Improve protocol error diagnostics.

* lib/sockmapstr.c (report_invalid_prefix): New function.
(read_payload_length)
(_sockmap_input_stream_read): Use report_invalid_prefix.

1 files changed, 38 insertions, 6 deletions

diff --git a/lib/sockmapstr.c b/lib/sockmapstr.c
index 906cc1b..16ccbe3 100644
--- a/lib/sockmapstr.c
+++ b/lib/sockmapstr.c
@@ -24,6 +24,10 @@
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
 #include "smap/diag.h"
 #include "smap/stream.h"
 #include "smap/streamdef.h"
@@ -175,6 +179,34 @@ struct sockmap_input_stream {
 	char *debug_pfx;
 };
 
+static void
+report_invalid_prefix(struct sockmap_input_stream *sp, const char *diag)
+{
+	static char buf[1024];
+	size_t n;
+	struct sockaddr_in saddr;
+	socklen_t slen;
+
+	slen = sizeof(saddr);
+	if (getpeername(sp->fd, (struct sockaddr*) &saddr, &slen) != -1) {
+		if (saddr.sin_family == AF_INET)
+			smap_stream_printf(smap_debug_str,
+					   "%s:%d: ",
+					   inet_ntoa(saddr.sin_addr),
+					   ntohs(saddr.sin_port));
+		else if (saddr.sin_family == AF_UNIX)
+			smap_stream_printf(smap_debug_str,
+					   "[local socket]: ");
+	}
+	smap_stream_printf(smap_debug_str,
+			   "sockmap protocol error "
+			   "(%s): %s", diag, sp->nbuf);
+	n = recv(sp->fd, buf, sizeof(buf), 0);
+	if (n > 0)
+		smap_stream_write(smap_debug_str, buf, n, NULL);
+	smap_stream_write(smap_debug_str, "\n", 1, NULL);
+}
+
 int
 read_payload_length(struct sockmap_input_stream *sp)
 {
@@ -204,9 +236,8 @@ read_payload_length(struct sockmap_input_stream *sp)
 	}
 	sp->nbuf[len] = 0;
 	sp->nlen = len;
-	smap_debug(sp->debug_idx, 1,
-		   ("sockmap protocol error (prefix too long): %s",
-		    sp->nbuf));
+	if (smap_debug_np(sp->debug_idx, 1))
+		report_invalid_prefix(sp, "prefix too long");
 	return EPROTO;
 }
 
@@ -242,9 +273,10 @@ _sockmap_input_stream_read(struct _smap_stream *stream, char *buf,
 		for (i = 0; i < sp->cp; i++) {
 			reqsz *= 10;
 			if (!ISDIGIT(sp->nbuf[i])) {
-				smap_debug(sp->debug_idx, 1,
-					   ("sockmap protocol error "
-					    "(invalid prefix): %s", sp->nbuf));
+				if (smap_debug_np(sp->debug_idx, 1))
+					report_invalid_prefix(sp,
+							     "invalid prefix");
+				sp->nlen = sp->cp = sp->reqsz = 0;
 				return EPROTO;
 			}
 			reqsz += sp->nbuf[i] - '0';