Add support for star globbing patterns in event names

This patch adds support for full star-only globbing patterns used in
the event names (enabler names).

strutils_star_glob_match() is always used to perform the match when
the enabler is LTTNG_ENABLER_STAR_GLOB. This enabler is set when it is
detected that its name contains at least one non-escaped star with
strutils_is_star_glob_pattern().

While exclusions could be checked before the enabler name match to this
date, they must now be checked after we know there's a match because the
intersection of exclusion names and event event name is not always
checked on the LTTng-tools side (too much complexity for too little
gain).

The match itself is performed by strutils_star_glob_match(), the same
function that the filter interpreter uses.

Signed-off-by: Philippe Proulx <eeppeliteloop@gmail.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/include/lttng/ust-events.h b/include/lttng/ust-events.h
index 0b2291b3d8c76265a458a7e94a629a516d2ae080..6b7bd00e26e5915f5a5df74acc5b81bdc5a5ba99 100644 (file)
--- a/include/lttng/ust-events.h
+++ b/include/lttng/ust-events.h
@@ -342,7 +342,7 @@ struct lttng_probe_desc {
 /* Data structures used by the tracer. */
 
 enum lttng_enabler_type {
-       LTTNG_ENABLER_WILDCARD,
+       LTTNG_ENABLER_STAR_GLOB,
        LTTNG_ENABLER_EVENT,
 };
 

diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c
index 4c0e10910b29f40232b55b446626ef82c31c2bdd..fa54a025a967226b5527384c9217849e97ea1c83 100644 (file)
--- a/liblttng-ust/lttng-events.c
+++ b/liblttng-ust/lttng-events.c
@@ -33,6 +33,7 @@
 #include <stddef.h>
 #include <inttypes.h>
 #include <time.h>
+#include <stdbool.h>
 #include <lttng/ust-endian.h>
 #include "clock.h"
 
@@ -55,6 +56,7 @@
 #include "lttng-ust-uuid.h"
 
 #include "tracepoint-internal.h"
+#include "string-utils.h"
 #include "lttng-tracer.h"
 #include "lttng-tracer-core.h"
 #include "lttng-ust-statedump.h"
@@ -626,16 +628,15 @@ exist:
 }
 
 static
-int lttng_desc_match_wildcard_enabler(const struct lttng_event_desc *desc,
+int lttng_desc_match_star_glob_enabler(const struct lttng_event_desc *desc,
                struct lttng_enabler *enabler)
 {
        int loglevel = 0;
        unsigned int has_loglevel = 0;
 
-       assert(enabler->type == LTTNG_ENABLER_WILDCARD);
-       /* Compare excluding final '*' */
-       if (strncmp(desc->name, enabler->event_param.name,
-                       strlen(enabler->event_param.name) - 1))
+       assert(enabler->type == LTTNG_ENABLER_STAR_GLOB);
+       if (!strutils_star_glob_match(enabler->event_param.name, -1ULL,
+                       desc->name, -1ULL))
                return 0;
        if (desc->loglevel) {
                loglevel = *(*desc->loglevel);
@@ -675,34 +676,35 @@ static
 int lttng_desc_match_enabler(const struct lttng_event_desc *desc,
                struct lttng_enabler *enabler)
 {
-       struct lttng_ust_excluder_node *excluder;
-
-       /* If event matches with an excluder, return 'does not match' */
-       cds_list_for_each_entry(excluder, &enabler->excluder_head, node) {
-               int count;
-
-               for (count = 0; count < excluder->excluder.count; count++) {
-                       int found, len;
-                       char *excluder_name;
-
-                       excluder_name = (char *) (excluder->excluder.names)
-                                       + count * LTTNG_UST_SYM_NAME_LEN;
-                       len = strnlen(excluder_name, LTTNG_UST_SYM_NAME_LEN);
-                       if (len > 0 && excluder_name[len - 1] == '*') {
-                               found = !strncmp(desc->name, excluder_name,
-                                               len - 1);
-                       } else {
-                               found = !strncmp(desc->name, excluder_name,
-                                               LTTNG_UST_SYM_NAME_LEN - 1);
-                       }
-                       if (found) {
-                               return 0;
+       switch (enabler->type) {
+       case LTTNG_ENABLER_STAR_GLOB:
+       {
+               struct lttng_ust_excluder_node *excluder;
+
+               if (!lttng_desc_match_star_glob_enabler(desc, enabler)) {
+                       return 0;
+               }
+
+               /*
+                * If the matching event matches with an excluder,
+                * return 'does not match'
+                */
+               cds_list_for_each_entry(excluder, &enabler->excluder_head, node) {
+                       int count;
+
+                       for (count = 0; count < excluder->excluder.count; count++) {
+                               int len;
+                               char *excluder_name;
+
+                               excluder_name = (char *) (excluder->excluder.names)
+                                               + count * LTTNG_UST_SYM_NAME_LEN;
+                               len = strnlen(excluder_name, LTTNG_UST_SYM_NAME_LEN);
+                               if (len > 0 && strutils_star_glob_match(excluder_name, len, desc->name, -1ULL))
+                                       return 0;
                        }
                }
+               return 1;
        }
-       switch (enabler->type) {
-       case LTTNG_ENABLER_WILDCARD:
-               return lttng_desc_match_wildcard_enabler(desc, enabler);
        case LTTNG_ENABLER_EVENT:
                return lttng_desc_match_event_enabler(desc, enabler);
        default:

diff --git a/liblttng-ust/lttng-ust-abi.c b/liblttng-ust/lttng-ust-abi.c
index 4fbf15c6543aeb55faf8e433eb2a9fedd6fdc9f3..24769a7d6571f5fe49ea90ab4f1dcc7443b822ba 100644 (file)
--- a/liblttng-ust/lttng-ust-abi.c
+++ b/liblttng-ust/lttng-ust-abi.c
@@ -50,6 +50,7 @@
 #include <usterr-signal-safe.h>
 #include <helper.h>
 #include "lttng-tracer.h"
+#include "string-utils.h"
 #include "../libringbuffer/shm.h"
 #include "../libringbuffer/frontend_types.h"
 
@@ -210,7 +211,7 @@ int lttng_ust_objd_unref(int id, int is_owner)
        }
        if ((--obj->u.s.f_count) == 1) {
                const struct lttng_ust_objd_ops *ops = objd_ops(id);
-               
+
                if (ops->release)
                        ops->release(id);
                objd_free(id);
@@ -880,10 +881,14 @@ long lttng_channel_cmd(int objd, unsigned int cmd, unsigned long arg,
        {
                struct lttng_ust_event *event_param =
                        (struct lttng_ust_event *) arg;
-               if (event_param->name[strlen(event_param->name) - 1] == '*') {
-                       /* If ends with wildcard, create wildcard. */
+
+               if (strutils_is_star_glob_pattern(event_param->name)) {
+                       /*
+                        * If the event name is a star globbing pattern,
+                        * we create the special star globbing enabler.
+                        */
                        return lttng_abi_create_enabler(objd, event_param,
-                                       owner, LTTNG_ENABLER_WILDCARD);
+                                       owner, LTTNG_ENABLER_STAR_GLOB);
                } else {
                        return lttng_abi_create_enabler(objd, event_param,
                                        owner, LTTNG_ENABLER_EVENT);