
 	}
 	cl->cl_line++;
-	return (0);
+	return (NNG_OK);
 }
 
-static int
+static nng_err
 chunk_ingest_trailercr(nni_http_chunks *cl, char c)
 {
 	if (c != '\n') {
@@ -217,13 +217,13 @@ chunk_ingest_trailercr(nni_http_chunks *cl, char c)
 	}
 	cl->cl_line  = 0;
 	cl->cl_state = CS_TRLR;
-	return (0);
+	return (NNG_OK);
 }
 
-static int
+static nng_err
 chunk_ingest_char(nni_http_chunks *cl, char c)
 {
-	int rv;
+	nng_err rv;
 	switch (cl->cl_state) {
 	case CS_INIT:
 		if (!isalnum(c)) {
@@ -257,12 +257,12 @@ chunk_ingest_char(nni_http_chunks *cl, char c)
 	return (rv);
 }
 
-static int
+static nng_err
 chunk_ingest_data(nni_http_chunks *cl, char *buf, size_t n, size_t *lenp)
 {
 	nni_http_chunk *chunk;
 	size_t          offset;
-	char *          dest;
+	char           *dest;
 
 	chunk = nni_list_last(&cl->cl_chunks);
 
@@ -288,20 +288,20 @@ chunk_ingest_data(nni_http_chunks *cl, char *buf, size_t n, size_t *lenp)
 		cl->cl_size    = 0;
 		cl->cl_line    = 0;
 		*lenp          = n;
-		return (0);
+		return (NNG_OK);
 	}
 
 	memcpy(dest, buf, n);
 	chunk->c_resid -= n;
 	*lenp = n;
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_chunks_parse(nni_http_chunks *cl, void *buf, size_t n, size_t *lenp)
 {
 	size_t i   = 0;
-	char * src = buf;
+	char  *src = buf;
 
 	// Format of this data is <hexdigits> [ ; <ascii> CRLF ]
 	// The <ascii> are chunk extensions, and we don't support any.
@@ -315,8 +315,8 @@ nni_http_chunks_parse(nni_http_chunks *cl, void *buf, size_t n, size_t *lenp)
 			break;
 
 		case CS_DATA:
-			if ((rv = chunk_ingest_data(cl, src + i, n - i, &cnt)) !=
-			    0) {
+			if ((rv = chunk_ingest_data(
+			         cl, src + i, n - i, &cnt)) != 0) {
 				return (rv);
 			}
 			i += cnt;
@@ -337,5 +337,5 @@ nni_http_chunks_parse(nni_http_chunks *cl, void *buf, size_t n, size_t *lenp)
 	if (cl->cl_state != CS_DONE) {
 		return (NNG_EAGAIN);
 	}
-	return (0);
+	return (NNG_OK);
 }
diff --git a/src/supplemental/http/http_client.c b/src/supplemental/http/http_client.c
index 4247f4b1..1f5d8fbd 100644
--- a/src/supplemental/http/http_client.c
+++ b/src/supplemental/http/http_client.c
@@ -44,7 +44,7 @@ http_dial_cb(void *arg)
 {
 	nni_http_client *c = arg;
 	nni_aio         *aio;
-	int              rv;
+	nng_err          rv;
 	nng_stream      *stream;
 	nni_http_conn   *conn;
 
@@ -61,7 +61,7 @@ http_dial_cb(void *arg)
 		return;
 	}
 
-	if (rv != 0) {
+	if (rv != NNG_OK) {
 		nni_aio_list_remove(aio);
 		http_dial_start(c);
 		nni_mtx_unlock(&c->mtx);
@@ -73,20 +73,20 @@ http_dial_cb(void *arg)
 	stream = nni_aio_get_output(&c->aio, 0);
 	NNI_ASSERT(stream != NULL);
 
-	rv = nni_http_conn_init(&conn, stream, true);
+	rv = nni_http_init(&conn, stream, true);
 
 	// set up the host header
 	http_dial_start(c);
 	nni_mtx_unlock(&c->mtx);
 
-	if (rv != 0) {
+	if (rv != NNG_OK) {
 		// the conn_init function will have already discard stream.
 		nni_aio_finish_error(aio, rv);
 		return;
 	}
 	nni_http_set_host(conn, c->host);
 	nni_aio_set_output(aio, 0, conn);
-	nni_aio_finish(aio, 0, 0);
+	nni_aio_finish(aio, NNG_OK, 0);
 }
 
 void
@@ -100,10 +100,10 @@ nni_http_client_fini(nni_http_client *c)
 	NNI_FREE_STRUCT(c);
 }
 
-int
+nng_err
 nni_http_client_init(nni_http_client **cp, const nng_url *url)
 {
-	int              rv;
+	nng_err          rv;
 	nni_http_client *c;
 	nng_url          my_url;
 	const char      *scheme;
@@ -144,16 +144,16 @@ nni_http_client_init(nni_http_client **cp, const nng_url *url)
 	}
 
 	*cp = c;
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_client_set_tls(nni_http_client *c, nng_tls_config *tls)
 {
 	return (nng_stream_dialer_set_tls(c->dialer, tls));
 }
 
-int
+nng_err
 nni_http_client_get_tls(nni_http_client *c, nng_tls_config **tlsp)
 {
 	return (nng_stream_dialer_get_tls(c->dialer, tlsp));
@@ -268,7 +268,7 @@ http_txn_cb(void *arg)
 	http_txn       *txn = arg;
 	const char     *str;
 	char           *end;
-	int             rv;
+	nng_err         rv;
 	uint64_t        len;
 	nni_iov         iov;
 	char           *dst;
@@ -276,7 +276,7 @@ http_txn_cb(void *arg)
 	nni_http_chunk *chunk = NULL;
 
 	nni_mtx_lock(&http_txn_lk);
-	if ((rv = nni_aio_result(&txn->aio)) != 0) {
+	if ((rv = nni_aio_result(&txn->aio)) != NNG_OK) {
 		http_txn_finish_aios(txn, rv);
 		nni_mtx_unlock(&http_txn_lk);
 		http_txn_fini(txn);
@@ -299,7 +299,7 @@ http_txn_cb(void *arg)
 		    (strstr(str, "chunked") != NULL)) {
 
 			if ((rv = nni_http_chunks_init(&txn->chunks, 0)) !=
-			    0) {
+			    NNG_OK) {
 				goto error;
 			}
 			txn->state = HTTP_RECVING_CHUNKS;
@@ -323,7 +323,7 @@ http_txn_cb(void *arg)
 		}
 
 		if ((rv = nni_http_res_alloc_data(txn->res, (size_t) len)) !=
-		    0) {
+		    NNG_OK) {
 			goto error;
 		}
 		nni_http_get_body(txn->conn, &iov.iov_buf, &iov.iov_len);
diff --git a/src/supplemental/http/http_conn.c b/src/supplemental/http/http_conn.c
index 169ac75e..00961852 100644
--- a/src/supplemental/http/http_conn.c
+++ b/src/supplemental/http/http_conn.c
@@ -174,13 +174,13 @@ http_buf_pull_up(nni_http_conn *conn)
 }
 
 // http_rd_buf attempts to satisfy the read from data in the buffer.
-static int
+static nng_err
 http_rd_buf(nni_http_conn *conn, nni_aio *aio)
 {
 	size_t   cnt = conn->rd_put - conn->rd_get;
 	size_t   n;
 	uint8_t *rbuf = conn->buf;
-	int      rv;
+	nng_err  rv;
 	bool     raw = false;
 	nni_iov *iov;
 	unsigned nio;
@@ -218,7 +218,7 @@ http_rd_buf(nni_http_conn *conn, nni_aio *aio)
 			// Finished the read.  (We are finished if we either
 			// got *all* the data, or we got *some* data for
 			// a raw read.)
-			return (0);
+			return (NNG_OK);
 		}
 
 		// No more data left in the buffer, so use a physio.
@@ -247,7 +247,7 @@ http_rd_buf(nni_http_conn *conn, nni_aio *aio)
 			nng_stream_recv(conn->sock, &conn->rd_aio);
 			return (NNG_EAGAIN);
 		}
-		return (0);
+		return (NNG_OK);
 
 	case HTTP_RD_REQ:
 		conn->client = true;
@@ -349,7 +349,7 @@ http_rd_start(nni_http_conn *conn)
 			return;
 		case 0:
 			conn->rd_uaio = NULL;
-			nni_aio_finish(aio, 0, nni_aio_count(aio));
+			nni_aio_finish(aio, NNG_OK, nni_aio_count(aio));
 			break;
 		default:
 			conn->rd_uaio = NULL;
@@ -367,7 +367,7 @@ http_rd_cb(void *arg)
 	nni_aio       *aio  = &conn->rd_aio;
 	nni_aio       *uaio;
 	size_t         cnt;
-	int            rv;
+	nng_err        rv;
 	unsigned       niov;
 	nni_iov       *iov;
 
@@ -495,14 +495,14 @@ http_wr_cb(void *arg)
 	nni_http_conn *conn = arg;
 	nni_aio       *aio  = &conn->wr_aio;
 	nni_aio       *uaio;
-	int            rv;
+	nng_err        rv;
 	size_t         n;
 
 	nni_mtx_lock(&conn->mtx);
 
 	uaio = conn->wr_uaio;
 
-	if ((rv = nni_aio_result(aio)) != 0) {
+	if ((rv = nni_aio_result(aio)) != NNG_OK) {
 		// We failed to complete the aio.
 		if (uaio != NULL) {
 			conn->wr_uaio = NULL;
@@ -540,7 +540,7 @@ http_wr_cb(void *arg)
 
 done:
 	conn->wr_uaio = NULL;
-	nni_aio_finish(uaio, 0, nni_aio_count(uaio));
+	nni_aio_finish(uaio, NNG_OK, nni_aio_count(uaio));
 
 	// Start next write if another is ready.
 	http_wr_start(conn);
@@ -724,7 +724,7 @@ http_snprintf(nng_http *conn, char *buf, size_t sz)
 	return (len);
 }
 
-static int
+static nng_err
 http_prepare(nng_http *conn, void **data, size_t *szp)
 {
 	size_t len;
@@ -738,7 +738,7 @@ http_prepare(nng_http *conn, void **data, size_t *szp)
 		http_snprintf(conn, (char *) conn->buf, conn->bufsz);
 		*data = conn->buf;
 		*szp  = len;
-		return (0);
+		return (NNG_OK);
 	}
 
 	// we have to allocate.
@@ -747,13 +747,13 @@ http_prepare(nng_http *conn, void **data, size_t *szp)
 	}
 	http_snprintf(conn, *data, len + 1);
 	*szp = len; // this does not include the terminating null
-	return (0);
+	return (NNG_OK);
 }
 
 void
 nni_http_write_req(nng_http *conn, nni_aio *aio)
 {
-	int     rv;
+	nng_err rv;
 	void   *buf;
 	size_t  bufsz;
 	nni_iov iov[2];
@@ -786,7 +786,7 @@ nni_http_write_req(nng_http *conn, nni_aio *aio)
 void
 nni_http_write_res(nng_http *conn, nni_aio *aio)
 {
-	int     rv;
+	nng_err rv;
 	void   *buf;
 	size_t  bufsz;
 	nni_iov iov[2];
@@ -857,7 +857,7 @@ nni_http_set_version(nng_http *conn, const char *vers)
 	for (int i = 0; http_versions[i] != NULL; i++) {
 		if (strcmp(vers, http_versions[i]) == 0) {
 			conn->vers = http_versions[i];
-			return (0);
+			return (NNG_OK);
 		}
 	}
 	return (NNG_ENOTSUP);
@@ -883,10 +883,7 @@ nni_http_get_method(nng_http *conn)
 nng_http_status
 nni_http_get_status(nng_http *conn)
 {
-	if (conn->code == 0) {
-		return (NNG_HTTP_STATUS_OK);
-	}
-	return (conn->code);
+	return (conn->code ? conn->code : NNG_HTTP_STATUS_OK);
 }
 
 const char *
@@ -1076,19 +1073,20 @@ http_conn_set_error(nng_http *conn, nng_http_status status, const char *reason,
 	}
 	if (strlen(body) > 0) {
 		nni_http_set_content_type(conn, "text/html; charset=UTF-8");
-		return (nni_http_copy_body(conn, body, strlen(body)));
+		// if the follow fails, live with it (ENOMEM, so no body).
+		(void) nni_http_copy_body(conn, body, strlen(body));
 	}
 	return (0);
 }
 
-int
+nng_err
 nni_http_set_error(nng_http *conn, nng_http_status status, const char *reason,
     const char *body)
 {
 	return (http_conn_set_error(conn, status, reason, body, NULL));
 }
 
-int
+nng_err
 nni_http_set_redirect(nng_http *conn, nng_http_status status,
     const char *reason, const char *redirect)
 {
@@ -1158,7 +1156,7 @@ nni_http_get_uri(nng_http *conn)
 	return ((conn->uri && conn->uri[0]) ? conn->uri : "/");
 }
 
-int
+nng_err
 nni_http_set_uri(nng_http *conn, const char *uri, const char *query)
 {
 	size_t      needed;
@@ -1176,7 +1174,7 @@ nni_http_set_uri(nng_http *conn, const char *uri, const char *query)
 	if (conn->uri != NULL && (strcmp(uri, conn->uri) == 0) &&
 	    strlen(query) == 0) {
 		// no change, do nothing
-		return (0);
+		return (NNG_OK);
 	}
 	if (conn->uri != NULL && conn->uri != conn->ubuf) {
 		nni_strfree(conn->uri);
@@ -1186,17 +1184,17 @@ nni_http_set_uri(nng_http *conn, const char *uri, const char *query)
 	if (needed < sizeof(conn->ubuf)) {
 		snprintf(conn->ubuf, sizeof(conn->ubuf), fmt, uri, query);
 		conn->uri = conn->ubuf;
-		return (0);
+		return (NNG_OK);
 	}
 
 	// too big, we have to allocate it (slow path)
 	if (nni_asprintf(&conn->uri, fmt, uri, query) != 0) {
 		return (NNG_ENOMEM);
 	}
-	return (0);
+	return (NNG_OK);
 }
 
-static int
+static nng_err
 http_set_header(nng_http *conn, const char *key, const char *val)
 {
 	nni_http_entity *data =
@@ -1214,7 +1212,7 @@ http_set_header(nng_http *conn, const char *key, const char *val)
 				h->value = NULL;
 			}
 			h->value = news;
-			return (0);
+			return (NNG_OK);
 		}
 	}
 
@@ -1232,10 +1230,10 @@ http_set_header(nng_http *conn, const char *key, const char *val)
 		return (NNG_ENOMEM);
 	}
 	nni_list_append(&data->hdrs, h);
-	return (0);
+	return (NNG_OK);
 }
 
-static int
+static nng_err
 http_add_header(nng_http *conn, const char *key, const char *val)
 {
 	nni_http_entity *data =
@@ -1246,14 +1244,14 @@ http_add_header(nng_http *conn, const char *key, const char *val)
 			char *news;
 			int   rv;
 			rv = nni_asprintf(&news, "%s, %s", h->value, val);
-			if (rv != 0) {
+			if (rv != NNG_OK) {
 				return (rv);
 			}
 			if (!h->static_value) {
 				nni_strfree(h->value);
 			}
 			h->value = news;
-			return (0);
+			return (NNG_OK);
 		}
 	}
 
@@ -1271,7 +1269,7 @@ http_add_header(nng_http *conn, const char *key, const char *val)
 		return (NNG_ENOMEM);
 	}
 	nni_list_append(&data->hdrs, h);
-	return (0);
+	return (NNG_OK);
 }
 
 static bool
@@ -1299,11 +1297,11 @@ http_set_known_header(nng_http *conn, const char *key, const char *val)
 	return (false);
 }
 
-int
+nng_err
 nni_http_add_header(nng_http *conn, const char *key, const char *val)
 {
 	if (http_set_known_header(conn, key, val)) {
-		return (0);
+		return (NNG_OK);
 	}
 
 	return (http_add_header(conn, key, val));
@@ -1330,7 +1328,7 @@ nni_http_set_static_header(
 	nni_list_append(headers, h);
 }
 
-int
+nng_err
 nni_http_set_header(nng_http *conn, const char *key, const char *val)
 {
 	if (http_set_known_header(conn, key, val)) {
@@ -1407,7 +1405,7 @@ http_set_data(nni_http_entity *entity, const void *data, size_t size)
 	entity->own  = false;
 }
 
-static int
+static nng_err
 http_alloc_data(nni_http_entity *entity, size_t size)
 {
 	void *newdata;
@@ -1418,13 +1416,13 @@ http_alloc_data(nni_http_entity *entity, size_t size)
 	}
 	http_set_data(entity, newdata, size);
 	entity->own = true;
-	return (0);
+	return (NNG_OK);
 }
 
-static int
+static nng_err
 http_copy_data(nni_http_entity *entity, const void *data, size_t size)
 {
-	int rv;
+	nng_err rv;
 	if ((rv = http_alloc_data(entity, size)) == 0) {
 		memcpy(entity->data, data, size);
 	}
@@ -1454,16 +1452,16 @@ nni_http_prune_body(nng_http *conn)
 	}
 }
 
-int
+nng_err
 nni_http_copy_body(nng_http *conn, const void *data, size_t size)
 {
-	int rv;
+	nng_err rv;
 	if (conn->client) {
 		rv = http_copy_data(&conn->req.data, data, size);
 	} else {
 		rv = http_copy_data(&conn->res.data, data, size);
 	}
-	if (rv == 0) {
+	if (rv == NNG_OK) {
 		nni_http_set_content_length(conn, size);
 	}
 	return (rv);
@@ -1506,7 +1504,7 @@ nni_http_conn_fini(nni_http_conn *conn)
 	NNI_FREE_STRUCT(conn);
 }
 
-static int
+static nng_err
 http_init(nni_http_conn **connp, nng_stream *data, bool client)
 {
 	nni_http_conn *conn;
@@ -1536,14 +1534,14 @@ http_init(nni_http_conn **connp, nng_stream *data, bool client)
 
 	*connp = conn;
 
-	return (0);
+	return (NNG_OK);
 }
 
-int
-nni_http_conn_init(nni_http_conn **connp, nng_stream *stream, bool client)
+nng_err
+nni_http_init(nng_http **connp, nng_stream *stream, bool client)
 {
-	int rv;
-	if ((rv = http_init(connp, stream, client)) != 0) {
+	nng_err rv;
+	if ((rv = http_init(connp, stream, client)) != NNG_OK) {
 		nng_stream_free(stream);
 	}
 	return (rv);
diff --git a/src/supplemental/http/http_msg.c b/src/supplemental/http/http_msg.c
index 0cef876a..09470e31 100644
--- a/src/supplemental/http/http_msg.c
+++ b/src/supplemental/http/http_msg.c
@@ -88,7 +88,7 @@ http_entity_set_data(nni_http_entity *entity, const void *data, size_t size)
 	entity->own  = false;
 }
 
-static int
+static nng_err
 http_entity_alloc_data(nni_http_entity *entity, size_t size)
 {
 	void *newdata;
@@ -99,35 +99,25 @@ http_entity_alloc_data(nni_http_entity *entity, size_t size)
 	}
 	http_entity_set_data(entity, newdata, size);
 	entity->own = true;
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_req_alloc_data(nni_http_req *req, size_t size)
 {
-	int rv;
-
-	if ((rv = http_entity_alloc_data(&req->data, size)) != 0) {
-		return (rv);
-	}
-	return (0);
+	return (http_entity_alloc_data(&req->data, size));
 }
 
 // nni_http_res_alloc_data allocates the data region, but does not update any
 // headers.  The intended use is for client implementations that want to
 // allocate a buffer to receive the entity into.
-int
+nng_err
 nni_http_res_alloc_data(nni_http_res *res, size_t size)
 {
-	int rv;
-
-	if ((rv = http_entity_alloc_data(&res->data, size)) != 0) {
-		return (rv);
-	}
-	return (0);
+	return (http_entity_alloc_data(&res->data, size));
 }
 
-static int
+static nng_err
 http_parse_header(nng_http *conn, void *line)
 {
 	char *key = line;
@@ -219,31 +209,31 @@ http_req_parse_line(nng_http *conn, void *line)
 
 	if (nni_http_get_status(conn) >= NNG_HTTP_STATUS_BAD_REQUEST) {
 		// we've already failed it, nothing else for us to do
-		return (0);
+		return (NNG_OK);
 	}
 	method = line;
 	if ((uri = strchr(method, ' ')) == NULL) {
 		nni_http_set_status(conn, NNG_HTTP_STATUS_BAD_REQUEST, NULL);
-		return (0);
+		return (NNG_OK);
 	}
 	*uri = '\0';
 	uri++;
 
 	if ((version = strchr(uri, ' ')) == NULL) {
 		nni_http_set_status(conn, NNG_HTTP_STATUS_BAD_REQUEST, NULL);
-		return (0);
+		return (NNG_OK);
 	}
 	*version = '\0';
 	version++;
 
 	if (nni_url_canonify_uri(uri) != 0) {
 		nni_http_set_status(conn, NNG_HTTP_STATUS_BAD_REQUEST, NULL);
-		return (0);
+		return (NNG_OK);
 	}
 	if (nni_http_set_version(conn, version)) {
 		nni_http_set_status(
 		    conn, NNG_HTTP_STATUS_HTTP_VERSION_NOT_SUPP, NULL);
-		return (0);
+		return (NNG_OK);
 	}
 
 	nni_http_set_method(conn, method);
@@ -289,7 +279,7 @@ http_res_parse_line(nng_http *conn, uint8_t *line)
 // required, or NNG_ENOMEM on memory exhaustion.  Note that lenp may
 // be updated even in the face of errors (esp. NNG_EAGAIN, which is
 // not an error so much as a request for more data.)
-int
+nng_err
 nni_http_req_parse(nng_http *conn, void *buf, size_t n, size_t *lenp)
 {
 
@@ -328,7 +318,7 @@ nni_http_req_parse(nng_http *conn, void *buf, size_t n, size_t *lenp)
 	return (rv);
 }
 
-int
+nng_err
 nni_http_res_parse(nng_http *conn, void *buf, size_t n, size_t *lenp)
 {
 
diff --git a/src/supplemental/http/http_server.c b/src/supplemental/http/http_server.c
index ce696ac5..53da78c2 100644
--- a/src/supplemental/http/http_server.c
+++ b/src/supplemental/http/http_server.c
@@ -104,7 +104,7 @@ static nni_reap_list http_server_reap_list = {
 	.rl_func   = (nni_cb) http_server_fini,
 };
 
-int
+nng_err
 nni_http_handler_init(
     nni_http_handler **hp, const char *uri, nng_http_handler_func cb)
 {
@@ -131,7 +131,7 @@ nni_http_handler_init(
 	(void) strcpy(h->method, "GET");
 	(void) strcpy(h->host, "");
 	*hp = h;
-	return (0);
+	return (NNG_OK);
 }
 
 // nni_http_handler_fini just drops the reference count, only destroying
@@ -287,7 +287,7 @@ http_sconn_txdatdone(void *arg)
 	http_sconn *sc  = arg;
 	nni_aio    *aio = &sc->txdataio;
 
-	if (nni_aio_result(aio) != 0) {
+	if (nni_aio_result(aio) != NNG_OK) {
 		http_sconn_close(sc);
 		return;
 	}
@@ -307,7 +307,7 @@ http_sconn_txdone(void *arg)
 	http_sconn *sc  = arg;
 	nni_aio    *aio = &sc->txaio;
 
-	if (nni_aio_result(aio) != 0) {
+	if (nni_aio_result(aio) != NNG_OK) {
 		http_sconn_close(sc);
 		return;
 	}
@@ -342,7 +342,7 @@ http_sconn_error(http_sconn *sc, nng_http_status err)
 	nni_http_write_res(sc->conn, &sc->txaio);
 }
 
-int
+nng_err
 nni_http_hijack(nni_http_conn *conn)
 {
 	http_sconn *sc;
@@ -356,7 +356,7 @@ nni_http_hijack(nni_http_conn *conn)
 		sc->conn = NULL;
 		nni_mtx_unlock(&s->mtx);
 	}
-	return (0);
+	return (NNG_OK);
 }
 
 static bool
@@ -432,7 +432,7 @@ http_sconn_rxdone(void *arg)
 	const char       *host;
 	const char       *cls;
 
-	if ((rv = nni_aio_result(aio)) != 0) {
+	if ((rv = nni_aio_result(aio)) != NNG_OK) {
 		http_sconn_close(sc);
 		return;
 	}
@@ -680,11 +680,11 @@ http_sconn_cbdone(void *arg)
 	}
 }
 
-static int
+static nng_err
 http_sconn_init(http_sconn **scp, nng_stream *stream)
 {
 	http_sconn *sc;
-	int         rv;
+	nng_err     rv;
 
 	if ((sc = NNI_ALLOC_STRUCT(sc)) == NULL) {
 		nng_stream_free(stream);
@@ -696,7 +696,7 @@ http_sconn_init(http_sconn **scp, nng_stream *stream)
 	nni_aio_init(&sc->txdataio, http_sconn_txdatdone, sc);
 	nni_aio_init(&sc->cbaio, http_sconn_cbdone, sc);
 
-	if ((rv = nni_http_conn_init(&sc->conn, stream, false)) != 0) {
+	if ((rv = nni_http_init(&sc->conn, stream, false)) != 0) {
 		// Can't even accept the incoming request.  Hard close.
 		http_sconn_close(sc);
 		return (rv);
@@ -704,7 +704,7 @@ http_sconn_init(http_sconn **scp, nng_stream *stream)
 
 	nni_http_conn_set_ctx(sc->conn, sc);
 	*scp = sc;
-	return (0);
+	return (NNG_OK);
 }
 
 static void
@@ -780,11 +780,11 @@ http_server_fini(nni_http_server *s)
 	NNI_FREE_STRUCT(s);
 }
 
-static int
+static nng_err
 http_server_init(nni_http_server **serverp, const nng_url *url)
 {
 	nni_http_server *s;
-	int              rv;
+	nng_err          rv;
 	nng_url          my_url;
 	const char      *scheme;
 
@@ -822,13 +822,13 @@ http_server_init(nni_http_server **serverp, const nng_url *url)
 
 	s->refcnt = 1;
 	*serverp  = s;
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_server_init(nni_http_server **serverp, const nng_url *url)
 {
-	int              rv;
+	nng_err          rv;
 	nni_http_server *s;
 
 	nni_mtx_lock(&http_servers_lk);
@@ -840,7 +840,7 @@ nni_http_server_init(nni_http_server **serverp, const nng_url *url)
 			s->refcnt++;
 			nni_mtx_unlock(&s->mtx);
 			nni_mtx_unlock(&http_servers_lk);
-			return (0);
+			return (NNG_OK);
 		}
 		nni_mtx_unlock(&s->mtx);
 	}
@@ -855,10 +855,10 @@ nni_http_server_init(nni_http_server **serverp, const nng_url *url)
 	return (rv);
 }
 
-static int
+static nng_err
 http_server_start(nni_http_server *s)
 {
-	int rv;
+	nng_err rv;
 	if ((rv = nng_stream_listener_listen(s->listener)) != 0) {
 		return (rv);
 	}
@@ -869,19 +869,19 @@ http_server_start(nni_http_server *s)
 		s->port = (uint32_t) port;
 	}
 	nng_stream_listener_accept(s->listener, &s->accaio);
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_server_start(nni_http_server *s)
 {
-	int rv = 0;
+	int rv = NNG_OK;
 
 	nni_mtx_lock(&s->mtx);
 	if (s->starts == 0) {
 		rv = http_server_start(s);
 	}
-	if (rv == 0) {
+	if (rv == NNG_OK) {
 		s->starts++;
 	}
 	nni_mtx_unlock(&s->mtx);
@@ -946,7 +946,7 @@ nni_http_server_close(nni_http_server *s)
 	nni_mtx_unlock(&s->mtx);
 }
 
-static int
+static nng_err
 http_server_set_err(nni_http_server *s, nng_http_status code, char *body)
 {
 	http_error *epage;
@@ -968,15 +968,15 @@ http_server_set_err(nni_http_server *s, nng_http_status code, char *body)
 	nni_strfree(epage->body);
 	epage->body = body;
 	nni_mtx_unlock(&s->errors_mtx);
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_server_set_error_page(
     nni_http_server *s, nng_http_status code, const char *html)
 {
-	char *body;
-	int   rv;
+	char   *body;
+	nng_err rv;
 
 	// We copy the content, without the trailing NUL.
 	if ((body = nni_strdup(html)) == NULL) {
@@ -988,13 +988,13 @@ nni_http_server_set_error_page(
 	return (rv);
 }
 
-int
+nng_err
 nni_http_server_error(nni_http_server *s, nng_http *conn)
 {
 	http_error     *epage;
 	char           *body = NULL;
 	nng_http_status code = nni_http_get_status(conn);
-	int             rv;
+	nng_err         rv;
 
 	nni_mtx_lock(&s->errors_mtx);
 	NNI_LIST_FOREACH (&s->errors, epage) {
@@ -1008,7 +1008,7 @@ nni_http_server_error(nni_http_server *s, nng_http *conn)
 	return (rv);
 }
 
-int
+nng_err
 nni_http_server_add_handler(nni_http_server *s, nni_http_handler *h)
 {
 	nni_http_handler *h2;
@@ -1062,13 +1062,13 @@ nni_http_server_add_handler(nni_http_server *s, nni_http_handler *h)
 	nni_atomic_set_bool(&h->busy, true);
 
 	nni_mtx_unlock(&s->mtx);
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_server_del_handler(nni_http_server *s, nni_http_handler *h)
 {
-	int               rv = NNG_ENOENT;
+	nng_err           rv = NNG_ENOENT;
 	nni_http_handler *srch;
 	nni_mtx_lock(&s->mtx);
 	NNI_LIST_FOREACH (&s->handlers, srch) {
@@ -1076,7 +1076,7 @@ nni_http_server_del_handler(nni_http_server *s, nni_http_handler *h)
 			// NB: We are giving the caller our reference
 			// on the handler.
 			nni_list_remove(&s->handlers, h);
-			rv = 0;
+			rv = NNG_OK;
 			break;
 		}
 	}
@@ -1187,7 +1187,7 @@ http_handle_file(nng_http *conn, void *arg, nni_aio *aio)
 			nni_aio_finish_error(aio, rv);
 			return;
 		}
-		nni_aio_finish(aio, 0, 0);
+		nni_aio_finish(aio, NNG_OK, 0);
 		return;
 	}
 	if (((rv = nni_http_set_header(conn, "Content-Type", ctype)) != 0) ||
@@ -1200,7 +1200,7 @@ http_handle_file(nng_http *conn, void *arg, nni_aio *aio)
 	nng_http_set_status(conn, NNG_HTTP_STATUS_OK, NULL);
 
 	nni_free(data, size);
-	nni_aio_finish(aio, 0, 0);
+	nni_aio_finish(aio, NNG_OK, 0);
 }
 
 static void
@@ -1215,13 +1215,13 @@ http_file_free(void *arg)
 	}
 }
 
-int
+nng_err
 nni_http_handler_init_file_ctype(nni_http_handler **hpp, const char *uri,
     const char *path, const char *ctype)
 {
 	nni_http_handler *h;
 	http_file        *hf;
-	int               rv;
+	nng_err           rv;
 
 	if ((hf = NNI_ALLOC_STRUCT(hf)) == NULL) {
 		return (NNG_ENOMEM);
@@ -1252,10 +1252,10 @@ nni_http_handler_init_file_ctype(nni_http_handler **hpp, const char *uri,
 	nni_http_handler_collect_body(h, true, 0);
 
 	*hpp = h;
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_handler_init_file(
     nni_http_handler **hpp, const char *uri, const char *path)
 {
@@ -1267,7 +1267,7 @@ http_handle_dir(nng_http *conn, void *arg, nng_aio *aio)
 {
 	void       *data;
 	size_t      size;
-	int         rv;
+	nng_err     rv;
 	http_file  *hf   = arg;
 	const char *path = hf->path;
 	const char *base = hf->base;
@@ -1337,7 +1337,7 @@ http_handle_dir(nng_http *conn, void *arg, nng_aio *aio)
 		}
 	}
 
-	if (rv == 0) {
+	if (rv == NNG_OK) {
 		rv = nni_file_get(pn, &data, &size);
 	} else {
 		data = NULL;
@@ -1349,7 +1349,7 @@ http_handle_dir(nng_http *conn, void *arg, nng_aio *aio)
 	}
 
 	nni_free(pn, pnsz);
-	if (rv != 0) {
+	if (rv != NNG_OK) {
 		nng_http_status status;
 
 		switch (rv) {
@@ -1384,16 +1384,16 @@ http_handle_dir(nng_http *conn, void *arg, nng_aio *aio)
 	nng_http_set_status(conn, NNG_HTTP_STATUS_OK, NULL);
 
 	nni_free(data, size);
-	nni_aio_finish(aio, 0, 0);
+	nni_aio_finish(aio, NNG_OK, 0);
 }
 
-int
+nng_err
 nni_http_handler_init_directory(
     nni_http_handler **hpp, const char *uri, const char *path)
 {
 	http_file        *hf;
 	nni_http_handler *h;
-	int               rv;
+	nng_err           rv;
 
 	if ((hf = NNI_ALLOC_STRUCT(hf)) == NULL) {
 		return (NNG_ENOMEM);
@@ -1414,7 +1414,7 @@ nni_http_handler_init_directory(
 	nng_http_handler_set_data(h, hf, http_file_free);
 
 	*hpp = h;
-	return (0);
+	return (NNG_OK);
 }
 
 typedef struct http_redirect {
@@ -1426,7 +1426,6 @@ typedef struct http_redirect {
 static void
 http_handle_redirect(nng_http *conn, void *data, nng_aio *aio)
 {
-	nni_http_res  *res = nni_http_conn_res(conn);
 	char          *loc = NULL;
 	http_redirect *hr  = data;
 	int            rv;
@@ -1439,7 +1438,7 @@ http_handle_redirect(nng_http *conn, void *data, nng_aio *aio)
 	// If we are doing a full tree, then include the entire suffix.
 	if (strncmp(uri, base, strlen(base)) == 0) {
 		rv = nni_asprintf(&loc, "%s%s", hr->where, uri + strlen(base));
-		if (rv != 0) {
+		if (rv != NNG_OK) {
 			nni_aio_finish_error(aio, rv);
 			return;
 		}
@@ -1465,8 +1464,7 @@ http_handle_redirect(nng_http *conn, void *data, nng_aio *aio)
 	if (loc != hr->where) {
 		nni_strfree(loc);
 	}
-	nni_aio_set_output(aio, 0, res);
-	nni_aio_finish(aio, 0, 0);
+	nni_aio_finish(aio, NNG_OK, 0);
 }
 
 static void
@@ -1481,12 +1479,12 @@ http_redirect_free(void *arg)
 	}
 }
 
-int
+nng_err
 nni_http_handler_init_redirect(nni_http_handler **hpp, const char *uri,
     nng_http_status status, const char *where)
 {
 	nni_http_handler *h;
-	int               rv;
+	nng_err           rv;
 	http_redirect    *hr;
 
 	if ((hr = NNI_ALLOC_STRUCT(hr)) == NULL) {
@@ -1516,7 +1514,7 @@ nni_http_handler_init_redirect(nni_http_handler **hpp, const char *uri,
 	nni_http_handler_collect_body(h, false, 0);
 
 	*hpp = h;
-	return (0);
+	return (NNG_OK);
 }
 
 typedef struct http_static {
@@ -1556,12 +1554,12 @@ http_static_free(void *arg)
 	}
 }
 
-int
+nng_err
 nni_http_handler_init_static(nni_http_handler **hpp, const char *uri,
     const void *data, size_t size, const char *ctype)
 {
 	nni_http_handler *h;
-	int               rv;
+	nng_err           rv;
 	http_static      *hs;
 
 	if ((hs = NNI_ALLOC_STRUCT(hs)) == NULL) {
@@ -1586,16 +1584,16 @@ nni_http_handler_init_static(nni_http_handler **hpp, const char *uri,
 	nni_http_handler_collect_body(h, true, 0);
 
 	*hpp = h;
-	return (0);
+	return (NNG_OK);
 }
 
-int
+nng_err
 nni_http_server_set_tls(nni_http_server *s, nng_tls_config *tls)
 {
 	return (nng_stream_listener_set_tls(s->listener, tls));
 }
 
-int
+nng_err
 nni_http_server_get_tls(nni_http_server *s, nng_tls_config **tlsp)
 {
 	return (nng_stream_listener_get_tls(s->listener, tlsp));