[PATCH v6] netlink: decode libudev netlink header
Harsha Sharma
harshasharmaiitr at gmail.com
Sat Mar 3 11:11:43 UTC 2018
* defs.h (decode_netlink_kobject_uevent): New prototype.
* netlink.c (decode_netlink): Decode family kobject_uevent.
* netlink_kobject_uevent.h: New file.
* netlink_object_uevent.c: New file.
* Makefile.am (strace_SOURCES): Add them.
Signed-off-by: Harsha Sharma <harshasharmaiitr at gmail.com>
---
Changes in v6:
* Remove CMSG_ALIGN
Changes in v5:
* print filter_* fields in hex
* print messages after header in correct way
Changes in v4:
* Minor changes in decode_netlink_kobject_uevent
Changes in v3:
* Change changelog
* minor changes in decode_netlink_kobject_uevent
* omit irrelevant comments in netlink_kobject_uevent.h
Changes in v2:
* New file netlink_kobject_uevent.c
* change location of netlink_kobject_uevent.h
* add comments in netlink_kobject_uevent.h
* add new files in Makefile.am
* add func decode_netlink_kobject_uevent in defs.h
* Use macros from print_fields.h instead of tprintf
* minor changes in decode_netlink_kobject_uevent (including name)
Makefile.am | 2 ++
defs.h | 3 +++
netlink.c | 2 +-
netlink_kobject_uevent.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++
netlink_kobject_uevent.h | 17 ++++++++++++
5 files changed, 90 insertions(+), 1 deletion(-)
create mode 100644 netlink_kobject_uevent.c
create mode 100644 netlink_kobject_uevent.h
diff --git a/Makefile.am b/Makefile.am
index 3bc546d1..96423f0b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -200,6 +200,8 @@ strace_SOURCES = \
netlink.c \
netlink.h \
netlink_crypto.c \
+ netlink_kobject_uevent.c \
+ netlink_kobject_uevent.h \
netlink_sock_diag.h \
netlink_inet_diag.c \
netlink_netlink_diag.c \
diff --git a/defs.h b/defs.h
index b4170af4..63c32ca1 100644
--- a/defs.h
+++ b/defs.h
@@ -708,6 +708,9 @@ DECL_NETLINK(route);
DECL_NETLINK(selinux);
DECL_NETLINK(sock_diag);
+extern void
+decode_netlink_kobject_uevent(struct tcb *, kernel_ulong_t addr,
+ kernel_ulong_t len);
extern int tv_nz(const struct timeval *);
extern int tv_cmp(const struct timeval *, const struct timeval *);
extern double tv_float(const struct timeval *);
diff --git a/netlink.c b/netlink.c
index beb6ea4a..a714d29a 100644
--- a/netlink.c
+++ b/netlink.c
@@ -629,7 +629,7 @@ decode_netlink(struct tcb *const tcp,
const int family = get_fd_nl_family(tcp, fd);
if (family == NETLINK_KOBJECT_UEVENT) {
- printstrn(tcp, addr, len);
+ decode_netlink_kobject_uevent(tcp, addr, len);
return;
}
diff --git a/netlink_kobject_uevent.c b/netlink_kobject_uevent.c
new file mode 100644
index 00000000..e1f6c837
--- /dev/null
+++ b/netlink_kobject_uevent.c
@@ -0,0 +1,67 @@
+/*
+ * Copyright (c) 2018 Harsha Sharma <harshasharmaiitr 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"
+#include "print_fields.h"
+#include "netlink_kobject_uevent.h"
+
+#include <arpa/inet.h>
+
+void
+decode_netlink_kobject_uevent(struct tcb *tcp, kernel_ulong_t addr,
+ kernel_ulong_t len)
+{
+ struct udev_monitor_netlink_header uh;
+ const char *prefix = "libudev";
+ unsigned int offset = sizeof(uh);
+
+ if (len < offset) {
+ printstrn(tcp, addr, len);
+ } else if (!umove_or_printaddr(tcp, addr, &uh)) {
+ if (strcmp(uh.prefix, prefix) == 0) {
+ PRINT_FIELD_CSTRING("{{", uh, prefix);
+ tprintf(", magic=htonl(%#x)", ntohl(uh.magic));
+ PRINT_FIELD_U(", ", uh, header_size);
+ PRINT_FIELD_U(", ", uh, properties_off);
+ PRINT_FIELD_U(", ", uh, properties_len);
+ tprintf(", filter_subsystem_hash=htonl(%#x)", ntohl(uh.filter_subsystem_hash));
+ tprintf(", filter_devtype_hash=htonl(%#x)", ntohl(uh.filter_devtype_hash));
+ tprintf(", filter_tag_bloom_hi=htonl(%#x)", ntohl(uh.filter_tag_bloom_hi));
+ tprintf(", filter_tag_bloom_lo=htonl(%#x)", ntohl(uh.filter_tag_bloom_lo));
+ tprints("}");
+ if (len > offset) {
+ tprints(", ");
+ printstrn(tcp, addr + offset, len - offset);
+ }
+ tprints("}");
+ } else {
+ printstrn(tcp, addr, len);
+ }
+
+ }
+}
diff --git a/netlink_kobject_uevent.h b/netlink_kobject_uevent.h
new file mode 100644
index 00000000..5ac57cae
--- /dev/null
+++ b/netlink_kobject_uevent.h
@@ -0,0 +1,17 @@
+#ifndef STRACE_NETLINK_KOBJECT_UEVENT_H
+#define STRACE_NETLINK_KOBJECT_UEVENT_H
+
+struct udev_monitor_netlink_header {
+ /* "libudev" prefix to distinguish libudev and kernel messages */
+ char prefix[8];
+ unsigned int magic;
+ unsigned int header_size;
+ unsigned int properties_off;
+ unsigned int properties_len;
+ unsigned int filter_subsystem_hash;
+ unsigned int filter_devtype_hash;
+ unsigned int filter_tag_bloom_hi;
+ unsigned int filter_tag_bloom_lo;
+};
+
+#endif /* !STRACE_NETLINK_KOBJECT_UEVENT_H */
--
2.14.1
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