[PATCH v2 13/16] netlink: introduce nla_decoder_t to parse netlink attribute data
JingPiao Chen
chenjingpiao at gmail.com
Sun Jun 18 05:18:40 UTC 2017
* defs.h (decode_nlattr): Move ...
* nlattr.h: ... here, new file.
(decode_nlattr): Add decoders, size and opaque_data argument.
* Makefile.am (strace_SOURCES): Add it.
* nlattr.c: Include "nlattr.h".
(decode_nla_*): New functions.
(decode_nlattr_with_data): Add decoders, size and opaque_data argument.
* netlink_sock_diag.c (decode_inet_diag_req_compat)
(decode_inet_diag_req_v2, decode_inet_diag_msg)
(decode_netlink_diag_msg, (decode_packet_diag_msg)
(decode_smc_diag_msg, decode_unix_diag_msg): Add decoders,
size and opaque_data arguments.
Co-authored-by: Fabien Siron <fabien.siron at epita.fr>
---
Makefile.am | 1 +
defs.h | 3 ---
netlink_sock_diag.c | 22 +++++++++++++------
nlattr.c | 63 +++++++++++++++++++++++++++++++++++++++++++++++++----
nlattr.h | 55 ++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 130 insertions(+), 14 deletions(-)
create mode 100644 nlattr.h
diff --git a/Makefile.am b/Makefile.am
index 132b5e1..a25e41d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -174,6 +174,7 @@ strace_SOURCES = \
netlink.c \
netlink_sock_diag.c \
nlattr.c \
+ nlattr.h \
nsfs.c \
nsfs.h \
nsig.h \
diff --git a/defs.h b/defs.h
index 19653f3..487e51b 100644
--- a/defs.h
+++ b/defs.h
@@ -632,9 +632,6 @@ tprint_iov_upto(struct tcb *, kernel_ulong_t len, kernel_ulong_t addr,
extern void
decode_netlink(struct tcb *, int fd, kernel_ulong_t addr, kernel_ulong_t len);
-extern void
-decode_nlattr(struct tcb *, kernel_ulong_t addr, kernel_ulong_t len,
- const struct xlat *, const char *);
extern void tprint_open_modes(unsigned int);
extern const char *sprint_open_modes(unsigned int);
diff --git a/netlink_sock_diag.c b/netlink_sock_diag.c
index f0e2f30..1443995 100644
--- a/netlink_sock_diag.c
+++ b/netlink_sock_diag.c
@@ -28,6 +28,7 @@
*/
#include "defs.h"
+#include "nlattr.h"
#include <sys/socket.h>
#include <arpa/inet.h>
@@ -146,7 +147,8 @@ decode_unix_diag_msg(struct tcb *const tcp,
tprints(", ");
decode_nlattr(tcp, addr + NLA_ALIGN(sizeof(msg)),
len - NLA_ALIGN(sizeof(msg)),
- unix_diag_attrs, "UNIX_DIAG_???");
+ unix_diag_attrs, "UNIX_DIAG_???",
+ NULL, 0, NULL);
}
}
@@ -233,7 +235,8 @@ decode_netlink_diag_msg(struct tcb *const tcp,
tprints(", ");
decode_nlattr(tcp, addr + NLA_ALIGN(sizeof(msg)),
len - NLA_ALIGN(sizeof(msg)),
- netlink_diag_attrs, "NETLINK_DIAG_???");
+ netlink_diag_attrs, "NETLINK_DIAG_???",
+ NULL, 0, NULL);
}
}
@@ -302,7 +305,8 @@ decode_packet_diag_msg(struct tcb *const tcp,
tprints(", ");
decode_nlattr(tcp, addr + NLA_ALIGN(sizeof(msg)),
len - NLA_ALIGN(sizeof(msg)),
- packet_diag_attrs, "PACKET_DIAG_???");
+ packet_diag_attrs, "PACKET_DIAG_???",
+ NULL, 0, NULL);
}
}
@@ -364,7 +368,8 @@ decode_inet_diag_req_compat(struct tcb *const tcp,
tprints(", ");
decode_nlattr(tcp, addr + NLA_ALIGN(sizeof(req)),
len - NLA_ALIGN(sizeof(req)),
- inet_diag_req_attrs, "INET_DIAG_REQ_???");
+ inet_diag_req_attrs, "INET_DIAG_REQ_???",
+ NULL, 0, NULL);
}
}
@@ -406,7 +411,8 @@ decode_inet_diag_req_v2(struct tcb *const tcp,
tprints(", ");
decode_nlattr(tcp, addr + NLA_ALIGN(sizeof(req)),
len - NLA_ALIGN(sizeof(req)),
- inet_diag_req_attrs, "INET_DIAG_REQ_???");
+ inet_diag_req_attrs, "INET_DIAG_REQ_???",
+ NULL, 0, NULL);
}
}
@@ -470,7 +476,8 @@ decode_inet_diag_msg(struct tcb *const tcp,
tprints(", ");
decode_nlattr(tcp, addr + NLA_ALIGN(sizeof(msg)),
len - NLA_ALIGN(sizeof(msg)),
- inet_diag_attrs, "INET_DIAG_???");
+ inet_diag_attrs, "INET_DIAG_???",
+ NULL, 0, NULL);
}
}
@@ -548,7 +555,8 @@ decode_smc_diag_msg(struct tcb *const tcp,
tprints(", ");
decode_nlattr(tcp, addr + NLA_ALIGN(sizeof(msg)),
len - NLA_ALIGN(sizeof(msg)),
- smc_diag_attrs, "SMC_DIAG_???");
+ smc_diag_attrs, "SMC_DIAG_???",
+ NULL, 0, NULL);
}
}
#endif
diff --git a/nlattr.c b/nlattr.c
index 827f109..982e422 100644
--- a/nlattr.c
+++ b/nlattr.c
@@ -28,6 +28,7 @@
*/
#include "defs.h"
+#include "nlattr.h"
#include <linux/netlink.h>
@@ -66,7 +67,10 @@ decode_nlattr_with_data(struct tcb *tcp,
kernel_ulong_t addr,
kernel_ulong_t len,
const struct xlat *const table,
- const char *const dflt)
+ const char *const dflt,
+ nla_decoder_t *decoders,
+ const unsigned int size,
+ void *const opaque_data)
{
tprints("{");
@@ -76,7 +80,13 @@ decode_nlattr_with_data(struct tcb *tcp,
if (nla_len > NLA_HDRLEN) {
tprints(", ");
- printstrn(tcp, addr + NLA_HDRLEN, nla_len - NLA_HDRLEN);
+ if (!decoders
+ || nla->nla_type >= size
+ || !decoders[nla->nla_type]
+ || !decoders[nla->nla_type](tcp, addr + NLA_HDRLEN,
+ nla_len - NLA_HDRLEN,
+ opaque_data))
+ printstrn(tcp, addr + NLA_HDRLEN, len - NLA_HDRLEN);
}
tprints("}");
@@ -87,7 +97,10 @@ decode_nlattr(struct tcb *const tcp,
kernel_ulong_t addr,
kernel_ulong_t len,
const struct xlat *const table,
- const char *const dflt)
+ const char *const dflt,
+ nla_decoder_t *decoders,
+ const unsigned int size,
+ void *const opaque_data)
{
struct nlattr nla;
bool print_array = false;
@@ -115,7 +128,8 @@ decode_nlattr(struct tcb *const tcp,
print_array = true;
}
- decode_nlattr_with_data(tcp, &nla, addr, len, table, dflt);
+ decode_nlattr_with_data(tcp, &nla, addr, len, table, dflt,
+ decoders, size, opaque_data);
if (!next_addr)
break;
@@ -129,3 +143,44 @@ decode_nlattr(struct tcb *const tcp,
tprints("]");
}
}
+
+bool
+decode_nla_str(struct tcb *tcp, kernel_ulong_t addr,
+ kernel_ulong_t len, void *const opaque_data)
+{
+ printstr(tcp, addr);
+
+ return true;
+}
+
+bool
+decode_nla_strn(struct tcb *tcp, kernel_ulong_t addr,
+ kernel_ulong_t len, void *const opaque_data)
+{
+ printstrn(tcp, addr, len);
+
+ return true;
+}
+
+#define DECODE_NLA_INTEGER(name, type, fmt) \
+bool \
+decode_nla_ ## name(struct tcb *tcp, kernel_ulong_t addr, \
+ kernel_ulong_t len, void *const opaque_data) \
+{ \
+ type num; \
+ \
+ if (len < sizeof(num)) \
+ printstr_ex(tcp, addr, len, QUOTE_FORCE_HEX); \
+ else if (!umove_or_printaddr(tcp, addr, &num)) \
+ tprintf(fmt, num); \
+ return true; \
+}
+
+DECODE_NLA_INTEGER(u8, uint8_t, "%" PRIu8)
+DECODE_NLA_INTEGER(u16, uint16_t, "%" PRIu16)
+DECODE_NLA_INTEGER(u32, uint32_t, "%" PRIu32)
+DECODE_NLA_INTEGER(u64, uint64_t, "%" PRIu64)
+DECODE_NLA_INTEGER(s8, int8_t, "%" PRId8)
+DECODE_NLA_INTEGER(s16, int16_t, "%" PRId16)
+DECODE_NLA_INTEGER(s32, int32_t, "%" PRId32)
+DECODE_NLA_INTEGER(s64, int64_t, "%" PRId64)
diff --git a/nlattr.h b/nlattr.h
new file mode 100644
index 0000000..edae56b
--- /dev/null
+++ b/nlattr.h
@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2016 Fabien Siron <fabien.siron at epita.fr>
+ * Copyright (c) 2017 JingPiao Chen <chenjingpiao at gmail.com>
+ * Copyright (c) 2016-2017 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.
+ */
+
+typedef bool (*nla_decoder_t)(struct tcb *, kernel_ulong_t addr,
+ kernel_ulong_t len, void *opaque_data);
+extern void
+decode_nlattr(struct tcb *,
+ kernel_ulong_t addr,
+ kernel_ulong_t len,
+ const struct xlat *,
+ const char *dflt,
+ nla_decoder_t *,
+ const unsigned int size,
+ void *opaque_data);
+
+#define DECL_NLA(name) \
+extern bool \
+decode_nla_ ## name(struct tcb *, kernel_ulong_t addr, \
+ kernel_ulong_t len, void *)
+DECL_NLA(u8);
+DECL_NLA(u16);
+DECL_NLA(u32);
+DECL_NLA(u64);
+DECL_NLA(s8);
+DECL_NLA(s16);
+DECL_NLA(s32);
+DECL_NLA(s64);
+DECL_NLA(str);
+DECL_NLA(strn);
--
2.7.4
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