From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Wed, 22 Jun 2022 20:15:08 +0000 (-0500)
Subject: sbuff->shifted should be reinitialised to 0 with each new sbuff in the chain
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cd8e20b25c3bcef5b451824d1e3cea06a3ebe7de;p=thirdparty%2Ffreeradius-server.git

sbuff->shifted should be reinitialised to 0 with each new sbuff in the chain

This breaks the file streaming sbuff, so record the shifted count separately in the fr_sbuff_uctx_file_t structure
---

diff --git a/src/lib/util/sbuff.c b/src/lib/util/sbuff.c
index 2c0cdbc7884..d8288c75566 100644
--- a/src/lib/util/sbuff.c
+++ b/src/lib/util/sbuff.c
@@ -266,7 +266,7 @@ size_t fr_sbuff_extend_file(fr_sbuff_t *sbuff, size_t extension)
 
 	if (extension == SIZE_MAX) extension = 0;
 
-	total_read = sbuff->shifted + (sbuff->end - sbuff->buff);
+	total_read = fctx->shifted + (sbuff->end - sbuff->buff);
 	if (total_read >= fctx->max) {
 		fr_strerror_const("Can't satisfy extension request, max bytes read");
 		return 0;	/* There's no way we could satisfy the extension request */
@@ -279,7 +279,7 @@ size_t fr_sbuff_extend_file(fr_sbuff_t *sbuff, size_t extension)
 		 *
 		 *	Note: p and markers are constraints here.
 		 */
-		fr_sbuff_shift(sbuff, fr_sbuff_used(sbuff));
+		fctx->shifted += fr_sbuff_shift(sbuff, fr_sbuff_used(sbuff));
 	}
 
 	available = fctx->buff_end - sbuff->end;
diff --git a/src/lib/util/sbuff.h b/src/lib/util/sbuff.h
index ef7c5d401f5..77c5bbc3fae 100644
--- a/src/lib/util/sbuff.h
+++ b/src/lib/util/sbuff.h
@@ -124,6 +124,7 @@ typedef struct {
 	FILE			*file;			//!< FILE * we're reading from.
 	char			*buff_end;		//!< The true end of the buffer.
 	size_t			max;			//!< Maximum number of bytes to read.
+	size_t			shifted;		//!< How much we've read from this file.
 	bool			eof;			//!< are we at EOF?
 } fr_sbuff_uctx_file_t;
 
@@ -406,7 +407,7 @@ do { \
 	.p		= (_current), \
 	.is_const 	= fr_sbuff_ptr(_sbuff_or_marker)->is_const, \
 	.adv_parent 	= (_adv_parent), \
-	.shifted	= fr_sbuff_ptr(_sbuff_or_marker)->shifted, \
+	.shifted	= 0, \
 	.extend		= (_extend), \
 	.uctx		= fr_sbuff_ptr(_sbuff_or_marker)->uctx, \
 	.parent 	= fr_sbuff_ptr(_sbuff_or_marker) \
diff --git a/src/lib/util/sbuff_tests.c b/src/lib/util/sbuff_tests.c
index abc75d8c194..754bda62a1d 100644
--- a/src/lib/util/sbuff_tests.c
+++ b/src/lib/util/sbuff_tests.c
@@ -1042,8 +1042,8 @@ static void test_file_extend_max(void)
 	TEST_CHECK(fr_sbuff_init_file(&sbuff, &fctx, buff, sizeof(buff), fp, sizeof(fbuff) - 8) == &sbuff);
 
 	TEST_CASE("Confirm that max stops us from seeing xyzzy");
-	TEST_CHECK_LEN(sizeof(fbuff) - 8, fr_sbuff_adv_past_whitespace(&sbuff, SIZE_MAX, NULL));
-	(void) fr_sbuff_out_abstrncpy(NULL, &post_ws, &sbuff, 24);
+	TEST_CHECK_SLEN(fr_sbuff_adv_past_whitespace(&sbuff, SIZE_MAX, NULL), sizeof(fbuff) - 8);
+	TEST_CHECK_SLEN(fr_sbuff_out_abstrncpy(NULL, &post_ws, &sbuff, 24), 0);
 	TEST_CHECK_STRCMP(post_ws, "");
 	talloc_free(post_ws);
 	fclose(fp);