vcs-svn: allow import of > 4GiB files

There is no reason in principle that an svn-format dump would not be
able to represent a file whose length does not fit in a 32-bit
integer.  Use off_t consistently to represent file lengths (in place
of using uint32_t in some contexts) so we can handle that.

Most svn-fe code is already ready to do that without this patch and
passes values of type off_t around.  The type mismatch from stragglers
was noticed with gcc -Wtype-limits.

While at it, tighten the parsing of the Text-content-length field to
make sure it is a number and does not overflow, and tighten other
overflow checks as that value is passed around and manipulated.

Inspired-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

3 files changed, 26 insertions, 14 deletions

diff --git a/vcs-svn/fast_export.c b/vcs-svn/fast_export.c
index 19d7c34c25..b823b8519c 100644
--- a/vcs-svn/fast_export.c
+++ b/vcs-svn/fast_export.c
@@ -227,15 +227,18 @@ static long apply_delta(off_t len, struct line_buffer *input,
 	return ret;
 }
 
-void fast_export_data(uint32_t mode, uint32_t len, struct line_buffer *input)
+void fast_export_data(uint32_t mode, off_t len, struct line_buffer *input)
 {
+	assert(len >= 0);
 	if (mode == REPO_MODE_LNK) {
 		/* svn symlink blobs start with "link " */
+		if (len < 5)
+			die("invalid dump: symlink too short for \"link\" prefix");
 		len -= 5;
 		if (buffer_skip_bytes(input, 5) != 5)
 			die_short_read(input);
 	}
-	printf("data %"PRIu32"\n", len);
+	printf("data %"PRIuMAX"\n", (uintmax_t) len);
 	if (buffer_copy_bytes(input, len) != len)
 		die_short_read(input);
 	fputc('\n', stdout);
@@ -297,12 +300,12 @@ int fast_export_ls(const char *path, uint32_t *mode, struct strbuf *dataref)
 
 void fast_export_blob_delta(uint32_t mode,
 				uint32_t old_mode, const char *old_data,
-				uint32_t len, struct line_buffer *input)
+				off_t len, struct line_buffer *input)
 {
 	long postimage_len;
-	if (len > maximum_signed_value_of_type(off_t))
-		die("enormous delta");
-	postimage_len = apply_delta((off_t) len, input, old_data, old_mode);
+
+	assert(len >= 0);
+	postimage_len = apply_delta(len, input, old_data, old_mode);
 	if (mode == REPO_MODE_LNK) {
 		buffer_skip_bytes(&postimage, strlen("link "));
 		postimage_len -= strlen("link ");
diff --git a/vcs-svn/fast_export.h b/vcs-svn/fast_export.h
index 43d05b65ef..aa629f54ff 100644
--- a/vcs-svn/fast_export.h
+++ b/vcs-svn/fast_export.h
@@ -14,10 +14,10 @@ void fast_export_begin_commit(uint32_t revision, const char *author,
 			const struct strbuf *log, const char *uuid,
 			const char *url, unsigned long timestamp);
 void fast_export_end_commit(uint32_t revision);
-void fast_export_data(uint32_t mode, uint32_t len, struct line_buffer *input);
+void fast_export_data(uint32_t mode, off_t len, struct line_buffer *input);
 void fast_export_blob_delta(uint32_t mode,
 			uint32_t old_mode, const char *old_data,
-			uint32_t len, struct line_buffer *input);
+			off_t len, struct line_buffer *input);
 
 /* If there is no such file at that rev, returns -1, errno == ENOENT. */
 int fast_export_ls_rev(uint32_t rev, const char *path,
diff --git a/vcs-svn/svndump.c b/vcs-svn/svndump.c
index ca63760fe2..644fdc71ba 100644
--- a/vcs-svn/svndump.c
+++ b/vcs-svn/svndump.c
@@ -40,7 +40,8 @@
 static struct line_buffer input = LINE_BUFFER_INIT;
 
 static struct {
-	uint32_t action, propLength, textLength, srcRev, type;
+	uint32_t action, propLength, srcRev, type;
+	off_t text_length;
 	struct strbuf src, dst;
 	uint32_t text_delta, prop_delta;
 } node_ctx;
@@ -61,7 +62,7 @@ static void reset_node_ctx(char *fname)
 	node_ctx.type = 0;
 	node_ctx.action = NODEACT_UNKNOWN;
 	node_ctx.propLength = LENGTH_UNKNOWN;
-	node_ctx.textLength = LENGTH_UNKNOWN;
+	node_ctx.text_length = -1;
 	strbuf_reset(&node_ctx.src);
 	node_ctx.srcRev = 0;
 	strbuf_reset(&node_ctx.dst);
@@ -209,7 +210,7 @@ static void handle_node(void)
 {
 	const uint32_t type = node_ctx.type;
 	const int have_props = node_ctx.propLength != LENGTH_UNKNOWN;
-	const int have_text = node_ctx.textLength != LENGTH_UNKNOWN;
+	const int have_text = node_ctx.text_length != -1;
 	/*
 	 * Old text for this node:
 	 *  NULL	- directory or bug
@@ -291,12 +292,12 @@ static void handle_node(void)
 	}
 	if (!node_ctx.text_delta) {
 		fast_export_modify(node_ctx.dst.buf, node_ctx.type, "inline");
-		fast_export_data(node_ctx.type, node_ctx.textLength, &input);
+		fast_export_data(node_ctx.type, node_ctx.text_length, &input);
 		return;
 	}
 	fast_export_modify(node_ctx.dst.buf, node_ctx.type, "inline");
 	fast_export_blob_delta(node_ctx.type, old_mode, old_data,
-				node_ctx.textLength, &input);
+				node_ctx.text_length, &input);
 }
 
 static void begin_revision(void)
@@ -409,7 +410,15 @@ void svndump_read(const char *url)
 			break;
 		case sizeof("Text-content-length"):
 			if (!constcmp(t, "Text-content-length")) {
-				node_ctx.textLength = atoi(val);
+				char *end;
+				uintmax_t textlen;
+
+				textlen = strtoumax(val, &end, 10);
+				if (!isdigit(*val) || *end)
+					die("invalid dump: non-numeric length %s", val);
+				if (textlen > maximum_signed_value_of_type(off_t))
+					die("unrepresentable length in dump: %s", val);
+				node_ctx.text_length = (off_t) textlen;
 				break;
 			}
 			if (constcmp(t, "Prop-content-length"))