kdbus: generare bloom filters properly for messages we send

6 files changed, 222 insertions, 12 deletions

diff --git a/src/libsystemd-bus/bus-bloom.c b/src/libsystemd-bus/bus-bloom.c
new file mode 100644
index 0000000000..cb65e47b4c
--- /dev/null
+++ b/src/libsystemd-bus/bus-bloom.c
@@ -0,0 +1,93 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "util.h"
+#include "MurmurHash3.h"
+
+#include "bus-bloom.h"
+
+static inline void set_bit(uint64_t filter[], unsigned b) {
+        filter[b >> 6] |= 1ULL << (b & 63);
+}
+
+void bloom_add_data(uint64_t filter[BLOOM_SIZE/8], const void *data, size_t n) {
+        uint16_t hash[8];
+        unsigned k = 0;
+
+        /*
+         * Our bloom filter has the following parameters:
+         *
+         * m=512   (bits in the filter)
+         * k=8     (hash functions)
+         *
+         * We calculate a single 128bit MurmurHash value of which we
+         * use 8 parts of 9 bits as individual hash functions.
+         *
+         */
+
+        MurmurHash3_x64_128(data, n, 0, hash);
+
+        assert_cc(BLOOM_SIZE*8 == 512);
+
+        for (k = 0; k < ELEMENTSOF(hash); k++)
+                set_bit(filter, hash[k] & 511);
+}
+
+void bloom_add_pair(uint64_t filter[BLOOM_SIZE/8], const char *a, const char *b) {
+        size_t n;
+        char *c;
+
+        assert(filter);
+        assert(a);
+        assert(b);
+
+        n = strlen(a) + 1 + strlen(b);
+        c = alloca(n + 1);
+        strcpy(stpcpy(stpcpy(c, a), ":"), b);
+
+        bloom_add_data(filter, c, n);
+}
+
+void bloom_add_prefixes(uint64_t filter[BLOOM_SIZE/8], const char *a, const char *b, char sep) {
+        size_t n;
+        char *c, *p;
+
+        assert(filter);
+        assert(a);
+        assert(b);
+
+        n = strlen(a) + 1 + strlen(b);
+        c = alloca(n + 1);
+
+        p = stpcpy(stpcpy(c, a), ":");
+        strcpy(p, b);
+
+        for (;;) {
+                char *e;
+
+                e = strrchr(p, sep);
+                if (!e || e == p)
+                        break;
+
+                *e = 0;
+                bloom_add_data(filter, c, e - c);
+        }
+}
diff --git a/src/libsystemd-bus/bus-bloom.h b/src/libsystemd-bus/bus-bloom.h
new file mode 100644
index 0000000000..1bf14a3331
--- /dev/null
+++ b/src/libsystemd-bus/bus-bloom.h
@@ -0,0 +1,30 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <sys/types.h>
+
+#define BLOOM_SIZE 64
+
+void bloom_add_data(uint64_t filter[BLOOM_SIZE/8], const void *data, size_t n);
+void bloom_add_pair(uint64_t filter[BLOOM_SIZE/8], const char *a, const char *b);
+void bloom_add_prefixes(uint64_t filter[BLOOM_SIZE/8], const char *a, const char *b, char sep);
diff --git a/src/libsystemd-bus/bus-internal.c b/src/libsystemd-bus/bus-internal.c
index 3271354600..0e66f3d355 100644
--- a/src/libsystemd-bus/bus-internal.c
+++ b/src/libsystemd-bus/bus-internal.c
@@ -241,3 +241,16 @@ int bus_message_type_from_string(const char *s, uint8_t *u) {
 
         return 0;
 }
+
+const char *bus_message_type_to_string(uint8_t u) {
+        if (u == SD_BUS_MESSAGE_TYPE_SIGNAL)
+                return "signal";
+        else if (u == SD_BUS_MESSAGE_TYPE_METHOD_CALL)
+                return "method_call";
+        else if (u == SD_BUS_MESSAGE_TYPE_METHOD_ERROR)
+                return "error";
+        else if (u == SD_BUS_MESSAGE_TYPE_METHOD_RETURN)
+                 return "method_return";
+        else
+                return NULL;
+}
diff --git a/src/libsystemd-bus/bus-internal.h b/src/libsystemd-bus/bus-internal.h
index 9a118f8a21..4babfac86d 100644
--- a/src/libsystemd-bus/bus-internal.h
+++ b/src/libsystemd-bus/bus-internal.h
@@ -150,8 +150,6 @@ struct sd_bus {
 
         uint64_t hello_serial;
         unsigned iteration_counter;
-
-        uint64_t bloom_size;
 };
 
 static inline void bus_unrefp(sd_bus **b) {
@@ -191,6 +189,7 @@ bool namespace_simple_pattern(const char *pattern, const char *value);
 bool path_simple_pattern(const char *pattern, const char *value);
 
 int bus_message_type_from_string(const char *s, uint8_t *u);
+const char *bus_message_type_to_string(uint8_t u);
 
 #define error_name_is_valid interface_name_is_valid
 
diff --git a/src/libsystemd-bus/bus-kernel.c b/src/libsystemd-bus/bus-kernel.c
index 264c6994d9..f36f60e496 100644
--- a/src/libsystemd-bus/bus-kernel.c
+++ b/src/libsystemd-bus/bus-kernel.c
@@ -30,6 +30,7 @@
 #include "bus-internal.h"
 #include "bus-message.h"
 #include "bus-kernel.h"
+#include "bus-bloom.h"
 
 #define KDBUS_MSG_FOREACH_DATA(d, k)                                    \
         for ((d) = (k)->data;                                           \
@@ -80,17 +81,83 @@ static void append_destination(struct kdbus_msg_data **d, const char *s, size_t
         *d = (struct kdbus_msg_data*) ((uint8_t*) *d + (*d)->size);
 }
 
-static void append_bloom(struct kdbus_msg_data **d, const void *p, size_t length) {
+static void* append_bloom(struct kdbus_msg_data **d, size_t length) {
+        void *r;
+
         assert(d);
-        assert(p);
 
         *d = ALIGN8_PTR(*d);
 
         (*d)->size = offsetof(struct kdbus_msg_data, data) + length;
         (*d)->type = KDBUS_MSG_BLOOM;
-        memcpy((*d)->data, p, length);
+        r = (*d)->data;
 
         *d = (struct kdbus_msg_data*) ((uint8_t*) *d + (*d)->size);
+
+        return r;
+}
+
+static int bus_message_setup_bloom(sd_bus_message *m, void *bloom) {
+        unsigned i;
+        int r;
+
+        assert(m);
+        assert(bloom);
+
+        memset(bloom, 0, BLOOM_SIZE);
+
+        bloom_add_pair(bloom, "message-type", bus_message_type_to_string(m->header->type));
+
+        if (m->interface)
+                bloom_add_pair(bloom, "interface", m->interface);
+        if (m->member)
+                bloom_add_pair(bloom, "member", m->member);
+        if (m->path) {
+                bloom_add_pair(bloom, "path", m->path);
+                bloom_add_prefixes(bloom, "path-slash-prefix", m->path, '/');
+        }
+
+        r = sd_bus_message_rewind(m, true);
+        if (r < 0)
+                return r;
+
+        for (i = 0; i < 64; i++) {
+                char type;
+                const char *t;
+                char buf[sizeof("arg")-1 + 2 + sizeof("-slash-prefix")];
+                char *e;
+
+                r = sd_bus_message_peek_type(m, &type, NULL);
+                if (r < 0)
+                        return r;
+
+                if (type != SD_BUS_TYPE_STRING &&
+                    type != SD_BUS_TYPE_OBJECT_PATH &&
+                    type != SD_BUS_TYPE_SIGNATURE)
+                        break;
+
+                r = sd_bus_message_read_basic(m, type, &t);
+                if (r < 0)
+                        return r;
+
+                e = stpcpy(buf, "arg");
+                if (i < 10)
+                        *(e++) = '0' + i;
+                else {
+                        *(e++) = '0' + (i / 10);
+                        *(e++) = '0' + (i % 10);
+                }
+
+                *e = 0;
+                bloom_add_pair(bloom, buf, t);
+
+                strcpy(e, "-dot-prefix");
+                bloom_add_prefixes(bloom, buf, t, '.');
+                strcpy(e, "-slash-prefix");
+                bloom_add_prefixes(bloom, buf, t, '/');
+        }
+
+        return 0;
 }
 
 static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
@@ -122,7 +189,7 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
         sz += 3 * ALIGN8(offsetof(struct kdbus_msg_data, vec) + sizeof(struct kdbus_vec));
 
         /* Add space for bloom filter */
-        sz += ALIGN8(offsetof(struct kdbus_msg_data, data) + b->bloom_size);
+        sz += ALIGN8(offsetof(struct kdbus_msg_data, data) + BLOOM_SIZE);
 
         /* Add in well-known destination header */
         if (well_known) {
@@ -164,9 +231,13 @@ static int bus_message_setup_kmsg(sd_bus *b, sd_bus_message *m) {
                 void *p;
 
                 /* For now, let's add a mask all bloom filter */
-                p = alloca(b->bloom_size);
-                memset(p, 0xFF, b->bloom_size);
-                append_bloom(&d, p, b->bloom_size);
+                p = append_bloom(&d, BLOOM_SIZE);
+                r = bus_message_setup_bloom(m, p);
+                if (r < 0) {
+                        free(m->kdbus);
+                        m->kdbus = NULL;
+                        return -r;
+                }
         }
 
         m->kdbus->size = (uint8_t*) d - (uint8_t*) m->kdbus;
@@ -207,10 +278,12 @@ int bus_kernel_take_fd(sd_bus *b) {
             hello.conn_flags > 0xFFFFFFFFULL)
                 return -ENOTSUP;
 
+        if (hello.bloom_size != BLOOM_SIZE)
+                return -ENOTSUP;
+
         if (asprintf(&b->unique_name, ":1.%llu", (unsigned long long) hello.id) < 0)
                 return -ENOMEM;
 
-        b->bloom_size = hello.bloom_size;
         b->is_kernel = true;
         b->bus_client = true;
 
@@ -479,7 +552,9 @@ int bus_kernel_create(const char *name, char **s) {
         make->size = offsetof(struct kdbus_cmd_bus_make, name) + strlen(make->name) + 1;
         make->flags = KDBUS_ACCESS_WORLD | KDBUS_POLICY_OPEN;
         make->bus_flags = 0;
-        make->bloom_size = 16;
+        make->bloom_size = BLOOM_SIZE;
+
+        assert_cc(BLOOM_SIZE % 8 == 0);
 
         p = strjoin("/dev/kdbus/", make->name, "/bus", NULL);
         if (!p)
diff --git a/src/libsystemd-bus/test-bus-kernel.c b/src/libsystemd-bus/test-bus-kernel.c
index 2164daf690..5a5d9fc252 100644
--- a/src/libsystemd-bus/test-bus-kernel.c
+++ b/src/libsystemd-bus/test-bus-kernel.c
@@ -71,7 +71,7 @@ int main(int argc, char *argv[]) {
 
         printf("unique b: %s\n", ub);
 
-        r = sd_bus_emit_signal(a, "/foo", "waldo.com", "Piep", "s", "I am a string");
+        r = sd_bus_emit_signal(a, "/foo/bar/waldo", "waldo.com", "Piep", "sss", "I am a string", "/this/is/a/path", "and.this.a.domain.name");
         assert_se(r >= 0);
 
         r = sd_bus_process(b, &m);