Merge pull request #361 from nuclearcat/fix-protocol-buffer-access

Fix several unsafe or unaligned integer accesses found in protocol parsing paths, including option-gated MPPE, DHCP, PPPoE, RADIUS, IPCP and IPv6CP code.

1 files changed, 73 insertions, 0 deletions

diff --git a/accel-pppd/utils.h b/accel-pppd/utils.h
index 63c1db0d..7c62422c 100644
--- a/accel-pppd/utils.h
+++ b/accel-pppd/utils.h
@@ -1,13 +1,86 @@
 #ifndef __UTILS_H
 #define __UTILS_H
 
+#include <endian.h>
 #include <netinet/in.h>
 #include <stdint.h>
+#include <string.h>
 
 #ifndef min
 #define min(x, y) ((x) < (y) ? (x) : (y))
 #endif
 
+/*
+ * Fixed-size memcpy() lets the compiler emit efficient unaligned accesses on
+ * architectures that support them without imposing alignment or aliasing
+ * requirements on callers.
+ */
+static inline uint16_t u_read_be16(const void *ptr)
+{
+	uint16_t value;
+
+	memcpy(&value, ptr, sizeof(value));
+	return ntohs(value);
+}
+
+static inline uint32_t u_read_be32(const void *ptr)
+{
+	uint32_t value;
+
+	memcpy(&value, ptr, sizeof(value));
+	return ntohl(value);
+}
+
+static inline uint64_t u_read_be64(const void *ptr)
+{
+	uint64_t value;
+
+	memcpy(&value, ptr, sizeof(value));
+	return be64toh(value);
+}
+
+static inline void u_write_be16(void *ptr, uint16_t value)
+{
+	value = htons(value);
+	memcpy(ptr, &value, sizeof(value));
+}
+
+static inline void u_write_be32(void *ptr, uint32_t value)
+{
+	value = htonl(value);
+	memcpy(ptr, &value, sizeof(value));
+}
+
+static inline void u_write_be64(void *ptr, uint64_t value)
+{
+	value = htobe64(value);
+	memcpy(ptr, &value, sizeof(value));
+}
+
+static inline uint16_t u_read_native16(const void *ptr)
+{
+	uint16_t value;
+
+	memcpy(&value, ptr, sizeof(value));
+	return value;
+}
+
+static inline uint32_t u_read_native32(const void *ptr)
+{
+	uint32_t value;
+
+	memcpy(&value, ptr, sizeof(value));
+	return value;
+}
+
+static inline uint64_t u_read_native64(const void *ptr)
+{
+	uint64_t value;
+
+	memcpy(&value, ptr, sizeof(value));
+	return value;
+}
+
 char *u_ip6str(const struct in6_addr *addr, char *buf);
 char *u_ip4str(const struct in_addr *addr, char *buf);