From 02ab738c317533f40ea49030f38170eec7e49dda Mon Sep 17 00:00:00 2001
From: Wim Taymans <wtaymans@redhat.com>
Date: Fri, 4 Feb 2022 11:59:57 +0100
Subject: [PATCH 2/2] pulse-server: make sure we don't exceed maxlength

Make sure the various buffer attributes don't exceed maxlength.
Add some SPA_ROUND_UP and SPA_ROUND_DOWN macros.

Fixes #2100
---
 spa/include/spa/utils/defs.h                  |  3 +++
 .../module-protocol-pulse/pulse-server.c      | 25 +++++++++----------
 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/spa/include/spa/utils/defs.h b/spa/include/spa/utils/defs.h
index f37216e73..369dd22a9 100644
--- a/spa/include/spa/utils/defs.h
+++ b/spa/include/spa/utils/defs.h
@@ -228,6 +228,9 @@ struct spa_fraction {
 #define SPA_RESTRICT
 #endif
 
+#define SPA_ROUND_DOWN(num,value)	((num) - ((num) % (value)))
+#define SPA_ROUND_UP(num,value)		((((num) + (value) - 1) / (value)) * (value))
+
 #define SPA_ROUND_DOWN_N(num,align)	((num) & ~((align) - 1))
 #define SPA_ROUND_UP_N(num,align)	SPA_ROUND_DOWN_N((num) + ((align) - 1),align)
 
diff --git a/src/modules/module-protocol-pulse/pulse-server.c b/src/modules/module-protocol-pulse/pulse-server.c
index eedb23901..8f6bc1850 100644
--- a/src/modules/module-protocol-pulse/pulse-server.c
+++ b/src/modules/module-protocol-pulse/pulse-server.c
@@ -374,15 +374,14 @@ static uint32_t fix_playback_buffer_attr(struct stream *s, struct buffer_attr *a
 
 	if (attr->maxlength == (uint32_t) -1 || attr->maxlength > MAXLENGTH)
 		attr->maxlength = MAXLENGTH;
-	attr->maxlength -= attr->maxlength % frame_size;
-	attr->maxlength = SPA_MAX(attr->maxlength, frame_size);
+	attr->maxlength = SPA_ROUND_UP(attr->maxlength, frame_size);
+
+	minreq = SPA_MIN(minreq, attr->maxlength);
 
 	if (attr->tlength == (uint32_t) -1)
 		attr->tlength = frac_to_bytes_round_up(s->default_tlength, &s->ss);
-	if (attr->tlength > attr->maxlength)
-		attr->tlength = attr->maxlength;
-	attr->tlength -= attr->tlength % frame_size;
-	attr->tlength = SPA_MAX(attr->tlength, frame_size);
+	attr->tlength = SPA_MIN(attr->tlength, attr->maxlength);
+	attr->tlength = SPA_ROUND_UP(attr->tlength, frame_size);
 	attr->tlength = SPA_MAX(attr->tlength, minreq);
 
 	if (attr->minreq == (uint32_t) -1) {
@@ -390,13 +389,13 @@ static uint32_t fix_playback_buffer_attr(struct stream *s, struct buffer_attr *a
 		/* With low-latency, tlength/4 gives a decent default in all of traditional,
 		 * adjust latency and early request modes. */
 		uint32_t m = attr->tlength / 4;
-		m -= m % frame_size;
+		m = SPA_ROUND_DOWN(m, frame_size);
 		attr->minreq = SPA_MIN(process, m);
 	}
 	attr->minreq = SPA_MAX(attr->minreq, minreq);
 
 	if (attr->tlength < attr->minreq+frame_size)
-		attr->tlength = attr->minreq + frame_size;
+		attr->tlength = SPA_MIN(attr->minreq + frame_size, attr->maxlength);
 
 	if (s->early_requests) {
 		latency = attr->minreq;
@@ -406,7 +405,7 @@ static uint32_t fix_playback_buffer_attr(struct stream *s, struct buffer_attr *a
 		else
 			latency = attr->minreq;
 
-		latency -= latency % frame_size;
+		latency = SPA_ROUND_DOWN(latency, frame_size);
 
 		if (attr->tlength >= latency)
 			attr->tlength -= latency;
@@ -418,20 +417,20 @@ static uint32_t fix_playback_buffer_attr(struct stream *s, struct buffer_attr *a
 	}
 
 	if (attr->tlength < latency + 2 * attr->minreq)
-		attr->tlength = latency + 2 * attr->minreq;
+		attr->tlength = SPA_MIN(latency + 2 * attr->minreq, attr->maxlength);
 
-	attr->minreq -= attr->minreq % frame_size;
+	attr->minreq = SPA_ROUND_DOWN(attr->minreq, frame_size);
 	if (attr->minreq <= 0) {
 		attr->minreq = frame_size;
 		attr->tlength += frame_size*2;
 	}
 	if (attr->tlength <= attr->minreq)
-		attr->tlength = attr->minreq*2 + frame_size;
+		attr->tlength = SPA_MIN(attr->minreq*2 + frame_size, attr->maxlength);
 
 	max_prebuf = attr->tlength + frame_size - attr->minreq;
 	if (attr->prebuf == (uint32_t) -1 || attr->prebuf > max_prebuf)
 		attr->prebuf = max_prebuf;
-	attr->prebuf -= attr->prebuf % frame_size;
+	attr->prebuf = SPA_ROUND_DOWN(attr->prebuf, frame_size);
 
 	attr->fragsize = 0;
 
-- 
2.34.1