netlink: introduce a basic netlink attributes parser

* linux/unix_diag.h (UNIX_DIAG_*): New enum.
* nlattr.c: New file.
* nlattr.h: Likewise.
* Makefile.am (strace_SOURCES): Add them.
* netlink_sock_diag.c: Include "nlattr.h" and "xlat/unix_diag_attrs.h".
(decode_unix_diag_msg): Use decode_nlattr.
* xlat/unix_diag_attrs.in: New file.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: introduce netlink.h

* netlink.h: New file.
* Makefile.am (strace_SOURCES): Add it.
* netlink_sock_diag.c: Include "netlink.h",
remove <sys/socket.h> and <linux/netlink.h>.
* netlink.c: Likewise.
(NLMSG_HDRLEN): Move to netlink.h.
* tests/netlink_protocol.c: Replace <linux/netlink.h> with "netlink.h".
* tests/netlink_sock_diag.c: Likewise.

tests: add SET_STRUCT macro to tests.h

* tests/netlink_sock_diag.c (INIT_STRUCT): Rename to SET_STRUCT,
all callers updated.  Move ...
* tests/tests.h: ... here.

tests: fix potential unaligned access in netlink_sock_diag.test

Despite our efforts made to avoid unaligned access, gcc appears to be
generating instructions that might cause unaligned access when copying
structures to unaligned addresses.

Fix this issue by replacing copying of structures to unaligned addresses
with memcpy calls.

* tests/netlink_sock_diag.c (INIT_STRUCT): New macro.
(test_odd_family_req, test_odd_family_msg, test_unix_diag_req,
test_unix_diag_msg, test_netlink_diag_req, test_netlink_diag_msg,
test_packet_diag_req, test_packet_diag_msg, test_inet_diag_sockid,
test_inet_diag_req, test_inet_diag_req_v2, test_inet_diag_msg,
test_smc_diag_req, test_smc_diag_msg): Use it to initialize potentially
unaligned struct nlmsghdr.  Do not access nlh->nlmsg_len.

tests: check decoding of NETLINK_GENERIC message types

* tests/netlink_generic.c: New file.
* tests/gen_tests.in (netlink_generic): New entry.
* tests/pure_executables.list: Add netlink_generic.
* tests/.gitignore: Likewise.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

netlink: add decoding of NETLINK_GENERIC protocol families

NETLINK_GENERIC is a protocol stacked on netlink protocol.

When a NETLINK_GENERIC subsystem registers its "family" name in the
kernel at run time, an integer value associated with this name is
assigned by the kernel.  This integer value is specified in struct
nlmsghdr.nlmsg_type of subsequent communications with the
NETLINK_GENERIC subsystem.

This change implements decoding of NETLINK_GENERIC message types in
symbolic form, for example:

  $ ./strace -yy -e 'sendto' ip tcp_metrics > /dev/null
  sendto(4<NETLINK:[GENERIC:12345]>, {{len=20, type=tcp_metrics, ...
  +++ exited with 0 +++

Note that type= specifying the NETLINK_GENERIC protocol family
is decoded properly.

* netlink.c (decode_nlmsg_type_generic): New function.
(nlmsg_types): Add NETLINK_GENERIC entry.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

socketutils: build a dynamic xlat table for NETLINK_GENERIC decoding

* configure.ac (AC_CHECK_HEADERS): Add linux/genetlink.h.
* defs.h (genl_families_xlat): New prototype.
* socketutils.c [HAVE_LINUX_GENETLINK_H]: Include <linux/genetlink.h>.
[HAVE_LINUX_GENETLINK_H] (genl_send_dump_families,
genl_parse_families_response): New helper functions.
(genl_families_xlat): New function for building the xlat table
for NETLINK_GENERIC decoding.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

dyxlat: new interface for building xlat tables dynamically

xlat tables are usually generated at build time.

printxval is suitable for printing struct nlmsghdr.nlmsg_type for
NETLINK_GENERIC protocol.  However, the corresponding xlat table
cannot be defined at build time because the values are registered
by the kernel at run time.

This change introduces dyxlat functions for building xlat tables
dynamically.  The primary use case is decoding nlmsg_type but this
interface can be used for other purposes.

* defs.h (struct dyxlat): New opaque data type.
(dyxlat_alloc, dyxlat_free, dyxlat_add_pair): New function declarations.
* dyxlat.c: New file.
* Makefile.am (strace_SOURCES): Add it.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

Introduce xstrndup function

* configure.ac (AC_CHECK_FUNCS): Add strndup.
* defs.h (xstrndup): New prototype.
* xmalloc.c (xstrndup): New function.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

netlink: do not print extra braces around payloadless nlmsghdr

* netlink.c (decode_nlmsghdr_with_payload): Print braces before
print_nlmsghdr and after decode_payload iff decode_payload is invoked.
* tests/netlink_audit.c (test_nlmsg_type): Update expected output.
* tests/netlink_netfilter.c: Likewise.
* tests/netlink_selinux.c: Likewise.
* tests/netlink_protocol.c (send_query): Likewise.
* tests/netlink_route.c (test_nlmsg_type, test_nlmsg_flags): Likewise.
* tests/netlink_sock_diag.c: Likewise.
* tests/netlink_xfrm.c: Likewise.

Strip argument name of type "struct tcb *" from function prototypes

"struct tcb *" was used in most prototypes along with "struct tcb *tcp",
this change converts the latter form to the former for consistency.

Fix a few spacing style issues

Reported by kernel's checkpatch.pl script.

Strip redundant trailing semicolons

Strip trailing semicolons from macro definitions.
Strip extra semicolons from statements terminations.

Reported by kernel's checkpatch.pl script.

Fix macros encosure in a do/while loop

Enclose macros with multiple statements and macros starting
with "if" statement in a do/while loop.
Do not enclose single statement macros in a do/while loop.

Reported by kernel's checkpatch.pl script.

Use __func__ instead of gcc specific __FUNCTION__

Reported by kernel's checkpatch.pl script.

Fix a few initialization style issues

Do not initialise statics and globals to 0, NULL, or false.

Reported by kernel's checkpatch.pl script.

Fix function prototypes with unspecified arguments

Change functions declared as taking unspecified number of arguments
of unspecified type to functions that take no arguments.

Reported by kernel's checkpatch.pl script.

Fix a few sizeof style issues

Reported by kernel's checkpatch.pl script.

Fix a few misspellings in comments

Reported by kernel's checkpatch.pl script.

print_mreq: remove superfluous print_quoted_string calls

The string returned by inet_ntoa(3) has IPv4 dotted-decimal notation,
no need to quote it.

* net.c (print_mreq): Remove print_quoted_string calls.

tests: check decoding of incomplete SCM_TIMESTAMP* control messages

* tests/msg_control.c (test_scm_timestamp, test_scm_timestampns,
test_scm_timestamping): Check decoding of incomplete control messages.

msghdr: print SCM_TIMESTAMP* control messages

Add support for printing control messages containing software and/or
hardware timestamps, which are typically enabled by NTP and PTP
implementations.

* print_timeval.c (print_struct_timeval_data_size): New mpers printer.
* print_timespec.c (print_struct_timespec_data_size,
print_struct_timespec_array_data_size): Likewise.
* msghdr.c (print_scm_timestamp, print_scm_timestampns,
print_scm_timestamping): New functions.
(cmsg_socket_printers): Add them.
* NEWS: Mention this change.
* tests/msg_control.c: Include "xlat.h" and "xlat/scmvals.h".
(test_scm_timestamp, test_scm_timestampns, test_scm_timestamping):
New functions.
(test_sol_socket): Use them.

Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

tests: check decoding of NETLINK_SOCK_DIAG AF_SMC messages

* tests/netlink_sock_diag.c: Include <linux/smc_diag.h>.
(SMC_ACTIVE): New macro.
(test_smc_diag_req, test_smc_diag_msg): New functions.
(main): Use them.

netlink: add a basic socket diag parser of AF_SMC messages

* linux/smc_diag.h: New file.
* Makefile.am (EXTRA_DIST): Add it.
* netlink_sock_diag.c: Include <linux/smc_diag.h>,
"xlat/smc_diag_extended_flags.h" and "xlat/smc_states.h".
(decode_smc_diag_req, decode_smc_diag_msg): New functions.
(diag_decoders): Add AF_SMC.
* xlat/smc_diag_extended_flags.in: New file.
* xlat/smc_states.in: Likewise.

tests: check decoding of NETLINK_SOCK_DIAG AF_INET messages

* tests/netlink_sock_diag.c: Include <arpa/inet.h>
and <linux/inet_diag.h>.
(test_inet_diag_sockid, test_inet_diag_req, test_inet_diag_req_v2,
test_inet_diag_msg): New functions.
(mian): Use them.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: add a basic socket diag parser of AF_INET and AF_INET6 messages

* defs.h (inet_protocols): New xlat prototype.
* linux/inet_diag.h (inet_diag_req): New structure.
(INET_DIAG_*): New enum.
* netlink_sock_diag.c: Include <arpa/inet.h>, <linux/inet_diag.h>
and "xlat/inet_diag_extended_flags.h".
(print_inet_diag_sockid, decode_inet_diag_req_compat)
(decode_inet_diag_req_v2, decode_inet_diag_req)
(decode_inet_diag_msg): New functions.
(diag_decoders): Add AF_INET and AF_INET6;
* xlat/inet_diag_extended_flags.in: New file.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

Introduce print_inet_addr

* defs.h (print_inet_addr): New prototype.
* sockaddr.c (print_inet_addr): New function.
(print_sockaddr_data_in6): Use it.
* net.c (print_mreq6): Likewise.
* tests/ip_mreq.c (main): Update expected output.

tests: check decoding of NETLINK_SOCK_DIAG AF_PACKET messages

* tests/netlink_sock_diag.c: Include <linux/if_ether.h>
and <linux/packet_diag.h>.
(test_packet_diag_req, test_packet_diag_msg): New functions.
(main): Use them.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: add a basic socket diag parser of AF_PACKET messages

* linux/packet_diag.h: New file.
* Makefile.am (EXTRA_DIST): Add it.
* defs.h (ethernet_protocols): New xlat prototype.
* netlink_sock_diag.c: Include <linux/packet_diag.h>
and "xlat/packet_diag_show.h".
(decode_packet_diag_req, decode_packet_diag_msg): New functions.
(diag_decoders): Add AF_PACKET.
* xlat/packet_diag_show.in: New file.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

tests: check decoding of NETLINK_SOCK_DIAG AF_NETLINK messages

* tests/netlink_sock_diag.c: Include <linux/netlink_diag.h>.
(test_netlink_diag_req, test_netlink_diag_msg): New functions.
(main): Use them.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: add a basic socket diag parser of AF_NETLINK messages

* linux/netlink_diag.h (NDIAG_SHOW_GROUPS, NDIAG_SHOW_RING_CFG):
New macros.
* netlink_sock_diag.c: Include <linux/netlink_diag.h>,
"xlat/netlink_diag_show.h" and "xlat/netlink_states.h".
(decode_netlink_diag_req, decode_netlink_diag_msg): New functions.
(diag_decoders): Add AF_NETLINK.
* xlat/netlink_diag_show.in: New file.
* xlat/netlink_states.in: Likewise.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

tests: check decoding of NETLINK_SOCK_DIAG AF_UNIX messages

* tests/netlink_sock_diag.c: Include <netinet/tcp.h>
and <linux/unix_diag.h>.
(test_odd_family_req, test_odd_family_msg, test_unix_diag_req,
test_unix_diag_msg): New functions.
(main): Use them.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>
Co-authored-by: JingPiao Chen <chenjingpiao@gmail.com>

netlink: add a basic socket diag parser of AF_UNIX messages

* defs.h (socktypes): New xlat prototype.
* linux/unix_diag.h (UDIAG_SHOW_VFS, UDIAG_SHOW_ICONS, UDIAG_SHOW_RQLEN,
UDIAG_SHOW_MEMINFO): New macros.
* netlink_sock_diag.c: Include <sys/socket.h>, <linux/netlink.h>,
<linux/unix_diag.h>, "xlat/tcp_states.h", "xlat/tcp_state_flags.h",
and "xlat/unix_diag_show.h".
(decode_unix_diag_req, decode_unix_diag_msg): New functions.
(netlink_diag_decoder_t): New typedef.
(diag_decoders): New array.
(decode_netlink_sock_diag): Use it.
* xlat/tcp_state_flags.in: New file.
* xlat/tcp_states.in: Likewise.
* xlat/unix_diag_show.in: Likewise.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>
Co-authored-by: JingPiao Chen <chenjingpiao@gmail.com>

netlink: introduce family specific payload decoders

* defs.h (netlink_decoder_t): New typedef.
(DECL_NETLINK): New macro.
(decode_netlink_sock_diag): New prototype.
* netlink.c (netlink_decoders): New array.
(decode_payload): Use it to invoke netlink family specific decoders.
* netlink_sock_diag.c: New file.
* Makefile.am (strace_SOURCES): Add it.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>
Co-authored-by: JingPiao Chen <chenjingpiao@gmail.com>

Update SCM_* constants

* xlat/scmvals.in: Add SCM_TIMESTAMP, SCM_TIMESTAMPNS, SCM_TIMESTAMPING,
SCM_WIFI_STATUS, and SCM_TIMESTAMPING_OPT_STATS.

netlink: refactor decode_nlmsg_type

* netlink.c (decode_nlmsg_type_default, decode_nlmsg_type_netfilter):
New functions.
(nlmsg_types_decoder_t): New typedef.
(nlmsg_types): Add decoder field.
(decode_nlmsg_type): Use it.

tests: extend printstr test

* tests/printstr.c (main): Add a case for short read.

v4l2: fix preprocessor checks

Fix checks for struct v4l2_window.global_alpha and struct
v4l2_sdr_format.buffersize.

* v4l2.c (print_v4l2_format_fmt): Do not assume that
HAVE_STRUCT_V4L2_WINDOW_GLOBAL_ALPHA and
HAVE_STRUCT_V4L2_SDR_FORMAT_BUFFERSIZE are defined.
* tests/ioctl_v4l2.c (init_v4l2_format, dprint_ioctl_v4l2): Likewise.

Move xlat related functions to a separate file

* util.c (xlookup, xlat_bsearch_compare, xlat_search, printxvals,
printxval_searchn, addflags, sprintflags, printflags_ex): Move ...
* xlat.c: ... to this new file.
* Makefile.am (strace_SOURCES): Add it.

socketeutils: extend receive_responses further

This is the second patch in series of implementing NETLINK_GENERIC
protocol decoder.

This change allows passing of opaque user data to the callback function.

* socketutils.c (receive_responses): Change the type of proto_name
argument from "const char *" to "void *" to allow passing
of arbitrary data to the callback function.
Rename proto_name to opaque_data, make it the last argument.
Pass it to the callback function as the last argument.
(inet_parse_response, unix_parse_response, netlink_parse_response):
Change the type of proto_name argument from "const char *" to "void *",
rename it to opaque_data, make it the last argument.
Introduce a local variable proto_name to convert the type
of opaque_data argument from "void *" to "const char *".
(unix_get, inet_get, netlink_get): Cast the protocol name from
"const char *" to "void *" for passing to the callback function.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

socketeutils: extend receive_responses to handle other netlink types

This is the first patch in series of implementing NETLINK_GENERIC
protocol decoder.

receive_responses was written for decoding kernel responses of type
SOCK_DIAG_BY_FAMILY, other types were ignored.

This change makes the type of netlink response a parameter
so the function can be used for other types of communication.

* socketutils.c (receive_responses): add a new parameter
expected_msg_type to handle types other than SOCK_DIAG_BY_FAMILY.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

tests: fix typo

* tests/dup3.c (SKIP_MAIN_UNDEFINED): Remove duplicated &&.

Introduce printflags_ex function

Add printflags_ex extension over printflags64 that, similar
to printxvals, takes a NULL-terminated sequence of xlat pointers.

* defs.h (printflags_ex): New prototype.
(printflags64): Turn into a thin wrapper around printflags_ex.
* netlink.c (decode_nlmsg_flags): Use printflags_ex.
* util.c (printflags_ex): New function.
(printflags64): Remove.
* xlat/netlink_get_flags.in: Remove entries listed
in xlat/netlink_flags.in file.
* xlat/netlink_new_flags.in: Likewise.

tests: add check for decoding netlink get and new flags

* tests/netlink_route.c (test_nlmsg_flags): New function, checks
decoding of NETLINK_ROUTE get and new flags.
(main): Use it.
* tests/netlink_sock_diag.c (test_nlmsg_flags): New function, checks
decoding of NETLINK_SOCK_DIAG get flags.
(main): Use it.
* tests/netlink_xfrm.c: (test_nlmsg_flags): New function, checks
decoding of NETLINK_XFRM get and new flags.
(main): Use it.

netlink: implement generic nlmsg_flags decoding

* netlink.c: Include "xlat/netlink_get_flags.h"
and "xlat/netlink_new_flags.h".
(decode_nlmsg_flags): New function.
(print_nlmsghdr): Use it.
* xlat/netlink_get_flags.in: New file.
* xlat/netlink_new_flags.in: Likewise.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>
Co-authored-by: Dmitry V. Levin <ldv@altlinux.org>

xlat: provide fallback definitions for XFRM_MSG_* constants

Some of XFRM_MSG_* constants were introduced later than the header file
where they are defined.

* xlat/nl_xfrm_types.in: Add default values for constants.

syscall.c: split trace_syscall() into 6 functions

This change removes the trace_syscall function.  Now, the code that uses
syscall.c trace functions is expected to check whether it is a syscall
entry or exit (with entering(tcp)/exiting(tcp)) itself, and then make
an appropriate sequence of function calls.

* defs.h: Update comment on TCB_INSYSCALL.
(trace_syscall): Remove prototype.
(syscall_entering_decode, syscall_entering_trace,
syscall_entering_finish, syscall_exiting_decode, syscall_exiting_trace,
syscall_exiting_finish): New prototypes.
* strace.c (trace_syscall): New static replacement for old trace_syscall.
* syscall.c (trace_syscall): Remove.
(trace_syscall_entering): Split into ...
(syscall_entering_decode, syscall_entering_trace,
syscall_entering_finish): ... new functions.
(trace_syscall_exiting): Split into ...
(syscall_exiting_decode, syscall_exiting_trace,
syscall_exiting_finish): ... new functions.

tests: guard against missing linux/netfilter/nfnetlink.h

nfnetlink was introduced in linux by commit v2.6.14-rc1~1035^2~217,
add a guard for the case when system headers are not fresh enough.

* configure.ac (AC_CHECK_HEADERS): Add linux/netfilter/nfnetlink.h.
* tests/netlink_netfilter.c: Check for HAVE_LINUX_NETFILTER_NFNETLINK_H.

tests: check decoding of NETLINK_XFRM message types

* tests/netlink_xfrm.c: New file.
* tests/gen_tests.in (netlink_xfrm): New entry.
* tests/pure_executables.list: Add netlink_xfrm.
* tests/.gitignore: Likewise.

tests: check decoding of NETLINK_SELINUX message types

* tests/netlink_selinux.c: New file.
* tests/gen_tests.in (netlink_selinux): New entry.
* tests/pure_executables.list: Add netlink_selinux.
* tests/.gitignore: Likewise.

tests: check decoding of NETLINK_NETFILTER message types

* tests/netlink_netfilter.c: New file.
* tests/gen_tests.in (netlink_netfilter): New entry.
* tests/pure_executables.list: Add netlink_netfilter.
* tests/.gitignore: Likewise.

tests: check decoding of NETLINK_AUDIT message types

* tests/netlink_audit.c: New file.
* tests/gen_tests.in (netlink_audit): New entry.
* tests/pure_executables.list: Add netlink_audit.
* tests/.gitignore: Likewise.

tests: check decoding of NETLINK_ROUTE message types

* tests/netlink_route.c: New file.
* tests/gen_tests.in (netlink_route): New entry.
* tests/pure_executables.list: Add netlink_route.
* tests/.gitignore: Likewise.

tests: check decoding of NETLINK_SOCK_DIAG message types

* tests/netlink_sock_diag.c: New file.
* tests/netlink_sock_diag.test: New test.
* tests/pure_executables.list: Add netlink_sock_diag.
* tests/.gitignore: Likewise.
* tests/Makefile.am (DECODER_TESTS): Add netlink_sock_diag.test.

tests: use create_nl_socket in netlink_protocol.test

* tests/netlink_protocol.c (main): Use create_nl_socket.

tests: change netlink_protocol.test to trace sendto syscalls only

* tests/gen_tests.in (netlink_protocol): Replace %network with sendto.
* tests/netlink_protocol.c (main): Update expected output.

tests: enhance create_nl_socket diagnostics messages

* tests/tests.h (create_nl_socket): Rename to create_nl_socket_ext,
add a string argument.
(create_nl_socket): New macro wrapper around create_nl_socket_ext.
* tests/create_nl_socket.c (create_nl_socket): Rename
to create_nl_socket_ext, add a string argument, include it
in diagnostic messages.

tests: use const and designated initializers in create_nl_socket.c

* tests/create_nl_socket.c: Stop including <string.h>.
(create_nl_socket): Use const and designated initializers.

tests: add create_nl_socket function to libtests

* tests/create_nl_socket.c: New file.
* tests/tests.h (create_nl_socket): New prototype.
* tests/Makefile.am (libtests_a_SOURCES): Add create_nl_socket.c.

netlink: add decoding of NETLINK_NETFILTER message types

* xlat/nl_netfilter_msg_types.in: New file.
* xlat/nl_netfilter_subsys_ids.in: Likewise.
* netlink.c: Include "xlat/nl_netfilter_msg_types.h"
and "xlat/nl_netfilter_subsys_ids.h".
(nlmsg_types): Add NETLINK_NETFILTER.
(decode_nlmsg_type): Handle NETLINK_NETFILTER.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: add decoding of NETLINK_XFRM message types

* xlat/nl_xfrm_types.in: New file.
* netlink.c: Include "xlat/nl_xfrm_types.h".
(nlmsg_types): Add NETLINK_XFRM.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: add decoding of NETLINK_SELINUX message types

* xlat/nl_selinux_types.in: New file.
* netlink.c: Include "xlat/nl_selinux_types.h".
(nlmsg_types): Add NETLINK_SELINUX.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: add decoding of NETLINK_ROUTE message types

* xlat/nl_route_types.in: New file.
* netlink.c: Include <linux/rtnetlink.h> and "xlat/nl_route_types.h".
(nlmsg_types): Add NETLINK_ROUTE.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: add decoding of NETLINK_AUDIT message types

* xlat/nl_audit_types.in: New file.
* netlink.c: Include <linux/audit.h> and "xlat/nl_audit_types.h".
(nlmsg_types): Add NETLINK_AUDIT.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: implement generic nlmsg_type decoding

Implement a pluggable mechanism of nlmsg_type decoding.
Add decoding of NETLINK_SOCK_DIAG types.

* linux/sock_diag.h (SOCK_DESTROY): New macro.
* xlat/nl_sock_diag_types.in: New file.
* netlink.c: Include xlat/nl_sock_diag_types.h.
(get_fd_nl_family, decode_nlmsg_type): New functions.
(print_nlmsghdr): Use them for nlmsg_type decoding.

Co-authored-by: Fabien Siron <fabien.siron@epita.fr>

netlink: add netlink family argument to printers and decoders

* netlink.c (NL_FAMILY_ERROR, NL_FAMILY_DEFAULT): New constants.
(print_nlmsghdr): Add netlink family argument, change return type
to int, return family.
(decode_nlmsghdr_with_payload, decode_nlmsgerr, decode_payload): Add
netlink family argument.  All callers updated.

Add file descriptor argument to decode_netlink

* defs.h (decode_netlink): Add file descriptor argument.
* io.c (print_iovec): Specify file descriptor to decode_netlink.
* net.c (decode_sockbuf): Likewise.
* netlink.c (print_nlmsghdr, decode_nlmsghdr_with_payload,
decode_nlmsgerr, decode_payload, decode_nlmsghdr_with_payload,
decode_netlink): Likewise.
All callers updated.

Co-authored-by: Dmitry V. Levin <ldv@altlinux.org>

Introduce getfdinode to obtain inode from fd

* defs.h (getfdinode): New prototype.
* utils.c (getfdinode): New function.

Co-authored-by: Dmitry V. Levin <ldv@altlinux.org>

Introduce get_sockaddr_by_inode

Add a way to get socket information without printing it.

* defs.h (get_sockaddr_by_inode): New prototype.
* socketutils.c (get_sockaddr_by_inode): New function.

Co-authored-by: Dmitry V. Levin <ldv@altlinux.org>

socketutils.c: introduce get_sockaddr_by_inode_uncached

* socketutils.c (get_sockaddr_by_inode_uncached): New function.
(print_sockaddr_by_inode_uncached): Use it.

socketutils.c: use get_sockaddr_by_inode_cached

* socketutils.c (unix_print, inet_print, tcp_v4_print, tcp_v6_print,
udp_v4_print, udp_v6_print, netlink_print): Remove.
(unix_get, inet_get, tcp_v4_get, tcp_v6_get, udp_v4_get,
udp_v6_get, netlink_get): New functions.
(protocols): Update.

Co-authored-by: Dmitry V. Levin <ldv@altlinux.org>

socketutils.c: move inet_print closer to its first use

* socketutils.c (inet_print): Move right before tcp_v4_print.

socketutils.c: introduce cache_inode_details

cache_inode_details gives a way to obtain cache information without
printing it.

* socketutils.c (cache_and_print_inode_details): Rename
to cache_inode_details.  Do not print cached information.
(inet_parse_response, unix_parse_response, netlink_parse_response):
Use cache_inode_details instead of cache_and_print_inode_details.
(inet_print, unix_print, netlink_print): Call
print_sockaddr_by_inode_cached.

Co-authored-by: Dmitry V. Levin <ldv@altlinux.org>

strace.c: move termination code to a separate function

This will be needed for the pull-style API.

* strace.c (terminate): New function.
(main): Use it.

tests: avoid hitting SO_SNDBUF limit in sendfile/sendfile64 tests

Do not assume that an executable is small enough and SO_SNDBUF is large
enough so that the executable could be sendfile'ed into a socket pair.

* tests/sendfile.c (main): Create a regular file of the right size
to avoid hitting SO_SNDBUF limit.
* tests/sendfile64.c: Likewise.

Reported-by: Andreas Schwab <schwab@linux-m68k.org>

Move netlink_protocols definition from net.c to netlink.c

The side effect of #include "xlat/netlink_protocols.h" is
NETLINK_* constants properly defined in that header file.
While net.c does not use these constants itself, netlink.c
is going to need them soon.

* net.c: Move inclusion of "xlat/netlink_protocols.h" ...
* netlink.c: ... here.

travis: switch from gcc-6 to gcc-7

* .travis.yml (matrix): Change gcc-6 to gcc-7.

tests: extend checking of NLMSG_DONE decoding

* tests/netlink_protocol.c (test_nlmsg_done):  Use designated
initializers.  Check decoding of messages with non-integer payload.

netlink: decode NLMSG_DONE messages

* netlink.c (decode_payload): Decode NLMSG_DONE messages.
* tests/netlink_protocol.c (test_nlmsg_done): New function
for checking decoding of NLMSG_DONE messages.
(main): Use it.

socketutils.c: introduce get_sockaddr_by_inode_cached

* socketutils.c (get_sockaddr_by_inode_cached): New function.
(print_sockaddr_by_inode_cached): Use it.

Unexport print_sockaddr_by_inode_cached

Change print_sockaddr_by_inode to be the only function exposed,
hide print_sockaddr_by_inode_cached as a part of implementation.

* defs.h (print_sockaddr_by_inode_cached): Remove prototype.
(print_sockaddr_by_inode): Add struct tcb * and descriptor arguments.
* socketutils.c (print_sockaddr_by_inode_cached): Make static.
(print_sockaddr_by_inode): Rename to print_sockaddr_by_inode_uncached,
make static.
(print_sockaddr_by_inode): New function.
* util.c (printfd): Update to use new print_sockaddr_by_inode.

Introduce str_strip_prefix_len function and STR_STRIP_PREFIX macro

Address proliferation of string prefix check implementations.

* defs.h (str_strip_prefix_len): New inline function.
(STR_STRIP_PREFIX): New macro.
* qualify.c (strip_prefix): Remove.
(parse_inject_token): Use STR_STRIP_PREFIX instead of strip_prefix.
(qualify): Use str_strip_prefix_len.
* socketutils.c (netlink_parse_response): Likewise.
* util.c (printfd): Likewise.

netlink: move NLMSG_ERROR payload length check to nlmsgerr decoder

Move decoder specific check to the decoder.

* netlink.c (decode_payload): Move NLMSG_ERROR payload length check ...
(decode_nlmsgerr): ... here.

strace.c: handle PTRACE_EVENT_EXEC like other events

There is nothing unusual about PTRACE_EVENT_EXEC that would require
a special treatment.

* strace.c (next_event): Move PTRACE_EVENT_EXEC handling to the main
switch statement.

strace.c: remove dead code

As strace does not use WCONTINUED flag, there is no need to handle
WIFCONTINUED status.

* strace.c (print_debug_info) [WIFCONTINUED]: Remove.
(next_event): Remove redundant !WIFSTOPPED check.

strace.c: refactor trace into two functions

This change decouples waiting for next event from reacting to it.  This
makes the control flow easier to understand, and serves as a preparation
for implementing a pull-style API for LuaJIT.

* strace.c (enum trace_event): New enum.
(trace): Split into ...
(next_event, dispatch_event): ... new functions.
(main): Use them.

scno.am: include config.h before syscallent.h

This fixes generation of syscallent.i and subsequent scno.h files
on mips where syscallent.h checks macros defined in config.h.

* scno.am (syscallent.i): Add $(top_builddir)/config.h
to prerequisites, include it.
* NEWS: Mention this fix.

Reported-by: David Robins <dbrobins@i4031.net>

tests: check decoding of sigaction syscall

* tests/sigaction.c: New file.
* tests/gen_tests.in (sigaction): New entry.
* tests/pure_executables.list: Add sigaction.
* tests/.gitignore: Likewise.

tests: rename sigaction.test to rt_sigaction.test

* tests/sigaction.awk: Rename to rt_sigaction.awk.
* tests/sigaction.c: Rename to tests/rt_sigaction.c.
* tests/sigaction.test: Rename to tests/rt_sigaction.test.
* tests/.gitignore: Replace sigaction with rt_sigaction.
* tests/pure_executables.list: Likewise.
* tests/Makefile.am (DECODER_TESTS): Replace sigaction.test
with rt_sigaction.test.
(EXTRA_DIST): Replace sigaction.awk with rt_sigaction.awk.

sparc: enhance decoding of signal number argument of sigaction syscall

On sparc, unlike all other architectures, old sigaction syscall takes
a negated signal number.

* signal.c (SYS_FUNC(sigaction)) [SPARC || SPARC64]: Enhance printing
of negative signal number argument.

signal: enhance printing of old_sigaction.mask

* signal.c (decode_old_sigaction): Print old_sigaction.mask
using tprint_old_sigmask_val.

signal: limit scope of struct old_sigaction32 definition

* signal.c (struct old_sigaction32): Define only if [!current_wordsize].

signal: fix decoding of struct old_sigaction on some architectures

On alpha, struct old_sigaction.sa_flags has a 32-bit type.

On mips, only first word of old_sigaction.sa_mask is read.

On all architectures except alpha and mips that have old sigaction
syscall, struct old_sigaction has sa_restorer field that has to be
decoded.

* signal.c (struct old_sigaction) [ALPHA]: Change sa_flags type
to unsigned int, add ATTRIBUTE_PACKED.
[MIPS]: Dhrink sa_mask array to 1 element.
[!ALPHA && !MIPS]: Define sa_restorer field unconditionally.
(struct old_sigaction32): Likewise.
(decode_old_sigaction) [!current_wordsize]: Initialize sa_restorer field
from old_sigaction32.sa_restorer unconditionally.
[!ALPHA && !MIPS]: Print old_sigaction.sa_restorer if SA_RESTORER flag
is set.
* NEWS: Mention this change.

xlat: rename SA_STACK to SA_ONSTACK

SA_ONSTACK is the standard name while its alias SA_STACK is not even
defined on many platforms.

* xlat/sigact_flags.in (SA_STACK): Rename to SA_ONSTACK.

tests: check decoding of sigpending syscall

* tests/sigpending.c: New file.
* tests/gen_tests.in (sigpending): New entry.
* tests/pure_executables.list: Add sigpending.
* tests/.gitignore: Likewise.

tests: check decoding of sigprocmask syscall

* tests/sigprocmask.c: New file.
* tests/gen_tests.in (sigprocmask): New entry.
* tests/pure_executables.list: Add sigprocmask.
* tests/.gitignore: Likewise.

alpha: rename sys_sigprocmask to sys_osf_sigprocmask

Parsers of sigprocmask and osf_sigprocmask syscalls are different
anyway, so rename the function to match the syscall name.

* signal.c [ALPHA] (SYS_FUNC(sigprocmask)): Rename
to SYS_FUNC(osf_sigprocmask).
* linux/alpha/syscallent.h: Update sys_func.

Enable coverage when strace is self terminated by signal

The data collected by -fprofile-arcs during program run is saved
on program exit.  When program is terminated by signal, the data
is not saved.  However, libgcov provides an interface to dump
the data at runtime.

* m4/ax_code_coverage.m4 (AX_CODE_COVERAGE): Add -DENABLE_COVERAGE_GCOV
to CODE_COVERAGE_CPPFLAGS.
* strace.c [ENABLE_COVERAGE_GCOV] (__gcov_flush): New prototype.
(main) [ENABLE_COVERAGE_GCOV]: Call __gcov_flush() before raise()
and sigprocmask() calls that might cause program termination.

tests: check termination signal forwarding

* tests/run_expect_termsig.c: New file.
* tests/unblock_reset_raise.c: Likewise.
* tests/termsig.test: New test.
* tests/.gitignore: Add run_expect_termsig and unblock_reset_raise.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(MISC_TESTS): Add termsig.test.

Fix termination signal forwarding

When traced command is terminated by a blocked signal, unblock
that signal to ensure strace termination with the same signal.

* strace.c (main): Unblock the signal raised for strace termination.
* NEWS: Mention this change.