X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=filter.c;h=9c025710656dfa1fb064ced4d364c8acfee219b9;hb=c73d2ea421c2b425c3f0ae33bce2bfd0c448ca5f;hp=5698d333f0eea57de70aa97c5ca5277a1c2f4312;hpb=488a13b110d3563194dd63e087e295a4aa114002;p=libsigrok.git

diff --git a/filter.c b/filter.c
index 5698d333..9c025710 100644
--- a/filter.c
+++ b/filter.c
@@ -1,7 +1,7 @@
 /*
  * This file is part of the sigrok project.
  *
- * Copyright (C) 2010 Bert Vermeulen <bert@biot.com>
+ * Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -20,7 +20,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
-#include <sigrok.h>
+#include "sigrok.h"
 #include "sigrok-internal.h"
 
 /**
@@ -53,6 +53,9 @@
  *
  * @param in_unitsize The unit size (>= 1) of the input (data_in).
  * @param out_unitsize The unit size (>= 1) the output shall have (data_out).
+ *                     The requested unit size must be big enough to hold as
+ *                     much data as is specified by the number of enabled
+ *                     probes in 'probelist'.
  * @param probelist Pointer to a list of integers (probe numbers). The probe
  *                  numbers in this list are 1-based, i.e. the first probe
  *                  is expected to be numbered 1 (not 0!). Must not be NULL.
@@ -70,9 +73,10 @@
  *         If something other than SR_OK is returned, the values of
  *         out_unitsize, data_out, and length_out are undefined.
  */
-int sr_filter_probes(int in_unitsize, int out_unitsize, const int *probelist,
-		     const unsigned char *data_in, uint64_t length_in,
-		     char **data_out, uint64_t *length_out)
+SR_API int sr_filter_probes(int in_unitsize, int out_unitsize,
+			    const int *probelist, const unsigned char *data_in,
+			    uint64_t length_in, char **data_out,
+			    uint64_t *length_out)
 {
 	unsigned int in_offset, out_offset;
 	int num_enabled_probes, out_bit, i;
@@ -98,15 +102,22 @@ int sr_filter_probes(int in_unitsize, int out_unitsize, const int *probelist,
 		return SR_ERR_ARG;
 	}
 
+	num_enabled_probes = 0;
+	for (i = 0; probelist[i]; i++)
+		num_enabled_probes++;
+
+	/* Are there more probes than the target unit size supports? */
+	if (num_enabled_probes > out_unitsize * 8) {
+		sr_err("filter: %s: too many probes (%d) for the target unit "
+		       "size (%d)", num_enabled_probes, out_unitsize, __func__);
+		return SR_ERR_ARG;
+	}
+
 	if (!(*data_out = g_try_malloc(length_in))) {
 		sr_err("filter: %s: data_out malloc failed", __func__);
 		return SR_ERR_MALLOC;
 	}
 
-	num_enabled_probes = 0;
-	for (i = 0; probelist[i]; i++)
-		num_enabled_probes++;
-
 	if (num_enabled_probes == in_unitsize * 8) {
 		/* All probes are used -- no need to compress anything. */
 		memcpy(*data_out, data_in, length_in);