From: Jonathan Rajotte Date: Wed, 11 Mar 2020 17:55:16 +0000 (-0400) Subject: event-rule: introduce event rule syscall X-Git-Tag: v2.13.0-rc1~473 X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=e6a39346997db7e1d40026b2cc10be5893723eb3;p=lttng-tools.git event-rule: introduce event rule syscall This is the "--syscall" option of the enable-event command line. Signed-off-by: Jonathan Rajotte Signed-off-by: Jérémie Galarneau Change-Id: I9c36cb0440e1f26a3b436782eb437a8ddffbe4fa --- diff --git a/include/Makefile.am b/include/Makefile.am index 3ba967e0a..92b5c75bd 100644 --- a/include/Makefile.am +++ b/include/Makefile.am @@ -145,7 +145,8 @@ lttngtriggerinclude_HEADERS= \ lttngeventruleinclude_HEADERS= \ lttng/event-rule/event-rule.h \ - lttng/event-rule/kprobe.h + lttng/event-rule/kprobe.h \ + lttng/event-rule/syscall.h noinst_HEADERS = \ lttng/snapshot-internal.h \ @@ -179,5 +180,6 @@ noinst_HEADERS = \ lttng/kernel-probe-internal.h \ lttng/event-rule/event-rule-internal.h \ lttng/event-rule/kprobe-internal.h \ + lttng/event-rule/syscall-internal.h \ version.h \ version.i diff --git a/include/lttng/event-rule/syscall-internal.h b/include/lttng/event-rule/syscall-internal.h new file mode 100644 index 000000000..e99b69ae4 --- /dev/null +++ b/include/lttng/event-rule/syscall-internal.h @@ -0,0 +1,46 @@ +/* + * Copyright (C) 2019 Jonathan Rajotte + * + * SPDX-License-Identifier: LGPL-2.1-only + * + */ + +#ifndef LTTNG_EVENT_RULE_SYSCALL_INTERNAL_H +#define LTTNG_EVENT_RULE_SYSCALL_INTERNAL_H + +#include +#include +#include +#include + +struct lttng_event_rule_syscall { + struct lttng_event_rule parent; + char *pattern; + char *filter_expression; + + /* Internal use only. */ + struct { + char *filter; + struct lttng_filter_bytecode *bytecode; + } internal_filter; +}; + +struct lttng_event_rule_syscall_comm { + /* Includes terminator `\0`. */ + uint32_t pattern_len; + /* Includes terminator `\0`. */ + uint32_t filter_expression_len; + /* + * Payload is composed of, in that order: + * - Pattern (null terminated), + * - Filter expression (null terminated). + */ + char payload[]; +} LTTNG_PACKED; + +LTTNG_HIDDEN +ssize_t lttng_event_rule_syscall_create_from_payload( + struct lttng_payload_view *view, + struct lttng_event_rule **rule); + +#endif /* LTTNG_EVENT_RULE_SYSCALL_INTERNAL_H */ diff --git a/include/lttng/event-rule/syscall.h b/include/lttng/event-rule/syscall.h new file mode 100644 index 000000000..baf8432c1 --- /dev/null +++ b/include/lttng/event-rule/syscall.h @@ -0,0 +1,83 @@ +/* + * Copyright (C) 2019 Jonathan Rajotte + * + * SPDX-License-Identifier: LGPL-2.1-only + * + */ + +#ifndef LTTNG_EVENT_RULE_SYSCALL_H +#define LTTNG_EVENT_RULE_SYSCALL_H + +#include + +#ifdef __cplusplus +extern "C" { +#endif + +/* + * Create a newly allocated syscall event rule. + * + * Returns a new event rule on success, NULL on failure. This event rule must be + * destroyed using lttng_event_rule_destroy(). + */ +extern struct lttng_event_rule *lttng_event_rule_syscall_create(void); + +/* + * Set the pattern of a syscall event rule. + * + * Pattern can contain wildcard '*'. See man lttng-enable-event. + * + * The pattern is copied internally. + * + * Returns LTTNG_EVENT_RULE_STATUS_OK on success, LTTNG_EVENT_RULE_STATUS_INVALID + * if invalid parameters are passed. + */ +extern enum lttng_event_rule_status lttng_event_rule_syscall_set_pattern( + struct lttng_event_rule *rule, const char *pattern); + +/* + * Get the pattern of a syscall event rule. + * + * The caller does not assume the ownership of the returned pattern. The + * pattern shall only only be used for the duration of the event rule's + * lifetime, or before a different pattern is set. + * + * Returns LTTNG_EVENT_RULE_STATUS_OK and a pointer to the event rule's pattern + * on success, LTTNG_EVENT_RULE_STATUS_INVALID if an invalid + * parameter is passed, or LTTNG_EVENT_RULE_STATUS_UNSET if a pattern + * was not set prior to this call. + */ +extern enum lttng_event_rule_status lttng_event_rule_syscall_get_pattern( + const struct lttng_event_rule *rule, const char **pattern); + +/* + * Set the filter expression of a syscall event rule. + * + * The expression is copied internally. + * + * Returns LTTNG_EVENT_RULE_STATUS_OK on success, LTTNG_EVENT_RULE_STATUS_INVALID + * if invalid parameters are passed. + */ +extern enum lttng_event_rule_status lttng_event_rule_syscall_set_filter( + struct lttng_event_rule *rule, const char *expression); + +/* + * Get the filter expression of a syscall event rule. + * + * The caller does not assume the ownership of the returned filter expression. + * The filter expression shall only only be used for the duration of the event + * rule's lifetime, or before a different filter expression is set. + * + * Returns LTTNG_EVENT_RULE_STATUS_OK and a pointer to the event rule's filter + * expression on success, LTTNG_EVENT_RULE_STATUS_INVALID if an invalid + * parameter is passed, or LTTNG_EVENT_RULE_STATUS_UNSET if a filter expression + * was not set prior to this call. + */ +extern enum lttng_event_rule_status lttng_event_rule_syscall_get_filter( + const struct lttng_event_rule *rule, const char **expression); + +#ifdef __cplusplus +} +#endif + +#endif /* LTTNG_EVENT_RULE_SYSCALL_H */ diff --git a/include/lttng/lttng.h b/include/lttng/lttng.h index a7fef39c3..8686643b8 100644 --- a/include/lttng/lttng.h +++ b/include/lttng/lttng.h @@ -36,6 +36,7 @@ #include #include #include +#include #include #include #include diff --git a/src/common/Makefile.am b/src/common/Makefile.am index b31e6c546..556c55777 100644 --- a/src/common/Makefile.am +++ b/src/common/Makefile.am @@ -50,6 +50,7 @@ libcommon_la_SOURCES = \ event.c \ event-rule/event-rule.c \ event-rule/kprobe.c \ + event-rule/syscall.c \ filter.c filter.h \ fd-handle.c fd-handle.h \ fs-handle.c fs-handle.h fs-handle-internal.h \ diff --git a/src/common/event-rule/event-rule.c b/src/common/event-rule/event-rule.c index e5736d6f9..707011586 100644 --- a/src/common/event-rule/event-rule.c +++ b/src/common/event-rule/event-rule.c @@ -13,6 +13,7 @@ #include #include #include +#include #include enum lttng_event_rule_type lttng_event_rule_get_type( @@ -165,7 +166,8 @@ ssize_t lttng_event_rule_create_from_payload( /* TODO */ break; case LTTNG_EVENT_RULE_TYPE_SYSCALL: - /* TODO */ + create_from_payload = + lttng_event_rule_syscall_create_from_payload; break; default: ERR("Attempted to create event rule of unknown type (%i)", diff --git a/src/common/event-rule/syscall.c b/src/common/event-rule/syscall.c new file mode 100644 index 000000000..ef7ccd0f9 --- /dev/null +++ b/src/common/event-rule/syscall.c @@ -0,0 +1,468 @@ +/* + * Copyright (C) 2019 Jonathan Rajotte + * + * SPDX-License-Identifier: LGPL-2.1-only + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define IS_SYSCALL_EVENT_RULE(rule) \ + (lttng_event_rule_get_type(rule) == LTTNG_EVENT_RULE_TYPE_SYSCALL) + +static void lttng_event_rule_syscall_destroy(struct lttng_event_rule *rule) +{ + struct lttng_event_rule_syscall *syscall; + + if (rule == NULL) { + return; + } + + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + + free(syscall->pattern); + free(syscall->filter_expression); + free(syscall->internal_filter.filter); + free(syscall->internal_filter.bytecode); + free(syscall); +} + +static bool lttng_event_rule_syscall_validate( + const struct lttng_event_rule *rule) +{ + bool valid = false; + struct lttng_event_rule_syscall *syscall; + + if (!rule) { + goto end; + } + + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + + /* Required field. */ + if (!syscall->pattern) { + ERR("Invalid syscall event rule: a pattern must be set."); + goto end; + } + + valid = true; +end: + return valid; +} + +static int lttng_event_rule_syscall_serialize( + const struct lttng_event_rule *rule, + struct lttng_payload *payload) +{ + int ret; + size_t pattern_len, filter_expression_len; + struct lttng_event_rule_syscall *syscall; + struct lttng_event_rule_syscall_comm syscall_comm; + + if (!rule || !IS_SYSCALL_EVENT_RULE(rule)) { + ret = -1; + goto end; + } + + DBG("Serializing syscall event rule"); + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + + pattern_len = strlen(syscall->pattern) + 1; + + if (syscall->filter_expression != NULL) { + filter_expression_len = strlen(syscall->filter_expression) + 1; + } else { + filter_expression_len = 0; + } + + syscall_comm.pattern_len = pattern_len; + syscall_comm.filter_expression_len = filter_expression_len; + + ret = lttng_dynamic_buffer_append( + &payload->buffer, &syscall_comm, sizeof(syscall_comm)); + if (ret) { + goto end; + } + + ret = lttng_dynamic_buffer_append( + &payload->buffer, syscall->pattern, pattern_len); + if (ret) { + goto end; + } + + ret = lttng_dynamic_buffer_append(&payload->buffer, + syscall->filter_expression, filter_expression_len); +end: + return ret; +} + +static bool lttng_event_rule_syscall_is_equal(const struct lttng_event_rule *_a, + const struct lttng_event_rule *_b) +{ + bool is_equal = false; + struct lttng_event_rule_syscall *a, *b; + + a = container_of(_a, struct lttng_event_rule_syscall, parent); + b = container_of(_b, struct lttng_event_rule_syscall, parent); + + if (!!a->filter_expression != !!b->filter_expression) { + goto end; + } + + assert(a->pattern); + assert(b->pattern); + if (strcmp(a->pattern, b->pattern)) { + goto end; + } + + if (a->filter_expression && b->filter_expression) { + if (strcmp(a->filter_expression, b->filter_expression)) { + goto end; + } + } else if (!!a->filter_expression != !!b->filter_expression) { + /* One is set and not the other. */ + goto end; + } + + is_equal = true; +end: + return is_equal; +} + +static enum lttng_error_code lttng_event_rule_syscall_generate_filter_bytecode( + struct lttng_event_rule *rule, uid_t uid, gid_t gid) +{ + int ret; + enum lttng_error_code ret_code = LTTNG_OK; + struct lttng_event_rule_syscall *syscall; + enum lttng_event_rule_status status; + const char *filter; + struct lttng_filter_bytecode *bytecode = NULL; + + assert(rule); + + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + + /* Generate the filter bytecode. */ + status = lttng_event_rule_syscall_get_filter(rule, &filter); + if (status == LTTNG_EVENT_RULE_STATUS_UNSET) { + filter = NULL; + } else if (status != LTTNG_EVENT_RULE_STATUS_OK) { + ret_code = LTTNG_ERR_FILTER_INVAL; + goto end; + } + + if (filter && filter[0] == '\0') { + ret_code = LTTNG_ERR_FILTER_INVAL; + goto end; + } + + if (filter == NULL) { + /* Nothing to do. */ + ret = LTTNG_OK; + goto end; + } + + syscall->internal_filter.filter = strdup(filter); + if (syscall->internal_filter.filter == NULL) { + ret_code = LTTNG_ERR_NOMEM; + goto end; + } + + ret = run_as_generate_filter_bytecode( + syscall->internal_filter.filter, uid, gid, &bytecode); + if (ret) { + ret_code = LTTNG_ERR_FILTER_INVAL; + } + + syscall->internal_filter.bytecode = bytecode; + bytecode = NULL; + +end: + free(bytecode); + return ret_code; +} + +static const char *lttng_event_rule_syscall_get_internal_filter( + const struct lttng_event_rule *rule) +{ + struct lttng_event_rule_syscall *syscall; + + assert(rule); + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + + return syscall->internal_filter.filter; +} + +static const struct lttng_filter_bytecode * +lttng_event_rule_syscall_get_internal_filter_bytecode( + const struct lttng_event_rule *rule) +{ + struct lttng_event_rule_syscall *syscall; + + assert(rule); + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + + return syscall->internal_filter.bytecode; +} + +static struct lttng_event_exclusion * +lttng_event_rule_syscall_generate_exclusions( + const struct lttng_event_rule *rule) +{ + /* Not supported. */ + return NULL; +} + +struct lttng_event_rule *lttng_event_rule_syscall_create() +{ + struct lttng_event_rule *rule = NULL; + struct lttng_event_rule_syscall *syscall_rule; + + syscall_rule = zmalloc(sizeof(struct lttng_event_rule_syscall)); + if (!syscall_rule) { + goto end; + } + + rule = &syscall_rule->parent; + lttng_event_rule_init( + &syscall_rule->parent, LTTNG_EVENT_RULE_TYPE_SYSCALL); + syscall_rule->parent.validate = lttng_event_rule_syscall_validate; + syscall_rule->parent.serialize = lttng_event_rule_syscall_serialize; + syscall_rule->parent.equal = lttng_event_rule_syscall_is_equal; + syscall_rule->parent.destroy = lttng_event_rule_syscall_destroy; + syscall_rule->parent.generate_filter_bytecode = + lttng_event_rule_syscall_generate_filter_bytecode; + syscall_rule->parent.get_filter = + lttng_event_rule_syscall_get_internal_filter; + syscall_rule->parent.get_filter_bytecode = + lttng_event_rule_syscall_get_internal_filter_bytecode; + syscall_rule->parent.generate_exclusions = + lttng_event_rule_syscall_generate_exclusions; +end: + return rule; +} + +LTTNG_HIDDEN +ssize_t lttng_event_rule_syscall_create_from_payload( + struct lttng_payload_view *view, + struct lttng_event_rule **_event_rule) +{ + ssize_t ret, offset = 0; + enum lttng_event_rule_status status; + const struct lttng_event_rule_syscall_comm *syscall_comm; + const char *pattern; + const char *filter_expression = NULL; + struct lttng_buffer_view current_buffer_view; + struct lttng_event_rule *rule = NULL; + + if (!_event_rule) { + ret = -1; + goto end; + } + + if (view->buffer.size < sizeof(*syscall_comm)) { + ERR("Failed to initialize from malformed event rule syscall: buffer too short to contain header"); + ret = -1; + goto end; + } + + current_buffer_view = lttng_buffer_view_from_view( + &view->buffer, offset, sizeof(*syscall_comm)); + syscall_comm = (typeof(syscall_comm)) current_buffer_view.data; + + if (!syscall_comm) { + ret = -1; + goto end; + } + + rule = lttng_event_rule_syscall_create(); + if (!rule) { + ERR("Failed to create event rule syscall"); + ret = -1; + goto end; + } + + /* Skip to payload. */ + offset += current_buffer_view.size; + + /* Map the pattern. */ + current_buffer_view = lttng_buffer_view_from_view( + &view->buffer, offset, syscall_comm->pattern_len); + pattern = current_buffer_view.data; + if (!pattern) { + ret = -1; + goto end; + } + + if (!lttng_buffer_view_contains_string(¤t_buffer_view, pattern, + syscall_comm->pattern_len)) { + ret = -1; + goto end; + } + + /* Skip after the pattern. */ + offset += syscall_comm->pattern_len; + + if (!syscall_comm->filter_expression_len) { + goto skip_filter_expression; + } + + /* Map the filter_expression. */ + current_buffer_view = lttng_buffer_view_from_view(&view->buffer, offset, + syscall_comm->filter_expression_len); + filter_expression = current_buffer_view.data; + if (!filter_expression) { + ret = -1; + goto end; + } + + if (!lttng_buffer_view_contains_string(¤t_buffer_view, + filter_expression, + syscall_comm->filter_expression_len)) { + ret = -1; + goto end; + } + + /* Skip after the pattern. */ + offset += syscall_comm->filter_expression_len; + +skip_filter_expression: + + status = lttng_event_rule_syscall_set_pattern(rule, pattern); + if (status != LTTNG_EVENT_RULE_STATUS_OK) { + ERR("Failed to set event rule syscall pattern"); + ret = -1; + goto end; + } + + if (filter_expression) { + status = lttng_event_rule_syscall_set_filter( + rule, filter_expression); + if (status != LTTNG_EVENT_RULE_STATUS_OK) { + ERR("Failed to set event rule syscall pattern"); + ret = -1; + goto end; + } + } + + *_event_rule = rule; + rule = NULL; + ret = offset; +end: + lttng_event_rule_destroy(rule); + return ret; +} + +enum lttng_event_rule_status lttng_event_rule_syscall_set_pattern( + struct lttng_event_rule *rule, const char *pattern) +{ + char *pattern_copy = NULL; + struct lttng_event_rule_syscall *syscall; + enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; + + if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !pattern || + strlen(pattern) == 0) { + status = LTTNG_EVENT_RULE_STATUS_INVALID; + goto end; + } + + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + pattern_copy = strdup(pattern); + if (!pattern_copy) { + status = LTTNG_EVENT_RULE_STATUS_ERROR; + goto end; + } + + if (syscall->pattern) { + free(syscall->pattern); + } + + syscall->pattern = pattern_copy; + pattern_copy = NULL; +end: + return status; +} + +enum lttng_event_rule_status lttng_event_rule_syscall_get_pattern( + const struct lttng_event_rule *rule, const char **pattern) +{ + struct lttng_event_rule_syscall *syscall; + enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; + + if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !pattern) { + status = LTTNG_EVENT_RULE_STATUS_INVALID; + goto end; + } + + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + if (!syscall->pattern) { + status = LTTNG_EVENT_RULE_STATUS_UNSET; + goto end; + } + + *pattern = syscall->pattern; +end: + return status; +} + +enum lttng_event_rule_status lttng_event_rule_syscall_set_filter( + struct lttng_event_rule *rule, const char *expression) +{ + char *expression_copy = NULL; + struct lttng_event_rule_syscall *syscall; + enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; + + /* TODO: validate that the passed expression is valid. */ + + if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !expression || + strlen(expression) == 0) { + status = LTTNG_EVENT_RULE_STATUS_INVALID; + goto end; + } + + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + expression_copy = strdup(expression); + if (!expression_copy) { + status = LTTNG_EVENT_RULE_STATUS_ERROR; + goto end; + } + + if (syscall->filter_expression) { + free(syscall->filter_expression); + } + + syscall->filter_expression = expression_copy; + expression_copy = NULL; +end: + return status; +} + +enum lttng_event_rule_status lttng_event_rule_syscall_get_filter( + const struct lttng_event_rule *rule, const char **expression) +{ + struct lttng_event_rule_syscall *syscall; + enum lttng_event_rule_status status = LTTNG_EVENT_RULE_STATUS_OK; + + if (!rule || !IS_SYSCALL_EVENT_RULE(rule) || !expression) { + status = LTTNG_EVENT_RULE_STATUS_INVALID; + goto end; + } + + syscall = container_of(rule, struct lttng_event_rule_syscall, parent); + if (!syscall->filter_expression) { + status = LTTNG_EVENT_RULE_STATUS_UNSET; + goto end; + } + + *expression = syscall->filter_expression; +end: + return status; +}