This change introduces new filtering architecture primitives: filter, filter_action and bool_expression. Filtering is now done after decoding of syscall and tcp->qual_flg stores filtering results.
* basic_actions.c: New file. * filter_action.c: Likewise. * filter_expression.c: Likewise. * filter.c: Likewise. * basic_filters.c (qualify_tokens): Remove 'handle_inversion' label, do not clear the set. (qualify_syscall_tokens): Likewise. Remove "name" argument(assume "system call"). (parse_syscall_filter, parse_fd_filter, parse_path_filter, run_syscall_filter, run_fd_filter, run_path_filter, free_syscall_filter, free_fd_filter, free_path_filter): New functions. * defs.h (struct inject_opts): Add init flag. (qual_flags): Remove old declaration. (filter_syscall, filtering_parsing_finish): Add new declarations. * filter.h: Add new declarations. (qualify_syscall_tokens): Change declaration. * filter_qualify.c (read_set, write_set, abbrev_set, inject_set, raw_set, trace_set, verbose_set): Remove set variables. (parse_inject_expression): Remove function. (parse_inject_common_args): New function. (qualify_signals): Clear set before use. (qualify_read, qualify_write, qualify_trace, qualify_abbrev, qualify_verbose, qualify_raw): Use new filtering API. (qualify_inject_common): Likewise. Use parse_inject_common_args for parsing. (qualify_fault, qualify_inject): Remove "argument" from description argument of qualify_inject_common. (qual_flags): Remove function. * number_set.h (read_set, write_set): Remove set declarations. * pathtrace.c (storepath): Duplicate paths. * strace.c (init): Call filtering_parse_finish after command line parsing. (trace_syscall): Add filtering after syscall decoding. (droptcb): Don't free inject_vec for empty personalities. * syscall.c (decode_socket_subcall): Remove qual_flags from decoder. (decode_ipc_subcall): Likewise. (decode_mips_subcall): Likewise. (get_scno): Likewise. (inject_vec, tamper_with_syscall_entering): Remove inject_vec support code. (dumpio): Check dump_read, dump_write macros instead of global sets. --- Makefile.am | 4 + basic_actions.c | 130 ++++++++++++++++++++++++ basic_filters.c | 111 ++++++++++++++++++--- defs.h | 4 +- filter.c | 144 +++++++++++++++++++++++++++ filter.h | 34 ++++++- filter_action.c | 240 ++++++++++++++++++++++++++++++++++++++++++++ filter_expression.c | 281 ++++++++++++++++++++++++++++++++++++++++++++++++++++ filter_qualify.c | 196 +++++++++++++++--------------------- number_set.h | 2 - pathtrace.c | 2 +- strace.c | 6 +- syscall.c | 20 +--- 13 files changed, 1018 insertions(+), 156 deletions(-) create mode 100644 basic_actions.c create mode 100644 filter.c create mode 100644 filter_action.c create mode 100644 filter_expression.c diff --git a/Makefile.am b/Makefile.am index b3afc7c5..b928eb28 100644 --- a/Makefile.am +++ b/Makefile.am @@ -86,6 +86,7 @@ strace_SOURCES = \ affinity.c \ aio.c \ alpha.c \ + basic_actions.c \ basic_filters.c \ bind.c \ bjm.c \ @@ -133,7 +134,10 @@ strace_SOURCES = \ fetch_struct_statfs.c \ file_handle.c \ file_ioctl.c \ + filter_action.c \ + filter_expression.c \ filter_qualify.c \ + filter.c \ filter.h \ flock.c \ flock.h \ diff --git a/basic_actions.c b/basic_actions.c new file mode 100644 index 00000000..740a9d5e --- /dev/null +++ b/basic_actions.c @@ -0,0 +1,130 @@ +/* + * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikola...@gmail.com> + * 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 "filter.h" + +bool +is_traced(struct tcb *tcp) +{ + return traced(tcp); +} + +bool +not_injected(struct tcb *tcp) +{ + return !inject(tcp); +} + +void * +parse_null(const char *str) +{ + return NULL; +} + +void +apply_trace(struct tcb *tcp, void *_priv_data) +{ + tcp->qual_flg |= QUAL_TRACE; +} + +void +apply_inject(struct tcb *tcp, void *_priv_data) +{ + struct inject_opts *opts = _priv_data; + + tcp->qual_flg |= QUAL_INJECT; + if (!tcp->inject_vec[current_personality]) + tcp->inject_vec[current_personality] = + xcalloc(nsyscalls, sizeof(struct inject_opts)); + if (scno_in_range(tcp->scno) + && !tcp->inject_vec[current_personality][tcp->scno].init) + tcp->inject_vec[current_personality][tcp->scno] = *opts; +} + +static void * +parse_inject_common(const char *str, bool fault_tokens_only, + const char *description) +{ + struct inject_opts *opts = xmalloc(sizeof(struct inject_opts)); + char *buf = xstrdup(str); + + parse_inject_common_args(buf, opts, fault_tokens_only, false); + if (!opts->init) + error_msg_and_die("invalid %s argument '%s'", + description, str ? str : ""); + free(buf); + return opts; +} + +void * +parse_inject(const char *str) +{ + return parse_inject_common(str, false, "inject"); +} + +void +apply_fault(struct tcb *tcp, void *_priv_data) +{ + apply_inject(tcp, _priv_data); +} + +void * +parse_fault(const char *str) +{ + return parse_inject_common(str, true, "fault"); +} + +void +apply_read(struct tcb *tcp, void *_priv_data) +{ + tcp->qual_flg |= QUAL_READ; +} + +void +apply_write(struct tcb *tcp, void *_priv_data) +{ + tcp->qual_flg |= QUAL_WRITE; +} + +void +apply_raw(struct tcb *tcp, void *_priv_data) +{ + tcp->qual_flg |= QUAL_RAW; +} + +void +apply_abbrev(struct tcb *tcp, void *_priv_data) +{ + tcp->qual_flg |= QUAL_ABBREV; +} + +void +apply_verbose(struct tcb *tcp, void *_priv_data) +{ + tcp->qual_flg |= QUAL_VERBOSE; +} diff --git a/basic_filters.c b/basic_filters.c index 7b7f0a54..578df40c 100644 --- a/basic_filters.c +++ b/basic_filters.c @@ -202,18 +202,14 @@ qualify_syscall(const char *token, struct number_set *set) * according to STR specification. */ void -qualify_syscall_tokens(const char *const str, struct number_set *const set, - const char *const name) +qualify_syscall_tokens(const char *const str, struct number_set *const set) { - /* Clear all sets. */ - clear_number_set_array(set, SUPPORTED_PERSONALITIES); - /* * Each leading ! character means inversion * of the remaining specification. */ const char *s = str; -handle_inversion: + while (*s == '!') { invert_number_set_array(set, SUPPORTED_PERSONALITIES); ++s; @@ -227,8 +223,8 @@ handle_inversion: */ return; } else if (strcmp(s, "all") == 0) { - s = "!none"; - goto handle_inversion; + invert_number_set_array(set, SUPPORTED_PERSONALITIES); + return; } /* @@ -247,17 +243,43 @@ handle_inversion: token = strtok_r(NULL, ",", &saveptr)) { done = qualify_syscall(token, set); if (!done) { - error_msg_and_die("invalid %s '%s'", name, token); + error_msg_and_die("invalid system call '%s'", token); } } free(copy); if (!done) { - error_msg_and_die("invalid %s '%s'", name, str); + error_msg_and_die("invalid system call '%s'", str); } } +void * +parse_syscall_filter(const char *str) +{ + struct number_set *set; + + set = alloc_number_set_array(SUPPORTED_PERSONALITIES); + qualify_syscall_tokens(str, set); + return set; +} + +bool +run_syscall_filter(struct tcb *tcp, void *_priv_data) +{ + struct number_set *set = _priv_data; + + return is_number_in_set_array(tcp->scno, set, current_personality); +} + +void +free_syscall_filter(void *_priv_data) +{ + struct number_set *set = _priv_data; + + free_number_set_array(set, SUPPORTED_PERSONALITIES); +} + /* * Add numbers to SET according to STR specification. */ @@ -265,15 +287,12 @@ void qualify_tokens(const char *const str, struct number_set *const set, string_to_uint_func func, const char *const name) { - /* Clear the set. */ - clear_number_set_array(set, 1); - /* * Each leading ! character means inversion * of the remaining specification. */ const char *s = str; -handle_inversion: + while (*s == '!') { invert_number_set_array(set, 1); ++s; @@ -287,8 +306,8 @@ handle_inversion: */ return; } else if (strcmp(s, "all") == 0) { - s = "!none"; - goto handle_inversion; + invert_number_set_array(set, 1); + return; } /* @@ -319,3 +338,63 @@ handle_inversion: error_msg_and_die("invalid %s '%s'", name, str); } } + +void * +parse_fd_filter(const char *str) +{ + struct number_set *set; + + set = alloc_number_set_array(1); + qualify_tokens(str, set, string_to_uint, "descriptor"); + return set; +} + +bool +run_fd_filter(struct tcb *tcp, void *_priv_data) +{ + int fd = tcp->u_arg[0]; + struct number_set *set = _priv_data; + + if (fd < 0) + return false; + return is_number_in_set(fd, set); +} + +void +free_fd_filter(void *_priv_data) +{ + struct number_set *set = _priv_data; + + free_number_set_array(set, 1); + return; +} + +void * +parse_path_filter(const char *path, const char *const name) +{ + struct path_set *set = xcalloc(1, sizeof(struct path_set)); + + pathtrace_select_set(path, set); + return set; +} + +bool +run_path_filter(struct tcb *tcp, void *_priv_data) +{ + struct path_set *set = _priv_data; + + return pathtrace_match_set(tcp, set); +} + +void +free_path_filter(void *_priv_data) +{ + struct path_set *set = _priv_data; + unsigned int i; + + for (i = 0; i < set->num_selected; ++i) + free((char *) set->paths_selected[i]); + free(set->paths_selected); + free(set); + return; +} diff --git a/defs.h b/defs.h index 87f831f1..4bd8d9e0 100644 --- a/defs.h +++ b/defs.h @@ -185,6 +185,7 @@ struct inject_opts { uint16_t step; uint16_t signo; int rval; + bool init; }; #define MAX_ERRNO_VALUE 4095 @@ -650,7 +651,8 @@ print_struct_statfs64(struct tcb *, kernel_ulong_t addr, kernel_ulong_t size); extern void print_ifindex(unsigned int); extern void qualify(const char *); -extern unsigned int qual_flags(const unsigned int); +extern void filtering_parsing_finish(void); +extern void filter_syscall(struct tcb *); #define DECL_IOCTL(name) \ extern int \ diff --git a/filter.c b/filter.c new file mode 100644 index 00000000..9c9b7e0d --- /dev/null +++ b/filter.c @@ -0,0 +1,144 @@ +/* + * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikola...@gmail.com> + * 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 "filter.h" + +#define DECL_FILTER(name) \ +extern void * \ +parse_ ## name ## _filter(const char *); \ +extern bool \ +run_ ## name ## _filter(struct tcb *, void *); \ +extern void \ +free_ ## name ## _filter(void *) \ +/* End of DECL_FILTER definition. */ + +DECL_FILTER(syscall); +DECL_FILTER(fd); +DECL_FILTER(path); +#undef DECL_FILTER + +#define FILTER_TYPE(name) \ +{#name, parse_ ## name ## _filter, run_ ## name ## _filter, \ + free_ ## name ## _filter} +/* End of FILTER_TYPE definition. */ + +static const struct filter_type { + const char *name; + void *(*parse_filter)(const char *); + bool (*run_filter)(struct tcb *, void *); + void (*free_priv_data)(void *); +} filter_types[] = { + FILTER_TYPE(syscall), + FILTER_TYPE(fd), + FILTER_TYPE(path), +}; +#undef FILTER_TYPE + +struct filter { + const struct filter_type *type; + void *_priv_data; +}; + +static const struct filter_type * +lookup_filter_type(const char *str) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(filter_types); i++) { + if (!strcmp(filter_types[i].name, str)) + return &filter_types[i]; + } + return NULL; +} + +struct filter * +add_filter_to_array(struct filter **filters, unsigned int *nfilters, + const char *name) +{ + const struct filter_type *type = lookup_filter_type(name); + struct filter *filter; + + if (!type) + error_msg_and_die("invalid filter '%s'", name); + *filters = xreallocarray(*filters, ++(*nfilters), + sizeof(struct filter)); + filter = &((*filters)[*nfilters - 1]); + filter->type = type; + return filter; +} + +void +parse_filter(struct filter *filter, const char *str) +{ + filter->_priv_data = filter->type->parse_filter(str); +} + +static bool +run_filter(struct tcb *tcp, struct filter *filter) +{ + return filter->type->run_filter(tcp, filter->_priv_data); +} + +void +run_filters(struct tcb *tcp, struct filter *filters, unsigned int nfilters, + bool *variables_buf) +{ + unsigned int i; + + for (i = 0; i < nfilters; ++i) + variables_buf[i] = run_filter(tcp, &filters[i]); +} + +void +free_filter(struct filter *filter) +{ + if (!filter) + return; + filter->type->free_priv_data(filter->_priv_data); +} + +void +set_filter_priv_data(struct filter *filter, void *_priv_data) +{ + if (filter) + filter->_priv_data = _priv_data; +} + +void +set_filters_qualify_mode(struct filter **filters, unsigned int *nfilters, + unsigned int filters_left) +{ + unsigned int i; + + for (i = 0; i < *nfilters - filters_left; ++i) + free_filter(*filters + i); + for (i = 0; i < filters_left; ++i) + (*filters)[i] = (*filters)[*nfilters - filters_left + i]; + *filters = xreallocarray(*filters, filters_left, sizeof(struct filter)); + *nfilters = filters_left; +} diff --git a/filter.h b/filter.h index fab18127..e340aac3 100644 --- a/filter.h +++ b/filter.h @@ -30,11 +30,41 @@ #define STRACE_FILTER_H struct number_set; + +struct filter; + +struct filter_action; + +struct bool_expression; + typedef int (*string_to_uint_func)(const char *); void qualify_tokens(const char *str, struct number_set *set, string_to_uint_func func, const char *name); -void qualify_syscall_tokens(const char *str, struct number_set *set, - const char *name); +void qualify_syscall_tokens(const char *str, struct number_set *set); +void parse_inject_common_args(char *, struct inject_opts *, + const bool fault_tokens_only, bool qualify_mode); + +/* filter api */ +struct filter* add_filter_to_array(struct filter **, unsigned int *nfilters, + const char *name); +void parse_filter(struct filter *, const char *str); +void run_filters(struct tcb *, struct filter *, unsigned int, bool *); +void free_filter(struct filter *); +void set_filter_priv_data(struct filter *, void *); +void set_filters_qualify_mode(struct filter **, unsigned int *nfilters, + unsigned int filters_left); + +/* filter action api */ +struct filter *create_filter(struct filter_action *, const char *name); +struct filter_action *find_or_add_action(const char *); +void set_filter_action_priv_data(struct filter_action *, void *); +void set_qualify_mode(struct filter_action *, unsigned int); + +/* filter expression api */ +struct bool_expression *create_expression(); +bool run_expression(struct bool_expression *, bool *, unsigned int); +void set_expression_qualify_mode(struct bool_expression *, unsigned int); +void expression_add_filter_and(struct bool_expression *, unsigned int); #endif /* !STRACE_FILTER_H */ diff --git a/filter_action.c b/filter_action.c new file mode 100644 index 00000000..0f75f2e5 --- /dev/null +++ b/filter_action.c @@ -0,0 +1,240 @@ +/* + * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikola...@gmail.com> + * 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 "filter.h" + +#define DECL_FILTER_ACTION(name) \ +extern void \ +apply_ ## name(struct tcb *, void *) \ +/* End of DECL_FILTER_ACTION definition. */ + +DECL_FILTER_ACTION(trace); +DECL_FILTER_ACTION(inject); +DECL_FILTER_ACTION(fault); +DECL_FILTER_ACTION(read); +DECL_FILTER_ACTION(write); +DECL_FILTER_ACTION(raw); +DECL_FILTER_ACTION(abbrev); +DECL_FILTER_ACTION(verbose); +#undef DECL_FILTER_ACTION + +extern bool is_traced(struct tcb *); +extern bool not_injected(struct tcb *); + +#define DECL_FILTER_ACTION_PARSER(name) \ +extern void * \ +parse_ ## name(const char *); \ +/* End of DECL_FILTER_ACTION_PARSER definition. */ + +DECL_FILTER_ACTION_PARSER(null); +DECL_FILTER_ACTION_PARSER(inject); +DECL_FILTER_ACTION_PARSER(fault); +#undef DECL_FILTER_ACTION_PARSER + +#define FILTER_ACTION_TYPE(NAME, PRIORITY, FLAG, PARSER, PREFILTER) \ +{#NAME, PRIORITY, FLAG, parse_ ## PARSER, PREFILTER, apply_ ## NAME} +/* End of FILTER_ACTION_TYPE definition. */ + +static const struct filter_action_type { + const char *name; + /* The highest priority is 0. */ + unsigned int priority; + unsigned int qual_flg; + void * (*parse_args)(const char *); + bool (*prefilter)(struct tcb *); + void (*apply)(struct tcb *, void *); +} action_types[] = { + FILTER_ACTION_TYPE(trace, 0, QUAL_TRACE, null, NULL), + FILTER_ACTION_TYPE(inject, 1, QUAL_INJECT, inject, not_injected), + FILTER_ACTION_TYPE(fault, 1, QUAL_INJECT, fault, not_injected), + FILTER_ACTION_TYPE(read, 2, QUAL_READ, null, is_traced), + FILTER_ACTION_TYPE(write, 2, QUAL_WRITE, null, is_traced), + FILTER_ACTION_TYPE(raw, 2, QUAL_RAW, null, is_traced), + FILTER_ACTION_TYPE(abbrev, 2, QUAL_ABBREV, null, is_traced), + FILTER_ACTION_TYPE(verbose, 2, QUAL_VERBOSE, null, is_traced), +}; +#undef FILTER_ACTION_TYPE + +struct filter_action { + /* Used to correct order of actions with the same priority. */ + unsigned int id; + const struct filter_action_type *type; + struct bool_expression *expr; + unsigned int nfilters; + struct filter *filters; + void *_priv_data; +}; + +static struct filter_action *filter_actions; +static unsigned int nfilter_actions; + +static bool *variables_buf; + +/* + * Compares action priorities. If actions have the same priority, + * uses LIFO order. + */ +static int +compare_action_priority(const void *a, const void *b) +{ + const struct filter_action *action_a = a; + const struct filter_action *action_b = b; + unsigned int priority_a = action_a->type->priority; + unsigned int priority_b = action_b->type->priority; + + if (priority_a != priority_b) { + return (priority_a < priority_b) ? -1 : 1; + } else { + return (action_a->id > action_b->id) ? -1 : 1; + } +} + +static void +inject_path_tracing(void) +{ + struct filter_action *action = find_or_add_action("trace"); + struct filter *path_filter; + + if (!action->nfilters) + qualify("trace=all"); + path_filter = add_filter_to_array(&action->filters, &action->nfilters, + "path"); + set_filter_priv_data(path_filter, &global_path_set); + expression_add_filter_and(action->expr, action->nfilters - 1); +} + +void +filtering_parsing_finish(void) +{ + unsigned int maxfilters = 0; + unsigned int i; + + /* Inject path filter into trace action. */ + if (tracing_paths) + inject_path_tracing(); + + /* Sort actions by priority */ + if (nfilter_actions == 0) + return; + qsort(filter_actions, nfilter_actions, sizeof(struct filter_action), + &compare_action_priority); + + /* Allocate variables_buf sufficient for any action */ + for (i = 0; i < nfilter_actions; ++i) { + if (filter_actions[i].nfilters > maxfilters) + maxfilters = filter_actions[i].nfilters; + } + variables_buf = xcalloc(maxfilters, sizeof(bool)); +} + +static const struct filter_action_type * +lookup_filter_action_type(const char *str) +{ + unsigned int i; + + for (i = 0; i < ARRAY_SIZE(action_types); ++i) { + if (!strcmp(action_types[i].name, str)) + return &action_types[i]; + } + return NULL; +} + +static struct filter_action * +add_action(const struct filter_action_type *type) +{ + struct filter_action *action; + + filter_actions = xreallocarray(filter_actions, ++nfilter_actions, + sizeof(struct filter_action)); + action = &filter_actions[nfilter_actions - 1]; + memset(action, 0, sizeof(*action)); + action->id = nfilter_actions - 1; + action->type = type; + action->expr = create_expression(); + return action; +} + +struct filter_action * +find_or_add_action(const char *name) +{ + const struct filter_action_type *type = lookup_filter_action_type(name); + unsigned int i; + + if (!type) + error_msg_and_die("invalid filter action '%s'", name); + /* If action takes arguments, add new action */ + if (type->parse_args != &parse_null) + return add_action(type); + + for (i = 0; i < nfilter_actions; ++i) { + if (filter_actions[i].type == type) + return &filter_actions[i]; + } + return add_action(type); +} + +static void +run_filter_action(struct tcb *tcp, struct filter_action *action) +{ + if (action->type->prefilter && !action->type->prefilter(tcp)) + return; + run_filters(tcp, action->filters, action->nfilters, variables_buf); + if (run_expression(action->expr, variables_buf, action->nfilters)) + action->type->apply(tcp, action->_priv_data); +} + +struct filter * +create_filter(struct filter_action *action, const char *name) +{ + return add_filter_to_array(&action->filters, &action->nfilters, name); +} + +void +set_qualify_mode(struct filter_action *action, unsigned int filters_left) +{ + set_filters_qualify_mode(&action->filters, &action->nfilters, + filters_left); + set_expression_qualify_mode(action->expr, filters_left); + +} + +void +filter_syscall(struct tcb *tcp) +{ + unsigned int i; + + for (i = 0; i < nfilter_actions; ++i) + run_filter_action(tcp, &filter_actions[i]); +} + +void +set_filter_action_priv_data(struct filter_action *action, void *_priv_data) +{ + if (action) + action->_priv_data = _priv_data; +} diff --git a/filter_expression.c b/filter_expression.c new file mode 100644 index 00000000..73aaae3a --- /dev/null +++ b/filter_expression.c @@ -0,0 +1,281 @@ +/* + * Copyright (c) 2017 Nikolay Marchuk <marchuk.nikola...@gmail.com> + * 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 <stdarg.h> +#include "filter.h" + +struct expression_token { + enum token_type { + TOK_VARIABLE, + TOK_OPERATOR + } type; + union token_data { + unsigned int variable_id; + enum operator_type { + OP_NOT, + OP_AND, + OP_OR + } operator_id; + } data; +}; + +struct bool_expression { + unsigned int ntokens; + struct expression_token *tokens; +}; + +struct bool_expression * +create_expression(void) +{ + return xcalloc(1, sizeof(struct bool_expression)); +} + +static void +reallocate_expression(struct bool_expression *const expr, + const unsigned int new_ntokens) +{ + if (!expr) + error_msg_and_die("invalid expression"); + expr->tokens = xreallocarray(expr->tokens, new_ntokens, + sizeof(*expr->tokens)); + if (new_ntokens > expr->ntokens) + memset(expr->tokens + expr->ntokens, 0, + sizeof(*expr->tokens) * (new_ntokens - expr->ntokens)); + expr->ntokens = new_ntokens; +} + +static void +add_variable_token(struct bool_expression *expr, unsigned int id) +{ + struct expression_token token; + token.type = TOK_VARIABLE; + token.data.variable_id = id; + reallocate_expression(expr, expr->ntokens + 1); + expr->tokens[expr->ntokens - 1] = token; +} + +static void +add_operator_token(struct bool_expression *expr, int op) { + struct expression_token token; + token.type = TOK_OPERATOR; + token.data.operator_id = op; + reallocate_expression(expr, expr->ntokens + 1); + expr->tokens[expr->ntokens - 1] = token; +} + +void +expression_add_filter_and(struct bool_expression *expr, unsigned int filter_id) +{ + add_variable_token(expr, filter_id); + add_operator_token(expr, OP_AND); +} + +void +set_expression_qualify_mode(struct bool_expression *expr, + unsigned int filters_left) +{ + unsigned int i; + + if (!expr) + error_msg_and_die("invalid expression"); + reallocate_expression(expr, 2 * filters_left - 1); + for (i = 0; i < filters_left; ++i) { + expr->tokens[i].type = TOK_VARIABLE; + expr->tokens[i].data.variable_id = i; + } + for (; i < 2 * filters_left - 1; ++i) { + expr->tokens[i].type = TOK_OPERATOR; + expr->tokens[i].data.operator_id = OP_AND; + } +} + +ATTRIBUTE_FORMAT((printf, 3, 4)) +static int +printf_append(char **ptr, char *end, const char *fmt, ...) + { + int ret; + va_list args; + + va_start(args, fmt); + ret = vsnprintf(*ptr, end - *ptr, fmt, args); + va_end(args); + + if (ret < 0) + return ret; + + *ptr += MIN(ret, end - *ptr); + return ret; +} + +/* Print full diagnostics for corrupted expression */ +ATTRIBUTE_NORETURN +static void +handle_corrupted_expression(struct bool_expression *expr, bool *stack, + unsigned int stack_size, unsigned int current_pos, + bool *variables, unsigned int variables_num) +{ + char *buf, *pos, *end; + unsigned int buf_size; + unsigned int i; + + /* Calculate buffer size. */ + buf_size = sizeof("corrupted filter expression:"); + buf_size += sizeof("expression (ntokens = ):") + + 3 * sizeof(unsigned int) + + (sizeof("op_") + 3 * sizeof(int)) * expr->ntokens; + buf_size += sizeof("variables (nvariables = ):") + 3 * sizeof(int) + + sizeof("false") * variables_num; + buf_size += sizeof("current position: ") + 3 * sizeof(int); + buf_size += sizeof("stack (stack_size = ):") + 3 * sizeof(int) + + sizeof("false") * stack_size; + + buf = xcalloc(buf_size, 1); + pos = buf; + end = buf + buf_size; + + printf_append(&pos, end, "corrupted filter expression:\n"); + + /* Print expression. */ + printf_append(&pos, end, "expression (ntokens = %u):", expr->ntokens); + for (i = 0; i < expr->ntokens; ++i) { + switch (expr->tokens[i].type) { + case TOK_VARIABLE: + printf_append(&pos, end, " v_%u", + expr->tokens[i].data.variable_id); + break; + case TOK_OPERATOR: + switch (expr->tokens[i].data.operator_id) { + case OP_NOT: + printf_append(&pos, end, " not"); + break; + case OP_AND: + printf_append(&pos, end, " and"); + break; + case OP_OR: + printf_append(&pos, end, " or"); + break; + default: + printf_append(&pos, end, " op_%d", + expr->tokens[i].data.operator_id); + } + break; + default: + printf_append(&pos, end, " ?_%d", expr->tokens[i].type); + } + } + printf_append(&pos, end, "\n"); + + /* Print variables. */ + printf_append(&pos, end, "variables (nvariables = %u):", variables_num); + for (i = 0; i < variables_num; ++i) + printf_append(&pos, end, !variables[i] ? " false" : " true"); + printf_append(&pos, end, "\n"); + + printf_append(&pos, end, "current position: %u\n", current_pos); + + /* Print current stack state. */ + printf_append(&pos, end, "stack (stack_size = %u):", stack_size); + for (i = 0; i < stack_size; ++i) + printf_append(&pos, end, !stack[i] ? " false" : " true"); + + error_msg_and_die("%s", buf); +} + +#define MAX_STACK_SIZE 32 + +bool +run_expression(struct bool_expression *expr, bool *variables, + unsigned int variables_num) +{ + bool stack[MAX_STACK_SIZE]; + unsigned int stack_size = 0; + unsigned int i; + + for (i = 0; i < expr->ntokens; ++i) { + struct expression_token *tok = &expr->tokens[i]; + + switch (tok->type) { + case TOK_VARIABLE: + if (stack_size == MAX_STACK_SIZE) + handle_corrupted_expression(expr, stack, + stack_size, i, + variables, + variables_num); + + if (tok->data.variable_id >= variables_num) + handle_corrupted_expression(expr, stack, + stack_size, i, + variables, + variables_num); + stack[stack_size++] = variables[tok->data.variable_id]; + break; + case TOK_OPERATOR: + switch (tok->data.operator_id) { + case OP_NOT: + if (stack_size == 0) + handle_corrupted_expression(expr, stack, + stack_size, i, + variables, + variables_num); + stack[stack_size - 1] = !stack[stack_size - 1]; + break; + case OP_AND: + if (stack_size < 2) + handle_corrupted_expression(expr, stack, + stack_size, i, + variables, + variables_num); + stack[stack_size - 2] = stack[stack_size - 2] + && stack[stack_size - 1]; + --stack_size; + break; + case OP_OR: + if (stack_size < 2) + handle_corrupted_expression(expr, stack, + stack_size, i, + variables, + variables_num); + stack[stack_size - 2] = stack[stack_size - 2] + || stack[stack_size - 1]; + --stack_size; + break; + default: + handle_corrupted_expression(expr, stack, + stack_size, i, + variables, + variables_num); + } + break; + } + } + + if (stack_size != 1) + handle_corrupted_expression(expr, stack, stack_size, i, + variables, variables_num); + return stack[0]; +} diff --git a/filter_qualify.c b/filter_qualify.c index b59b19b9..f195743a 100644 --- a/filter_qualify.c +++ b/filter_qualify.c @@ -31,16 +31,8 @@ #include "number_set.h" #include "filter.h" -struct number_set *read_set; -struct number_set *write_set; struct number_set *signal_set; -static struct number_set *abbrev_set; -static struct number_set *inject_set; -static struct number_set *raw_set; -static struct number_set *trace_set; -static struct number_set *verbose_set; - static int sigstr_to_uint(const char *s) { @@ -149,46 +141,57 @@ parse_inject_token(const char *const token, struct inject_opts *const fopts, return true; } -static char * -parse_inject_expression(const char *const s, char **buf, - struct inject_opts *const fopts, - const bool fault_tokens_only) +void +parse_inject_common_args(char *str, struct inject_opts *const opts, + const bool fault_tokens_only, bool qualify_mode) { char *saveptr = NULL; - char *name = NULL; char *token; - - *buf = xstrdup(s); - for (token = strtok_r(*buf, ":", &saveptr); token; - token = strtok_r(NULL, ":", &saveptr)) { - if (!name) - name = token; - else if (!parse_inject_token(token, fopts, fault_tokens_only)) - goto parse_error; + const char *delim = qualify_mode ? ":" : ";"; + + opts->first = 1; + opts->step = 1; + opts->rval = INJECT_OPTS_RVAL_DEFAULT; + opts->signo = 0; + opts->init = false; + + for (token = strtok_r(str, delim, &saveptr); token; + token = strtok_r(NULL, delim, &saveptr)) { + if (!parse_inject_token(token, opts, fault_tokens_only)) + return; } - if (name) - return name; - -parse_error: - free(*buf); - return *buf = NULL; + /* If neither of retval, error, or signal is specified, then ... */ + if (opts->rval == INJECT_OPTS_RVAL_DEFAULT && !opts->signo) { + if (fault_tokens_only) { + /* in fault syntax the default error code is ENOSYS. */ + opts->rval = -ENOSYS; + } else { + /* in inject syntax this is not allowed. */ + return; + } + } + opts->init = true; } static void qualify_read(const char *const str) { - if (!read_set) - read_set = alloc_number_set_array(1); - qualify_tokens(str, read_set, string_to_uint, "descriptor"); + struct filter_action *action = find_or_add_action("read"); + struct filter *filter = create_filter(action, "fd"); + + parse_filter(filter, str); + set_qualify_mode(action, 1); } static void qualify_write(const char *const str) { - if (!write_set) - write_set = alloc_number_set_array(1); - qualify_tokens(str, write_set, string_to_uint, "descriptor"); + struct filter_action *action = find_or_add_action("write"); + struct filter *filter = create_filter(action, "fd"); + + parse_filter(filter, str); + set_qualify_mode(action, 1); } static void @@ -196,39 +199,49 @@ qualify_signals(const char *const str) { if (!signal_set) signal_set = alloc_number_set_array(1); + else + clear_number_set_array(signal_set, 1); qualify_tokens(str, signal_set, sigstr_to_uint, "signal"); } static void qualify_trace(const char *const str) { - if (!trace_set) - trace_set = alloc_number_set_array(SUPPORTED_PERSONALITIES); - qualify_syscall_tokens(str, trace_set, "system call"); + struct filter_action *action = find_or_add_action("trace"); + struct filter *filter = create_filter(action, "syscall"); + + parse_filter(filter, str); + set_qualify_mode(action, 1); } static void qualify_abbrev(const char *const str) { - if (!abbrev_set) - abbrev_set = alloc_number_set_array(SUPPORTED_PERSONALITIES); - qualify_syscall_tokens(str, abbrev_set, "system call"); + struct filter_action *action = find_or_add_action("abbrev"); + struct filter *filter = create_filter(action, "syscall"); + + parse_filter(filter, str); + set_qualify_mode(action, 1); } static void qualify_verbose(const char *const str) { - if (!verbose_set) - verbose_set = alloc_number_set_array(SUPPORTED_PERSONALITIES); - qualify_syscall_tokens(str, verbose_set, "system call"); + struct filter_action *action = find_or_add_action("verbose"); + struct filter *filter = create_filter(action, "syscall"); + + parse_filter(filter, str); + set_qualify_mode(action, 1); } static void qualify_raw(const char *const str) { - if (!raw_set) - raw_set = alloc_number_set_array(SUPPORTED_PERSONALITIES); - qualify_syscall_tokens(str, raw_set, "system call"); + struct filter_action *action = find_or_add_action("raw"); + struct filter *filter = create_filter(action, "syscall"); + + parse_filter(filter, str); + set_qualify_mode(action, 1); } static void @@ -236,75 +249,39 @@ qualify_inject_common(const char *const str, const bool fault_tokens_only, const char *const description) { - struct inject_opts opts = { - .first = 1, - .step = 1, - .rval = INJECT_OPTS_RVAL_DEFAULT, - .signo = 0 - }; - char *buf = NULL; - char *name = parse_inject_expression(str, &buf, &opts, fault_tokens_only); - if (!name) { - error_msg_and_die("invalid %s '%s'", description, str); - } - - /* If neither of retval, error, or signal is specified, then ... */ - if (opts.rval == INJECT_OPTS_RVAL_DEFAULT && !opts.signo) { - if (fault_tokens_only) { - /* in fault= syntax the default error code is ENOSYS. */ - opts.rval = -ENOSYS; - } else { - /* in inject= syntax this is not allowed. */ - error_msg_and_die("invalid %s '%s'", description, str); - } - } - - struct number_set *tmp_set = - alloc_number_set_array(SUPPORTED_PERSONALITIES); - qualify_syscall_tokens(name, tmp_set, description); - + struct inject_opts *opts = xmalloc(sizeof(struct inject_opts)); + char *buf = xstrdup(str); + struct filter_action *action; + struct filter *filter; + char *args = strchr(buf, ':'); + + if (args) + *(args++) = '\0'; + + action = find_or_add_action(fault_tokens_only ? "fault" : "inject"); + filter = create_filter(action, "syscall"); + parse_filter(filter, buf); + set_qualify_mode(action, 1); + parse_inject_common_args(args, opts, fault_tokens_only, true); + + if (!opts->init) + error_msg_and_die("invalid %s argument '%s'", description, + args ? args : ""); free(buf); - /* - * Initialize inject_vec accourding to tmp_set. - * Merge tmp_set into inject_set. - */ - unsigned int p; - for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) { - if (number_set_array_is_empty(tmp_set, p)) - continue; - - if (!inject_set) { - inject_set = - alloc_number_set_array(SUPPORTED_PERSONALITIES); - } - if (!inject_vec[p]) { - inject_vec[p] = xcalloc(nsyscall_vec[p], - sizeof(*inject_vec[p])); - } - - unsigned int i; - for (i = 0; i < nsyscall_vec[p]; ++i) { - if (is_number_in_set_array(i, tmp_set, p)) { - add_number_to_set_array(i, inject_set, p); - inject_vec[p][i] = opts; - } - } - } - - free_number_set_array(tmp_set, SUPPORTED_PERSONALITIES); + set_filter_action_priv_data(action, opts); } static void qualify_fault(const char *const str) { - qualify_inject_common(str, true, "fault argument"); + qualify_inject_common(str, true, "fault"); } static void qualify_inject(const char *const str) { - qualify_inject_common(str, false, "inject argument"); + qualify_inject_common(str, false, "inject"); } static const struct qual_options { @@ -352,18 +329,3 @@ qualify(const char *str) opt->qualify(str); } - -unsigned int -qual_flags(const unsigned int scno) -{ - return (is_number_in_set_array(scno, trace_set, current_personality) - ? QUAL_TRACE : 0) - | (is_number_in_set_array(scno, abbrev_set, current_personality) - ? QUAL_ABBREV : 0) - | (is_number_in_set_array(scno, verbose_set, current_personality) - ? QUAL_VERBOSE : 0) - | (is_number_in_set_array(scno, raw_set, current_personality) - ? QUAL_RAW : 0) - | (is_number_in_set_array(scno, inject_set, current_personality) - ? QUAL_INJECT : 0); -} diff --git a/number_set.h b/number_set.h index 967a1c88..5c17e803 100644 --- a/number_set.h +++ b/number_set.h @@ -57,8 +57,6 @@ alloc_number_set_array(unsigned int nmemb); extern void free_number_set_array(struct number_set *, unsigned int nmemb); -extern struct number_set *read_set; -extern struct number_set *write_set; extern struct number_set *signal_set; #endif /* !STRACE_NUMBER_SET_H */ diff --git a/pathtrace.c b/pathtrace.c index 52582380..23a352ef 100644 --- a/pathtrace.c +++ b/pathtrace.c @@ -91,7 +91,7 @@ storepath(const char *path, struct path_set *set) set->paths_selected = xreallocarray(set->paths_selected, set->num_selected, sizeof(set->paths_selected[0])); - set->paths_selected[i] = path; + set->paths_selected[i] = xstrdup(path); } /* diff --git a/strace.c b/strace.c index 6ed86a6f..3fa15a5c 100644 --- a/strace.c +++ b/strace.c @@ -771,7 +771,8 @@ droptcb(struct tcb *tcp) int p; for (p = 0; p < SUPPORTED_PERSONALITIES; ++p) - free(tcp->inject_vec[p]); + if (tcp->inject_vec[p]) + free(tcp->inject_vec[p]); free_tcb_priv_data(tcp); @@ -1713,6 +1714,7 @@ init(int argc, char *argv[]) break; } } + filtering_parsing_finish(); argv += optind; argc -= optind; @@ -2415,6 +2417,8 @@ trace_syscall(struct tcb *tcp, unsigned int *sig) case 0: return 0; case 1: + if (!tcp->qual_flg) + filter_syscall(tcp); res = syscall_entering_trace(tcp, sig); } syscall_entering_finish(tcp, res); diff --git a/syscall.c b/syscall.c index 6b1d2dcd..492858ca 100644 --- a/syscall.c +++ b/syscall.c @@ -346,7 +346,6 @@ decode_socket_subcall(struct tcb *tcp) return; tcp->scno = scno; - tcp->qual_flg = qual_flags(scno); tcp->s_ent = &sysent[scno]; unsigned int i; @@ -386,7 +385,6 @@ decode_ipc_subcall(struct tcb *tcp) } tcp->scno = SYS_ipc_subcall + call; - tcp->qual_flg = qual_flags(tcp->scno); tcp->s_ent = &sysent[tcp->scno]; const unsigned int n = tcp->s_ent->nargs; @@ -403,7 +401,6 @@ decode_mips_subcall(struct tcb *tcp) if (!scno_is_valid(tcp->u_arg[0])) return; tcp->scno = tcp->u_arg[0]; - tcp->qual_flg = qual_flags(tcp->scno); tcp->s_ent = &sysent[tcp->scno]; memmove(&tcp->u_arg[0], &tcp->u_arg[1], sizeof(tcp->u_arg) - sizeof(tcp->u_arg[0])); @@ -432,7 +429,7 @@ dumpio(struct tcb *tcp) if (fd < 0) return; - if (is_number_in_set(fd, read_set)) { + if (dump_read(tcp)) { switch (tcp->s_ent->sen) { case SEN_read: case SEN_pread: @@ -455,7 +452,7 @@ dumpio(struct tcb *tcp) return; } } - if (is_number_in_set(fd, write_set)) { + if (dump_write(tcp)) { switch (tcp->s_ent->sen) { case SEN_write: case SEN_pwrite: @@ -541,8 +538,6 @@ static void get_error(struct tcb *, const bool); static int arch_set_error(struct tcb *); static int arch_set_success(struct tcb *); -struct inject_opts *inject_vec[SUPPORTED_PERSONALITIES]; - static struct inject_opts * tcb_inject_opts(struct tcb *tcp) { @@ -554,14 +549,6 @@ tcb_inject_opts(struct tcb *tcp) static long tamper_with_syscall_entering(struct tcb *tcp, unsigned int *signo) { - if (!tcp->inject_vec[current_personality]) { - tcp->inject_vec[current_personality] = - xcalloc(nsyscalls, sizeof(**inject_vec)); - memcpy(tcp->inject_vec[current_personality], - inject_vec[current_personality], - nsyscalls * sizeof(**inject_vec)); - } - struct inject_opts *opts = tcb_inject_opts(tcp); if (!opts || opts->first == 0) @@ -1199,7 +1186,8 @@ get_scno(struct tcb *tcp) if (scno_is_valid(tcp->scno)) { tcp->s_ent = &sysent[tcp->scno]; - tcp->qual_flg = qual_flags(tcp->scno); + /* Clear qual_flg to distinguish valid syscall from printargs */ + tcp->qual_flg = 0; } else { struct sysent_buf *s = xcalloc(1, sizeof(*s)); -- 2.11.0 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Strace-devel mailing list Strace-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/strace-devel