From 7fe72f79f289166b3b23947a198a3f511bf5bf52 Mon Sep 17 00:00:00 2001
From: "Eric S. Raymond" <esr@thyrsus.com>
Date: Sun, 13 Oct 2013 22:28:47 -0400
Subject: Make all hex-dumping truly thread-safe.

---
 hex.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

(limited to 'hex.c')

diff --git a/hex.c b/hex.c
index c4130a66..95f4121d 100644
--- a/hex.c
+++ b/hex.c
@@ -8,7 +8,9 @@
 
 #include "gpsd.h"
 
-const char /*@ observer @*/ *gpsd_packetdump(char *binbuf, size_t binbuflen)
+/*@-mustdefine@*/
+const char /*@ observer @*/ *gpsd_packetdump(char *scbuf, size_t scbuflen,
+					     char *binbuf, size_t binbuflen)
 {
     char *cp;
     bool printable = true;
@@ -20,13 +22,14 @@ const char /*@ observer @*/ *gpsd_packetdump(char *binbuf, size_t binbuflen)
     if (printable)
 	return binbuf;
     else
-	return gpsd_hexdump(binbuf, binbuflen);
+	return gpsd_hexdump(scbuf, scbuflen, binbuf, binbuflen);
 }
+/*@+mustdefine@*/
 
-const char /*@ observer @*/ *gpsd_hexdump(char *binbuf, size_t binbuflen)
+/*@-mustdefine@*/
+const char /*@ observer @*/ *gpsd_hexdump(char *scbuf, size_t scbuflen,
+					  char *binbuf, size_t binbuflen)
 {
-    /* FIXME: this isn't thead-safe! */
-    static char hexbuf[MAX_PACKET_LENGTH * 2 + 1];
 #ifndef SQUELCH_ENABLE
     size_t i, j = 0;
     size_t len =
@@ -39,17 +42,18 @@ const char /*@ observer @*/ *gpsd_hexdump(char *binbuf, size_t binbuflen)
 	return "";
 
     /*@ -shiftimplementation @*/
-    for (i = 0; i < len; i++) {
-	hexbuf[j++] = hexchar[(ibuf[i] & 0xf0) >> 4];
-	hexbuf[j++] = hexchar[ibuf[i] & 0x0f];
+    for (i = 0; i < len && i * 2 < scbuflen - 2; i++) {
+	scbuf[j++] = hexchar[(ibuf[i] & 0xf0) >> 4];
+	scbuf[j++] = hexchar[ibuf[i] & 0x0f];
     }
     /*@ +shiftimplementation @*/
-    hexbuf[j] = '\0';
+    scbuf[j] = '\0';
 #else /* SQUELCH defined */
-    hexbuf[0] = '\0';
+    scbuf[0] = '\0';
 #endif /* SQUELCH_ENABLE */
-    return hexbuf;
+    return scbuf;
 }
+/*@+mustdefine@*/
 
 /*@ +charint -shiftimplementation @*/
 static int hex2bin(const char *s)
-- 
cgit v1.2.1