Implement injection of syscalls with no side effects as an alternative to -1
* defs.h (INJECT_F_SYSCALL, INJECT_ACTION_FLAGS, TCB_TAMPERED_NO_FAIL,
syscall_tampered_nofail): New macros.
(inject_data): Add scno field.
* filter_qualify.c (struct inject_personality_data): New type.
(parse_inject_token): Add "pdata" argument, parse "syscall=" option.
(parse_inject_expression): Add "pdata" argument, forward it to
parse_inject_token.
(qualify_inject_common) <pdata>: New variable array, pass it to
parse_inject_expression, copy it into inject_vec.
* syscall.c (tamper_with_syscall_entering): Inject the specified syscall
if INJECT_F_SYSCALL is set.
(tamper_with_syscall_exiting): Update the check for a failed syscall
injection.
(get_syscall_result): Update get_error invocation.
* strace.1.in: Document new syscall injection expression.
* NEWS: Mention it.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org> Closes: https://github.com/strace/strace/issues/26
linux: set error flags in arch_set_error on POWER and Alpha
* alpha/set_error.c (arch_set_error): Set alpha_r3 to 1, update tracee's
REG_A3.
* powerpc/set_error.c (arch_set_error): Set bit 28 in CCR register,
update tracee's PT_CCR.
Fixes: v4.15~126 "Implement arch specific methods of changing syscall number and error code"
tests: add fallback_func argument to TEST_NESTED_NLATTR_OBJECT_EX_
* tests/test_nlattr.h (TEST_NESTED_NLATTR_OBJECT_EX_): Add fallback_func
argument, call it instead of print_quoted_hex.
(TEST_NESTED_NLATTR_OBJECT_EX, TEST_NESTED_NLATTR_OBJECT): Specify
print_quoted_hex as a fallback_func.
* tests/nlattr_ifla_af_spec.c: Specify print_quoted_hex as
a fallback_func in TEST_NESTED_NLATTR_OBJECT_EX_ calls.
tests/test_nlattr.h: add ability to provide additional nlattr payload
* tests/test_nlattr.h (print_nlattr): Add add_data argument, print
opening square bracket if add_data is set to true.
(TEST_NLATTR_EX_): Rename from TEST_NLATTR_, add nla_total_len_
argument, use it for msg_len calculation, print square brackets
if nla_total_len_ is greater than nla_data_len_.
(TEST_NLATTR_): New macro, a wrapper for TEST_NLATTR_EX_.
* rtnl_link.c (decode_ifla_bridge_id): Provide struct definition for
the id variable.
[!HAVE_STRUCT_IFLA_BRIDGE_ID] (decode_ifla_bridge_id): Decode struct
ifla_bridge_id.
rtnl_link: fix incorrect variable names in ARRAY_SIZE arguments
* rtnl_link.c (decode_nla_linkinfo_data_bridge): Change
rtnl_ifla_info_data_bridge_attrs to ifla_info_data_bridge_nla_decoders
in ARRAY_SIZE call.
(decode_nla_linkinfo_data_tun): Change rtnl_ifla_info_data_tun_attrs
to ifla_info_data_tun_nla_decoders in ARRAY_SIZE call.
Fixes: v4.22-328-g1e6d5a8 "rtnl_link: implement IFLA_INFO_DATA for bridges" Fixes: v4.22-329-g4eab3a4 "rtnl_link: implement IFLA_INFO_DATA for tun devices"
Dmitry V. Levin [Thu, 7 Jun 2018 14:01:24 +0000 (14:01 +0000)]
configure.ac: fix the check for struct tc_sizespec on old kernel headers
* configure.ac (AC_CHECK_TYPES): Include <linux/types.h> before
<linux/pkt_sched.h> to check for struct tc_sizespec on linux kernel
headers without v2.6.29-rc4~77^2~26 fix.
tests: add TEST_NESTED_NLATTR_ARRAY_EX to test_nlattr.h
An ability to specify custom depth is going to be needed later to check
IFLA_AF_SPEC decoding.
* configure.ac (AC_CHECK_DECLS): Check for TCA_STAB_DATA in
<linux/pkt_sched.h>.
* tests/test_nlattr.h (TEST_NESTED_NLATTR_ARRAY_EX): Rename from
TEST_NESTED_NLATTR_ARRAY, add depth_ argument, perform padding and
output accordingly.
(TEST_NESTED_NLATTR_ARRAY): New macro, a thin wrapper around
TEST_NESTED_NLATTR_ARRAY_EX.
* tests/nlattr_tca_stab.c [!HAVE_DECL_TCA_STAB_DATA] (TCA_STAB_DATA):
New enumeration declaration.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
tests: pass index to print_elem_ callback in TEST_NLATTR_NESTED_ARRAY
* tests/test_nlattr.h (TEST_NLATTR_NESTED_ARRAY): Pass array index
to the print_elem_ callback.
* tests/nlattr_tca_stab.c (print_uint16): Add index argument.
tests: move common ifinfomsg boilerplate into a separate header
* configure.ac (AC_CHECK_DECLS): Check for IFLA_PORT_SELF, IFLA_PROTINFO, and
IFLA_XDP in <linux/rtnetlink.h>.
* tests/nlattr_ifla.h: New file.
* tests/Makefile.am (EXTRA_DIST): Add it.
* tests/nlattr_ifla_brport.c [!HAVE_DECL_IFLA_PROTINFO] (IFLA_PROTINFO):
New declaration.
(hdrlen, init_ifinfomsg, print_ifinfomsg): Remove.
(IFLA_ATTR): Define to IFLA_PROTINFO.
Include nlattr_ifla.h.
* tests/nlattr_ifla_port.c [!HAVE_DECL_IFLA_PORT_SELF] (IFLA_PORT_SELF):
New declaration.
(hdrlen, init_ifinfomsg, print_ifinfomsg): Remove.
(IFLA_ATTR): Define to IFLA_PORT_SELF.
Include nlattr_ifla.h.
* tests/nlattr_ifla_xdp.c
* tests/nlattr_ifla_xdp.c [!HAVE_DECL_IFLA_XDP] (IFLA_XDP): New
declaration.
(hdrlen, init_ifinfomsg, print_ifinfomsg): Remove.
(IFLA_ATTR): Define to IFLA_XDP.
Include nlattr_ifla.h.
rtnl_link: implement IFLA_INFO_DATA for tun devices
* xlat/rtnl_ifla_info_data_tun_attrs.in: New file.
* xlat/tun_device_types.in: Likewise.
* rtnl_link.c: Include xlat/rtnl_ifla_info_data_tun_attrs.h and
xlat/tun_device_types.h.
(decode_nla_tun_type, decode_nla_linkinfo_data_tun): New functions.
(ifla_info_data_tun_nla_decoders): New decoder dispatcher table.
(decode_nla_linkinfo_data): Use decode_nla_linkinfo_data_tun if kind
is
"tun".
* xlat/rtnl_ifla_info_data_bridge_attrs.in: New file.
* rtnl_link.c: Include xlat/rtnl_ifla_info_data_bridge_attrs.h.
(ifla_info_data_bridge_nla_decoders): New decoder dispatcher table.
(decode_nla_linkinfo_data_bridge, decode_nla_linkinfo_data): New
functions.
(ifla_linkinfo_nla_decoders) <IFLA_INFO_DATA>: Use
decode_nla_linkinfo_data as a decoder.
* rtnl_link.c (decode_nla_linkinfo_xstats_can,
decode_nla_linkinfo_xstats): New function.
(ifla_linkinfo_nla_decoders) <IFLA_INFO_XSTATS>: Use
decode_nla_linkinfo_xstats as a decoder.
Dispatch for IFLA_INFO_* attributes should be performed based on the
string provided in a IFLA_INFO_KIND attribute.
* nlattr.h (struct ifla_linkinfo_ctx): New type definition.
* rtnl_link.c (decode_nla_linkinfo_kind): New function.
(ifla_linkinfo_nla_decoders) <IFLA_INFO_KIND>: Use
decode_nla_linkinfo_kind as decoder.
(decode_ifla_linkinfo): Add struct ifla_linkinfo_ctx context, pass it to
the decode_nlattr call as opaque data.
nlattr: add size check to decode_nla_xval and decode_nla_flags
If the field size is known, do not print as valid numbers those
attributes that are too short, and ignore extra data.
This change puts xval/flags printing in line with the reset of attribute
decoders.
* nlattr.h (struct decode_nla_xlat_opts): Add size field.
* nlattr.c (decode_nla_xval, decode_nla_flags): Check that len is at
least opts->size, limit len to opts->size.
(decode_nla_ip_proto): Specify size of 1.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
nlattr: add value processing support for xlat/flags nlattr decoders
Needed for upcoming decoder of ethernet proto which is stored in the
host order and has to be converted to the network order before printing
as an xval constant. This change also adds ability to provide
prefix/suffix in order to enclose the printed value in something that
describes the performed conversion.
nlattr: add ability to pass nla_type to decoder in decode_nlattr
As of now, it's impossible to introduce a dispatching nlattr decoder
that performs actions based on the type of the message, so let's use
a combination of zero decoder list size and non-zero decoder pointer
for this.
This is going to be used later in IFLA_AF_SPEC decoding.
* nlattr.c (decode_nlattr_with_data): Handle zero size and non-NULL
decoders in a special way.
(decode_nlattr): Add an error message about ignoring of opaque_data
argument when zero size and non-NULL decoders are provided.
* nlattr.h (decode_nlattr): Add a comment about the new special case.
xlat.c: handle NULL xlat in lookup routines as incremental search
This is going to be used later in IFLA_AF_SPEC decoding.
* xlat.c (xlookup): Add static variable pos, store xlat there when it is
non-NULL, use pos for lookup.
(xlat_search, xlat_idx): Add static variables pos and memb_left, store
xlat and nmemb there when xlat is non-NULL, use them for lookup.
(printxvals_ex): Store the last non-NULL xlat in static variable "last".
If the first xlat argument is NULL, use "last" instead.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
* rtnl_link.c (DECL_NETLINK_ROUTE_DECODER(decode_ifinfomsg)): Use
PRINT_FIELD_XVAL_SORTED_SIZED instead of PRINT_FIELD_XVAL for
arp_hardware_types.
* sock.c (print_ifreq): Likewise.
Dmitry V. Levin [Mon, 4 Jun 2018 01:11:05 +0000 (01:11 +0000)]
bpf: enhance BPF_OBJ_GET_INFO_BY_FD decoder further
* bpf.c (print_ebpf_prog): Remove "decode" argument, all users updated.
(print_bpf_prog_info): Use the minimum of xlated_prog_len values on
entering and exiting syscall as the size of xlated_prog_insns array
to be decoded. Likewise, use the minimum of nr_map_ids values on entering
and exiting syscall as the size of map_ids array to be decoded.
* bpf.c (print_bpf_map_info): Print only those fields that are
present in the structure, as it has been growing over time.
(print_bpf_prog_info): Likewise. Print map_ids field as an array
of uint32_t instead of uint64_t; print "name" field.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
bpf: move handling of the saved state to BPF_OBJ_GET_INFO_BY_FD decoder
As it is needed for proper info_len printing on exiting.
* bpf.c (print_bpf_obj_info_fn): Change return type to void, add "saved"
argument.
(struct obj_get_info_saved): New type definition.
(print_bpf_map_info, print_bpf_prog_info): Change return type to void,
add "saved" argument, do not handle private tcb data allocation and
obtainment.
(print_bpf_obj_info_addr): Change return type to void, add tcb argument,
print the address only on exiting.
(print_bpf_obj_info): Change return type to void, add "saved" argument.
(BEGIN_BPF_CMD_DECODER(BPF_OBJ_GET_INFO_BY_FD)): Handle private data
allocation/saving/restoring, use it for storing/printing info_len field.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
bpf: print xlated_prog_insns only when xlated_prog_len had not been 0
If xlated_prog_len is zero on entering syscall and non-zero on exiting,
the program itself is not written into xlated_prog_insns.
* bpf.c (print_ebpf_prog): Add decode argument, print the address only
if decode is false.
(BEGIN_BPF_CMD_DECODER(BPF_PROG_LOAD)): Specify decode == true argument
to print_ebpf_prog.
(print_bpf_prog_info): Specify saved xlated_prog_len as decode argument
to print_ebpf_prog.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
* bpf.c (print_ebpf_prog): Add static qualifier. Change the type
of "addr" argument from kernel_ulong_t to uint64_t, print it using
print_big_u64_addr.
(BEGIN_BPF_CMD_DECODER(BPF_PROG_LOAD), print_bpf_prog_info): Do not call
print_big_u64_addr before print_ebpf_prog.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
tests: cast printf arguments to short when %h format qualifier is used
Reported by clang.
* tests/mknod.c (main): Cast printf argument for %#03ho format to short.
* tests/mknodat.c (main): Likewise.
* tests/net-sockaddr.c (main): Cast printf argument for %hu format
to short.
* tests/semop.c (main): Likewise.
configure.ac: check for linux/rtnetlink.h instead of linux/if_link.h for declarations
Historically, type definitions and declarations related to netlink route
interface attributes were in linux/rtnetlink.h, later they were moved
elsewhere (first linux/if.h, then linux/if_link.h) with the inclusion
of the corresponding header file in linux/rtnetlink.h.
* configure.ac: Use <linux/rtnetlink.h> instead of <linux/if_link.h>
in checks for interface netlink attributes-related declarations
and definitions.
tests: check decoding of new FRA_* netlink attributes
* configure.ac (AC_CHECK_TYPES): Check for struct fib_rule_port_range
in <linux/fib_rules.h>.
* tests/nlattr_fib_rule_hdr.c: Include <linux/in.h>.
(FRA_PROTOCOL, FRA_IP_PROTO, FRA_SPORT_RANGE, FRA_DPORT_RANGE): New
macro constants.
[!HAVE_STRUCT_FIB_RULE_PORT_RANGE] (struct fib_rule_port_range): New
type.
(main): Check decoding of new FRA_* netlink attributes.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
tests: use syscall() for ioctl() calls with oversized arguments
* tests/ioctl_inotify.c (sys_ioctl): New function.
(main): Use sys_ioctl for ioctl calls with oversized arguments.
* tests/ioctl_loop.c: Likewise.
* tests/ioctl_perf.c: Likewise.
Print interface indices according to the preferred xlat style settings.
* print_ifindex.c (INI_PFX, INI_SFX): New helper macros.
[HAVE_IF_INDEXTONAME] (get_ifname): New function.
[HAVE_IF_INDEXTONAME] (print_ifindex): Implement as a wrapper around
get_ifname and print_xlat_ex.
nlattr: print index names in netlink meminfo array
* xlat/netlink_sk_meminfo_indices.in: New file.
* nlattr.c: Include xlat/netlink_sk_meminfo_indices.h.
(decode_nla_meminfo): Use print_array_ex, pass
netlink_sk_meminfo_indices as index xlat table.
* tests/nlattr_inet_diag_msg.c: Update expected output.
print_array: add support for printing array indices
* defs.h (XLAT_STYLE_SPEC_BITS, XLAT_STYLE_MASK): New macro constants.
(tfetch_mem_fn, print_fn): New typedefs.
(enum print_array_flag_bits, enum print_array_flags): New enumerations.
(print_array_ex): Rename from print_array, add flags, index_xlat,
index_xlat_size, and index_dflt arguments.
(print_array): New static inline function, a thin wrapper around
print_array_ex.
util.c: Include "xlat.h".
(print_array): Rename to print_array_ex, add flags, index_xlat,
index_xlat_size, and index_dflt arguments. Print array indices
according to the style settings specified by flags if PAF_PRINT_INDICES
is set.
Dmitry V. Levin [Tue, 29 May 2018 01:15:19 +0000 (01:15 +0000)]
print_array: enhance printing of unfetchable object addresses
When umoven_func invocation fails to fetch data, it prints the faulty
address. If this happens to a subsequent umoven_func invocation,
the printed address may be undistinguishable from a valid data printed
by print_func, e.g. when the data is printed in a numeric form like
[0x1, 0x2, 0x3, 0xdefaced].
Fix this source of confusion by moving the printing of the faulty
address from umoven_func to print_array itself. This change renames
umoven_func to tfetch_mem_func and changes its semantics, so that
- tfetch_mem_func never prints anything;
- tfetch_mem_func returns true if the fetch succeeded,
and false otherwise.
Dmitry V. Levin [Mon, 28 May 2018 11:32:03 +0000 (11:32 +0000)]
Introduce tfetch_* family of functions and macros
These new functions are going to be used instead of umove_or_printaddr*
as umoven_func argument of print_array.
* defs.h (tfetch_mem64, tfetch_mem64_ignore_syserror): New
function prototypes.
(tfetch_mem, tfetch_mem_ignore_syserror): New static inline
wrappers.
(tfetch_obj): New macro wrapper around tfetch_mem.
* util.c (tfetch_mem64, tfetch_mem64_ignore_syserror): New
functions.
(umoven_or_printaddr64, umoven_or_printaddr64_ignore_syserror): Use
them.
bpf: decode bpf_attr.info field used by BPF_OBJ_GET_INFO_BY_FD command
* bpf_attr.h [!BPF_TAG_SIZE] (BPF_TAG_SIZE): Define.
[BPF_TAG_SIZE]: Check that BPF_TAG_SIZE is 8.
(struct bpf_map_info_struct, struct bpf_prog_info_struct): New
structures.
(bpf_map_info_struct_size, expected_bpf_map_info_struct_size,
bpf_prog_info_struct_size, expected_bpf_prog_info_struct_size): New
macro constants.
* bpf.c (print_bpf_obj_info_fn): New type.
(print_bpf_map_info, print_bpf_prog_info, fetch_bpf_obj_info,
print_bpf_obj_info_addr, print_bpf_obj_info): New functions.
(BEGIN_BPF_CMD_DECODER(BPF_OBJ_GET_INFO_BY_FD)): Print bpf_fd and info_len
fields only on entering, call print_bpf_obj_info for printing info field.
* tests/bpf.c (BPF_OBJ_GET_INFO_BY_FD_checks): Print info field
as a pointer.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
bpf: add support for checking structures outside union bpf_attr
struct bpf_prog_info and bpf_map_info need essentially the same handling
as union bpf_attr.
* gen_bpf_attr_check.sh: Derive type_name from $struct if it doesn't
start with "BPF_", derive TYPE_NAME from type_name, use them in code
generation.
* m4/gen_bpf_attr_m4.sh: Rewrite parsing/generation code into awk,
add support for structures outside union bpf_attr.
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
Dmitry V. Levin [Sat, 26 May 2018 10:32:54 +0000 (10:32 +0000)]
bpf: remove bpf_priv_data
As various bpf commands need different data to save between entering
and exiting of the syscall, do not emulate union bpf_attr approach.
* bpf.c (struct bpf_priv_data): Remove.
(DECL_BPF_CMD_DECODER): Remove "struct bpf_priv_data *" argument.
(BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)): Use set_tcb_priv_ulong
and get_tcb_priv_ulong to keep bpf_attr.query.prog_cnt field.
(SYS_FUNC(bpf)): Remove priv variable, do not initialize it,
and do not pass it to bpf_cmd_decoders.
tests: add union bpf_attr.query.prog_ids field decoding checks
* tests/bpf-success-v.c: New file.
* tests/bpf-success.c: Likewise.
* tests/bpf-success-v.test: New test.
* tests/bpf-success.test: Likewise.
* tests/.gitignore: Add bpf-success and bpf-success-v.
* tests/Makefile.am (check_PROGRAMS): Likewise.
(DECODER_TESTS): Add bpf-success.test and bpf-success-v.test.
* tests/bpf.c [INJECT_RETVAL] (sys_bpf): Check that retuned value
is equivalent to the injected one; append "(INJECTED)" string to errstr.
(prog_load_ids, prog_load_ids_ptr): New variables.
(init_BPF_PROG_QUERY_attr4, print_BPF_PROG_QUERY_attr4,
init_BPF_PROG_QUERY_attr5, print_BPF_PROG_QUERY_attr5): New functions.
(BPF_PROG_QUERY_checks): Drop "const" qualifier, add new checks.
* bpf.c (BEGIN_BPF_CMD_DECODER(BPF_PROG_QUERY)): Use
print_uint32_array_member instead of print_uint64_array_member for
printing prog_ids elements (and change the type of prog_id_buf from
uint64_t to uint32_t), as they are 32-bit; use common trick with
print_big_u64_addr for handling possible ambiguity with prog_ids
address.
* tests/bpf.c (BIG_ADDR_MAYBE): New macro.
(BPF_PROG_QUERY_checks): Update expected output.
* xlat/ebpf_regs.in: New file.
* bpf.c (struct ebpf_insn, struct ebpf_insns_data): New type definitions.
(print_ebpf_insn, print_ebpf_prog): New functions.
(DEF_BPF_CMD_DECODER(BPF_PROG_LOAD)): Use them.
* xlat/inet_protocols.in (IPPROTO_GGP, IPPROTO_HELLO, IPPROTO_ND):
Remove, not defined in Linux.
(IPPROTO_BEETPH): New constant, introduced by Linux commit
v2.6.19-rc1~33^2.
(IPPROTO_L2TP): New constant, introduced by Linux commit
v2.6.35-rc1~473^2~594.
(IPPROTO_MH): New constant, introduced by Linux commit
v2.6.19-rc1~1272^2~157.
Add default values to constants, sort the file.
There's little reason not to decode error code for syscalls printed in
raw; moreover, it creates inconsistencies for unknown syscall printing.
Another issue was with error numbers unknown to strace: previously, they
were printed as "... = -1 1234 (Unknown error 1234)" which looked kinda
weird.
* syscall.c (print_err_ret): New function.
(syscall_exiting_trace): Remove u_error variable, use tcp->u_error
instead. Remove u_error_str variable.
(syscall_exiting_trace) <if (raw(tcp))>: Call print_err_ret if u_error
is non-zero.
(syscall_exiting_trace) <if (!(sys_res & RVAL_NONE) && tcp->u_error)>:
Use print_err_ret for default error printing.
* tests/nsyscalls.c [!LINUX_MIPSO32] (test_syscall): Update expected
output.
* tests/qual_fault.c (invoke) <if (is_raw)>: Likewise.
* strace.1.in (.SH DESCIPTION): Update unknown syscall example.