torrentd

commit 5278f8f077195cc3da3dacee5b376cdd8e811bb6
parent 8375c04910e59654bc4fee4fbe8a820e1d3f839d
Author: sin <sin@2f30.org>
Date:   Thu, 17 Dec 2015 12:38:07 +0000

Do not kill the process if a parsing error occurs

Diffstat:
M
ben.c
 | 
55
+++++++++++++++++++++++++++++++++++++------------------

1 file changed, 37 insertions(+), 18 deletions(-)
diff --git a/ben.c b/ben.c
@@ -16,6 +16,7 @@
 
 #include <ctype.h>
 #include <err.h>
+#include <setjmp.h>
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -23,6 +24,17 @@
 
 #include "sbtd.h"
 
+static char *parse(char *, char *, struct ben **);
+
+static jmp_buf savesp;
+
+static void
+error(char *msg)
+{
+	fprintf(stderr, "%s\n", msg);
+	longjmp(savesp, 1);
+}
+
 static char *
 parsestr(char *s, char *e, struct ben **b)
 {
@@ -32,11 +44,11 @@ parsestr(char *s, char *e, struct ben **b)
 	for (p = s; p != e && isdigit((int)*p); p++)
 		len = len * 10 + *p - '0';
 	if (p == e)
-		goto eof;
+		error("bad string");
 	if (*p != ':')
-		errx(1, "expected :, got %c", *p);
+		error("expected ':' in string");
 	if (p + len >= e)
-		goto eof;
+		error("bad string");
 	p += len;
 	*b = emalloc(sizeof(**b));
 	(*b)->type = 's';
@@ -45,8 +57,6 @@ parsestr(char *s, char *e, struct ben **b)
 	(*b)->end = p + 1;
 	(*b)->len = len;
 	return p;
-eof:
-	errx(1, "bad string");
 }
 
 static char *
@@ -57,9 +67,9 @@ parseint(char *s, char *e, struct ben **b)
 	int isneg = 0, iszero = 0;
 
 	if (*p != 'i')
-		errx(1, "expected integer");
+		error("expected integer");
 	if (++p == e)
-		errx(1, "bad integer");
+		error("bad integer");
 
 	switch (*p) {
 	case '-':
@@ -77,16 +87,16 @@ parseint(char *s, char *e, struct ben **b)
 	v = 0;
 	while (1) {
 		if (++p == e)
-			errx(1, "bad integer");
+			error("bad integer");
 		if (*p == 'e' || iszero) {
 			if (*p != 'e')
-				errx(1, "0 not followed by e");
+				error("0 not followed by e");
 			break;
 		}
 		if (isneg && *p == '0')
-			errx(1, "i-0 is invalid");
+			error("i-0 is invalid");
 		if (!isdigit((int)*p))
-			errx(1, "unexpected char in integer %c", *p);
+			error("unexpected char in integer");
 		v = v * 10 + *p - '0';
 	}
 
@@ -108,10 +118,10 @@ parsedl(char *s, char *e, struct ben **b)
 
 	memset(&head, 0, sizeof(head));
 	if (*p != 'd' && *p != 'l')
-		errx(1, "expected dictionary or list");
+		error("expected dictionary or list");
 	while (1) {
 		if (++p == e)
-			errx(1, "bad dictionary or list");
+			error("bad dictionary or list");
 		if (*p == 'e')
 			break;
 		bp->next = emalloc(sizeof(*bp));
@@ -122,11 +132,11 @@ parsedl(char *s, char *e, struct ben **b)
 			p = parsestr(p, e, &bp->k);
 			p++;
 		}
-		p = bdecode(p, e, &bp->v);
+		p = parse(p, e, &bp->v);
 		bp->next = NULL;
 	}
 	if (*p != 'e')
-		errx(1, "expected terminator");
+		error("expected terminator");
 
 	*b = head.next;
 	if (!head.next) {
@@ -141,8 +151,8 @@ parsedl(char *s, char *e, struct ben **b)
 	return p;
 }
 
-char *
-bdecode(char *s, char *e, struct ben **b)
+static char *
+parse(char *s, char *e, struct ben **b)
 {
 	if (s == e)
 		return s;
@@ -156,11 +166,20 @@ bdecode(char *s, char *e, struct ben **b)
 		break;
 	default:
 		if (!isdigit((int)*s))
-			errx(1, "unknown type %c", *s);
+			error("unknown type");
 		return parsestr(s, e, b);
 	}
 }
 
+char *
+bdecode(char *s, char *e, struct ben **b)
+{
+	*b = NULL;
+	if (!setjmp(savesp))
+		return parse(s, e, b);
+	return NULL;
+}
+
 void
 bencode(char **buf, size_t *n, struct ben *b)
 {