w-h/0.2.0/large-upload: Add some primitive error checking

Check the status of the open(2) call and return an appropriate HTTP
response code on error.

Signed-off-by: Andrew Clayton <a.clayton@nginx.com>

1 files changed, 33 insertions, 0 deletions

diff --git a/c/wasi-http/0.2.0/large-upload/component.c b/c/wasi-http/0.2.0/large-upload/component.c
index 1030b01..a4eeba6 100644
--- a/c/wasi-http/0.2.0/large-upload/component.c
+++ b/c/wasi-http/0.2.0/large-upload/component.c
@@ -14,6 +14,7 @@
 #include <string.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <errno.h>
 
 #include "proxy.h"
 
@@ -51,6 +52,37 @@ void exports_wasi_http_incoming_handler_handle(
 
 	fd = open("/var/tmp/wasm-wasi-component-upload.dat",
 		  O_CREAT|O_TRUNC|O_WRONLY, 0666);
+	if (fd == -1) {
+		wasi_http_types_status_code_t sc;
+		wasi_http_types_borrow_outgoing_response_t b_resp;
+
+		printf("E: %s (/var/tmp/wasm-wasi-component-upload.dat)\n",
+		       strerror(errno));
+
+		switch (errno) {
+		case EACCES:
+		case EFAULT:
+		case EPERM:
+			sc = 403;
+			break;
+		case EBADF:
+		case ENAMETOOLONG:
+		case ENODEV:
+		case ENOENT:
+		case ENOTDIR:
+			sc = 404;
+			break;
+		default:
+			sc = 500;
+		}
+
+		b_resp = wasi_http_types_borrow_outgoing_response(resp);
+		wasi_http_types_method_outgoing_response_set_status_code(b_resp,
+									 sc);
+		rerr.val.ok = resp;
+
+		goto out_response;
+	}
 
 	b_req = wasi_http_types_borrow_incoming_request(request);
 
@@ -87,6 +119,7 @@ void exports_wasi_http_incoming_handler_handle(
 		total_bytes_wrote += data.len;
 	} while (total_bytes_wrote < content_len);
 
+out_response:
 	wasi_http_types_static_response_outparam_set(response_out, &rerr);
 
 	close(fd);