bus: add API calls to escape string components of objects paths

TODO

@@ -72,8 +72,6 @@ Features:
 
 * sd-bus: support "const" properties as flag
 
-* sd-bus: add api call to escape bus path components
-
 * sd-event: when a handler returns an error, just turn off its event
   source, but do not return anything up to the event loop
   caller. Instead add parameter to sd_event_request_quit() to take

src/libsystemd-bus/libsystemd-bus.sym

@@ -187,6 +187,10 @@ global:
         sd_bus_error_is_set;
         sd_bus_error_has_name;
 
+        /* Escaping */
+        sd_bus_label_escape;
+        sd_bus_label_unescape;
+
         /* sd-memfd functions */
         sd_memfd_new;
         sd_memfd_make;

src/libsystemd-bus/sd-bus.c

@@ -2712,3 +2712,75 @@ _public_ int sd_bus_get_tid(sd_bus *b, pid_t *tid) {
 
         return -ENXIO;
 }
+
+_public_ char *sd_bus_label_escape(const char *s) {
+        char *r, *t;
+        const char *f;
+
+        assert_return(s, NULL);
+
+        /* Escapes all chars that D-Bus' object path cannot deal
+         * with. Can be reversed with bus_path_unescape(). We special
+         * case the empty string. */
+
+        if (*s == 0)
+                return strdup("_");
+
+        r = new(char, strlen(s)*3 + 1);
+        if (!r)
+                return NULL;
+
+        for (f = s, t = r; *f; f++) {
+
+                /* Escape everything that is not a-zA-Z0-9. We also
+                 * escape 0-9 if it's the first character */
+
+                if (!(*f >= 'A' && *f <= 'Z') &&
+                    !(*f >= 'a' && *f <= 'z') &&
+                    !(f > s && *f >= '0' && *f <= '9')) {
+                        *(t++) = '_';
+                        *(t++) = hexchar(*f >> 4);
+                        *(t++) = hexchar(*f);
+                } else
+                        *(t++) = *f;
+        }
+
+        *t = 0;
+
+        return r;
+}
+
+_public_ char *sd_bus_label_unescape(const char *f) {
+        char *r, *t;
+
+        assert_return(f, NULL);
+
+        /* Special case for the empty string */
+        if (streq(f, "_"))
+                return strdup("");
+
+        r = new(char, strlen(f) + 1);
+        if (!r)
+                return NULL;
+
+        for (t = r; *f; f++) {
+
+                if (*f == '_') {
+                        int a, b;
+
+                        if ((a = unhexchar(f[1])) < 0 ||
+                            (b = unhexchar(f[2])) < 0) {
+                                /* Invalid escape code, let's take it literal then */
+                                *(t++) = '_';
+                        } else {
+                                *(t++) = (char) ((a << 4) | b);
+                                f += 2;
+                        }
+                } else
+                        *(t++) = *f;
+        }
+
+        *t = 0;
+
+        return r;
+}

src/libsystemd-bus/test-bus-marshal.c

@@ -39,6 +39,29 @@
 #include "bus-util.h"
 #include "bus-dump.h"
 
+static void test_bus_label_escape_one(const char *a, const char *b) {
+        _cleanup_free_ char *t = NULL, *x = NULL, *y = NULL;
+
+        assert_se(t = sd_bus_label_escape(a));
+        assert_se(streq(t, b));
+
+        assert_se(x = sd_bus_label_unescape(t));
+        assert_se(streq(a, x));
+
+        assert_se(y = sd_bus_label_unescape(b));
+        assert_se(streq(a, y));
+}
+
+static void test_bus_label_escape(void) {
+        test_bus_label_escape_one("foo123bar", "foo123bar");
+        test_bus_label_escape_one("foo.bar", "foo_2ebar");
+        test_bus_label_escape_one("foo_2ebar", "foo_5f2ebar");
+        test_bus_label_escape_one("", "_");
+        test_bus_label_escape_one("_", "_5f");
+        test_bus_label_escape_one("1", "_31");
+        test_bus_label_escape_one(":1", "_3a1");
+}
+
 int main(int argc, char *argv[]) {
         _cleanup_bus_message_unref_ sd_bus_message *m = NULL, *copy = NULL;
         int r, boolean;
@@ -294,5 +317,7 @@ int main(int argc, char *argv[]) {
         assert_se(streq(c, "ccc"));
         assert_se(streq(d, "3"));
 
+        test_bus_label_escape();
+
         return 0;
 }

src/login/logind-seat-dbus.c

@@ -294,7 +294,7 @@ int seat_object_find(sd_bus *bus, const char *path, const char *interface, void
                 if (!p)
                         return 0;
 
-                e = bus_path_unescape(p);
+                e = sd_bus_label_unescape(p);
                 if (!e)
                         return -ENOMEM;
 
@@ -312,7 +312,7 @@ char *seat_bus_path(Seat *s) {
 
         assert(s);
 
-        t = bus_path_escape(s->id);
+        t = sd_bus_label_escape(s->id);
         if (!t)
                 return NULL;
 

src/login/logind-session-dbus.c

@@ -499,7 +499,7 @@ int session_object_find(sd_bus *bus, const char *path, const char *interface, vo
                 if (!p)
                         return 0;
 
-                e = bus_path_unescape(p);
+                e = sd_bus_label_unescape(p);
                 if (!e)
                         return -ENOMEM;
 
@@ -517,7 +517,7 @@ char *session_bus_path(Session *s) {
 
         assert(s);
 
-        t = bus_path_escape(s->id);
+        t = sd_bus_label_escape(s->id);
         if (!t)
                 return NULL;
 

src/machine/machine-dbus.c

@@ -176,7 +176,7 @@ int machine_object_find(sd_bus *bus, const char *path, const char *interface, vo
                 if (!p)
                         return 0;
 
-                e = bus_path_unescape(p);
+                e = sd_bus_label_unescape(p);
                 if (!e)
                         return -ENOMEM;
 
@@ -194,7 +194,7 @@ char *machine_bus_path(Machine *m) {
 
         assert(m);
 
-        e = bus_path_escape(m->name);
+        e = sd_bus_label_escape(m->name);
         if (!e)
                 return NULL;
 

src/shared/unit-name.c

@@ -23,6 +23,7 @@
 #include <string.h>
 #include <assert.h>
 
+#include "sd-bus.h"
 #include "path-util.h"
 #include "util.h"
 #include "unit-name.h"
@@ -459,7 +460,7 @@ char *unit_dbus_path_from_name(const char *name) {
 
         assert(name);
 
-        e = bus_path_escape(name);
+        e = sd_bus_label_escape(name);
         if (!e)
                 return NULL;
 
@@ -474,7 +475,7 @@ int unit_name_from_dbus_path(const char *path, char **name) {
         if (!e)
                 return -EINVAL;
 
-        n = bus_path_unescape(e);
+        n = sd_bus_label_unescape(e);
         if (!n)
                 return -ENOMEM;
 

src/shared/util.c

@@ -1356,78 +1356,6 @@ char *xescape(const char *s, const char *bad) {
         return r;
 }
 
-char *bus_path_escape(const char *s) {
-        char *r, *t;
-        const char *f;
-
-        assert(s);
-
-        /* Escapes all chars that D-Bus' object path cannot deal
-         * with. Can be reversed with bus_path_unescape(). We special
-         * case the empty string. */
-
-        if (*s == 0)
-                return strdup("_");
-
-        r = new(char, strlen(s)*3 + 1);
-        if (!r)
-                return NULL;
-
-        for (f = s, t = r; *f; f++) {
-
-                /* Escape everything that is not a-zA-Z0-9. We also
-                 * escape 0-9 if it's the first character */
-
-                if (!(*f >= 'A' && *f <= 'Z') &&
-                    !(*f >= 'a' && *f <= 'z') &&
-                    !(f > s && *f >= '0' && *f <= '9')) {
-                        *(t++) = '_';
-                        *(t++) = hexchar(*f >> 4);
-                        *(t++) = hexchar(*f);
-                } else
-                        *(t++) = *f;
-        }
-
-        *t = 0;
-
-        return r;
-}
-
-char *bus_path_unescape(const char *f) {
-        char *r, *t;
-
-        assert(f);
-
-        /* Special case for the empty string */
-        if (streq(f, "_"))
-                return strdup("");
-
-        r = new(char, strlen(f) + 1);
-        if (!r)
-                return NULL;
-
-        for (t = r; *f; f++) {
-
-                if (*f == '_') {
-                        int a, b;
-
-                        if ((a = unhexchar(f[1])) < 0 ||
-                            (b = unhexchar(f[2])) < 0) {
-                                /* Invalid escape code, let's take it literal then */
-                                *(t++) = '_';
-                        } else {
-                                *(t++) = (char) ((a << 4) | b);
-                                f += 2;
-                        }
-                } else
-                        *(t++) = *f;
-        }
-
-        *t = 0;
-
-        return r;
-}
-
 char *ascii_strlower(char *t) {
         char *p;
 

src/shared/util.h

@@ -237,9 +237,6 @@ char *cunescape_length_with_prefix(const char *s, size_t length, const char *pre
 
 char *xescape(const char *s, const char *bad);
 
-char *bus_path_escape(const char *s);
-char *bus_path_unescape(const char *s);
-
 char *ascii_strlower(char *path);
 
 bool dirent_is_file(const struct dirent *de) _pure_;

src/systemd/sd-bus.h

@@ -282,6 +282,9 @@ int sd_bus_error_has_name(const sd_bus_error *e, const char *name);
                 &(x).bytes[8],  &(x).bytes[9],  &(x).bytes[10], &(x).bytes[11], \
                 &(x).bytes[12], &(x).bytes[13], &(x).bytes[14], &(x).bytes[15]
 
+char *sd_bus_label_escape(const char *s);
+char *sd_bus_label_unescape(const char *f);
+
 _SD_END_DECLARATIONS;
 
 #endif

src/test/test-util.c

@@ -351,29 +351,6 @@ static void test_memdup_multiply(void) {
         free(dup);
 }
 
-static void test_bus_path_escape_one(const char *a, const char *b) {
-        _cleanup_free_ char *t = NULL, *x = NULL, *y = NULL;
-
-        assert_se(t = bus_path_escape(a));
-        assert_se(streq(t, b));
-
-        assert_se(x = bus_path_unescape(t));
-        assert_se(streq(a, x));
-
-        assert_se(y = bus_path_unescape(b));
-        assert_se(streq(a, y));
-}
-
-static void test_bus_path_escape(void) {
-        test_bus_path_escape_one("foo123bar", "foo123bar");
-        test_bus_path_escape_one("foo.bar", "foo_2ebar");
-        test_bus_path_escape_one("foo_2ebar", "foo_5f2ebar");
-        test_bus_path_escape_one("", "_");
-        test_bus_path_escape_one("_", "_5f");
-        test_bus_path_escape_one("1", "_31");
-        test_bus_path_escape_one(":1", "_3a1");
-}
-
 static void test_hostname_is_valid(void) {
         assert(hostname_is_valid("foobar"));
         assert(hostname_is_valid("foobar.com"));
@@ -616,7 +593,6 @@ int main(int argc, char *argv[]) {
         test_foreach_word_quoted();
         test_default_term_for_tty();
         test_memdup_multiply();
-        test_bus_path_escape();
         test_hostname_is_valid();
         test_u64log2();
         test_get_process_comm();