fix a case where code made assumptions about how memory for variables is

allocatted on the stack - this patch is slightly different than the one
that went in for the trunk

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@28966 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/apps/app_sms.c b/apps/app_sms.c
index 4c15cc185fa28625247f952d2c666e777c85847d..beaf4e2a11ca2b843fa4c1a37f78fda196813762 100644 (file)
--- a/apps/app_sms.c
+++ b/apps/app_sms.c
@@ -1178,25 +1178,24 @@ static void sms_messagetx(sms_t * h)
 static int sms_generate (struct ast_channel *chan, void *data, int len, int samples)
 {
        struct ast_frame f = { 0 };
-       unsigned char waste[AST_FRIENDLY_OFFSET];
+#define MAXSAMPLES 800
 #ifdef OUTALAW
-       unsigned char buf[800];
+       unsigned char *buf;
 #else
-       signed short buf[800];
+       short *buf;
 #endif
+#define SAMPLE2LEN sizeof(*buf)
        sms_t *h = data;
        int i;
 
-       if (len > sizeof (buf)) {
-               ast_log (LOG_WARNING, "Only doing %d bytes (%d bytes requested)\n", (int)(sizeof (buf) / sizeof (signed short)), len);
-               len = sizeof (buf);
-#ifdef OUTALAW
-               samples = len;
-#else
-               samples = len / 2;
-#endif
+       if (samples > MAXSAMPLES) {
+               ast_log (LOG_WARNING, "Only doing %d samples (%d requested)\n",
+                        MAXSAMPLES, samples);
+               samples = MAXSAMPLES;
        }
-       waste[0] = 0;                                    /* make compiler happy */
+       len = samples * SAMPLE2LEN + AST_FRIENDLY_OFFSET;
+       buf = alloca(len);
+
        f.frametype = AST_FRAME_VOICE;
 #ifdef OUTALAW
        f.subclass = AST_FORMAT_ALAW;
@@ -1206,8 +1205,7 @@ static int sms_generate (struct ast_channel *chan, void *data, int len, int samp
        f.datalen = samples * 2;
 #endif
        f.offset = AST_FRIENDLY_OFFSET;
-       f.mallocd = 0;
-       f.data = buf;
+       f.data = buf + AST_FRIENDLY_OFFSET;
        f.samples = samples;
        f.src = "app_sms";
        /* create a buffer containing the digital sms pattern */