[PATCH v2 1/6] netlink: add a basic parser of NETLINK_CRYPTO messages

[JingPiao Chen]

* netlink_crypto.c: New file.
* Makefile.am (strace_SOURCES): Add it.
* defs.h (decode_netlink_crypto): New prototype.
* netlink.c (netlink_decoders): Add NETLINK_CRYPTO.
* NEWS: Mention this.
---
 Makefile.am      |  1 +
 NEWS             |  1 +
 defs.h           |  1 +
 netlink.c        |  3 +++
 netlink_crypto.c | 80 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 86 insertions(+)
 create mode 100644 netlink_crypto.c

diff --git a/Makefile.am b/Makefile.am
index 8411f26..5d365e2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -183,6 +183,7 @@ strace_SOURCES =	\
 	net.c		\
 	netlink.c       \
 	netlink.h	\
+	netlink_crypto.c \
 	netlink_sock_diag.h \
 	netlink_inet_diag.c \
 	netlink_netlink_diag.c \
diff --git a/NEWS b/NEWS
index 88229fb..9592753 100644
--- a/NEWS
+++ b/NEWS
@@ -18,6 +18,7 @@ Noteworthy changes in release ?.?? (????-??-??)
   * Implemented NETLINK_SELINUX protocol specific decoding.
   * Implemented decoding of netlink message ack flags.
   * Implemented decoding of nlmsgerr netlink attributes.
+  * Implemented basic protocol specific decoding of NETLINK_CRYPTO.
   * Updated lists of BPF_*, KEY_*, RWF_*, SCM_*, SO_*, and *_MAGIC constants.
   * Added decoding of arch_prctl syscall on x86.
 
diff --git a/defs.h b/defs.h
index 4048915..539afa2 100644
--- a/defs.h
+++ b/defs.h
@@ -711,6 +711,7 @@ typedef bool (*netlink_decoder_t)(struct tcb *, const struct nlmsghdr *,
 extern bool								\
 decode_netlink_ ## name(struct tcb *, const struct nlmsghdr *,		\
 			kernel_ulong_t addr, unsigned int len)
+DECL_NETLINK(crypto);
 DECL_NETLINK(selinux);
 DECL_NETLINK(sock_diag);
 
diff --git a/netlink.c b/netlink.c
index b9ad7d2..947e52d 100644
--- a/netlink.c
+++ b/netlink.c
@@ -380,6 +380,9 @@ decode_nlmsgerr(struct tcb *const tcp,
 }
 
 static const netlink_decoder_t netlink_decoders[] = {
+#ifdef HAVE_LINUX_CRYPTOUSER_H
+	[NETLINK_CRYPTO] = decode_netlink_crypto,
+#endif
 	[NETLINK_SELINUX] = decode_netlink_selinux,
 	[NETLINK_SOCK_DIAG] = decode_netlink_sock_diag
 };
diff --git a/netlink_crypto.c b/netlink_crypto.c
new file mode 100644
index 0000000..cc573ff
--- /dev/null
+++ b/netlink_crypto.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2017 JingPiao Chen <chenjingpiao at gmail.com>
+ * Copyright (c) 2017 The strace developers.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "defs.h"
+
+#ifdef HAVE_LINUX_CRYPTOUSER_H
+
+# include "netlink.h"
+# include "nlattr.h"
+# include "print_fields.h"
+
+# include <linux/cryptouser.h>
+
+static void
+decode_crypto_user_alg(struct tcb *const tcp,
+		       const kernel_ulong_t addr,
+		       const unsigned int len)
+{
+	struct crypto_user_alg alg;
+
+	if (len < sizeof(alg))
+		printstrn(tcp, addr, len);
+	else if (!umove_or_printaddr(tcp, addr, &alg)) {
+		PRINT_FIELD_CSTRING("{", alg, cru_name);
+		PRINT_FIELD_CSTRING(", ", alg, cru_driver_name);
+		PRINT_FIELD_CSTRING(", ", alg, cru_module_name);
+		PRINT_FIELD_X(", ", alg, cru_type);
+		PRINT_FIELD_X(", ", alg, cru_mask);
+		PRINT_FIELD_U(", ", alg, cru_refcnt);
+		PRINT_FIELD_X(", ", alg, cru_flags);
+		tprints("}");
+	}
+}
+
+bool
+decode_netlink_crypto(struct tcb *const tcp,
+		      const struct nlmsghdr *const nlmsghdr,
+		      const kernel_ulong_t addr,
+		      const unsigned int len)
+{
+	switch (nlmsghdr->nlmsg_type) {
+	case CRYPTO_MSG_NEWALG:
+	case CRYPTO_MSG_DELALG:
+	case CRYPTO_MSG_UPDATEALG:
+	case CRYPTO_MSG_GETALG:
+		decode_crypto_user_alg(tcp, addr, len);
+		break;
+	default:
+		return false;
+	}
+
+	return true;
+}
+
+#endif /* HAVE_LINUX_CRYPTOUSER_H */
-- 
2.7.4