X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Flibsystemd-bus%2Fbus-message.c;h=dbb33376192eb2a41b4537b3980316d17e9c125b;hb=5cbe749238f62546f70d81173a2778f3982adb03;hp=c1e1c468b81a46016d19359d0488148ae8294f11;hpb=c91cb83c4dbc9a95a0a2a38e7028e0a7f4af3b35;p=elogind.git

diff --git a/src/libsystemd-bus/bus-message.c b/src/libsystemd-bus/bus-message.c
index c1e1c468b..dbb333761 100644
--- a/src/libsystemd-bus/bus-message.c
+++ b/src/libsystemd-bus/bus-message.c
@@ -59,6 +59,8 @@ static void message_free_part(sd_bus_message *m, struct bus_body_part *part) {
         assert(part);
 
         if (part->memfd >= 0) {
+                /* If we can reuse the memfd, try that. For that it
+                 * can't be sealed yet. */
 
                 if (!part->sealed)
                         bus_kernel_push_memfd(m->bus, part->memfd, part->data, part->mapped);
@@ -69,7 +71,9 @@ static void message_free_part(sd_bus_message *m, struct bus_body_part *part) {
                         close_nointr_nofail(part->memfd);
                 }
 
-        } else if (part->free_this)
+        } else if (part->munmap_this)
+                munmap(part->data, part->mapped);
+        else if (part->free_this)
                 free(part->data);
 
         if (part != &m->body)
@@ -1119,8 +1123,13 @@ static void part_zero(struct bus_body_part *part, size_t sz) {
         assert(sz > 0);
         assert(sz < 8);
 
-        part->data = NULL;
+        /* All other fields can be left in their defaults */
+        assert(!part->data);
+        assert(part->memfd < 0);
+
         part->size = sz;
+        part->is_zero = true;
+        part->sealed = true;
 }
 
 static int part_make_space(
@@ -1151,8 +1160,8 @@ static int part_make_space(
                         return -errno;
                 }
 
-                if (sz > part->mapped) {
-                        size_t psz = PAGE_ALIGN(sz);
+                if (!part->data || sz > part->mapped) {
+                        size_t psz = PAGE_ALIGN(sz > 0 ? sz : 1);
 
                         if (part->mapped <= 0)
                                 n = mmap(NULL, psz, PROT_READ|PROT_WRITE, MAP_SHARED, part->memfd, 0);
@@ -1166,6 +1175,7 @@ static int part_make_space(
 
                         part->mapped = psz;
                         part->data = n;
+                        part->munmap_this = true;
                 }
         } else {
                 n = realloc(part->data, sz);
@@ -1185,8 +1195,22 @@ static int part_make_space(
         return 0;
 }
 
-static void *message_extend_body(sd_bus_message *m, size_t align, size_t sz) {
+static void message_extend_containers(sd_bus_message *m, size_t expand) {
         struct bus_container *c;
+
+        assert(m);
+
+        if (expand <= 0)
+                return;
+
+        /* Update counters */
+        for (c = m->containers; c < m->containers + m->n_containers; c++)
+                if (c->array_size)
+                        *c->array_size += expand;
+
+}
+
+static void *message_extend_body(sd_bus_message *m, size_t align, size_t sz) {
         struct bus_body_part *part = NULL;
         size_t start_body, end_body, padding, start_part, end_part, added;
         bool add_new_part;
@@ -1234,6 +1258,7 @@ static void *message_extend_body(sd_bus_message *m, size_t align, size_t sz) {
                 if (r < 0)
                         return NULL;
         } else {
+                struct bus_container *c;
                 void *op;
                 size_t os;
 
@@ -1260,12 +1285,8 @@ static void *message_extend_body(sd_bus_message *m, size_t align, size_t sz) {
                 m->error.message = (const char*) adjust_pointer(m->error.message, op, os, part->data);
         }
 
-        /* Update counters */
-        for (c = m->containers; c < m->containers + m->n_containers; c++)
-                if (c->array_size)
-                        *c->array_size += added;
-
         m->header->body_size = end_body;
+        message_extend_containers(m, added);
 
         return p;
 }
@@ -1275,7 +1296,6 @@ int message_append_basic(sd_bus_message *m, char type, const void *p, const void
         ssize_t align, sz;
         uint32_t k;
         void *a;
-        char *e = NULL;
         int fd = -1;
         uint32_t fdi = 0;
         int r;
@@ -1299,6 +1319,8 @@ int message_append_basic(sd_bus_message *m, char type, const void *p, const void
                 if (c->signature[c->index] != type)
                         return -ENXIO;
         } else {
+                char *e;
+
                 /* Maybe we can append to the signature? But only if this is the top-level container*/
                 if (c->enclosing != 0)
                         return -ENXIO;
@@ -1431,7 +1453,6 @@ int sd_bus_message_append_basic(sd_bus_message *m, char type, const void *p) {
 
 int sd_bus_message_append_string_space(sd_bus_message *m, size_t size, char **s) {
         struct bus_container *c;
-        char *e;
         void *a;
 
         if (!m)
@@ -1451,6 +1472,8 @@ int sd_bus_message_append_string_space(sd_bus_message *m, size_t size, char **s)
                 if (c->signature[c->index] != SD_BUS_TYPE_STRING)
                         return -ENXIO;
         } else {
+                char *e;
+
                 /* Maybe we can append to the signature? But only if this is the top-level container*/
                 if (c->enclosing != 0)
                         return -ENXIO;
@@ -1462,7 +1485,6 @@ int sd_bus_message_append_string_space(sd_bus_message *m, size_t size, char **s)
                 }
         }
 
-
         a = message_extend_body(m, 4, 4 + size + 1);
         if (!a)
                 return -ENOMEM;
@@ -1485,7 +1507,6 @@ static int bus_message_open_array(
                 uint32_t **array_size) {
 
         unsigned nindex;
-        char *e = NULL;
         void *a, *op;
         int alignment;
         size_t os;
@@ -1515,6 +1536,8 @@ static int bus_message_open_array(
 
                 nindex = c->index + 1 + strlen(contents);
         } else {
+                char *e;
+
                 if (c->enclosing != 0)
                         return -ENXIO;
 
@@ -1558,7 +1581,6 @@ static int bus_message_open_variant(
                 struct bus_container *c,
                 const char *contents) {
 
-        char *e = NULL;
         size_t l;
         void *a;
 
@@ -1578,6 +1600,8 @@ static int bus_message_open_variant(
                         return -ENXIO;
 
         } else {
+                char *e;
+
                 if (c->enclosing != 0)
                         return -ENXIO;
 
@@ -1608,7 +1632,6 @@ static int bus_message_open_struct(
                 const char *contents) {
 
         size_t nindex;
-        char *e = NULL;
 
         assert(m);
         assert(c);
@@ -1629,6 +1652,8 @@ static int bus_message_open_struct(
 
                 nindex = c->index + 1 + l + 1;
         } else {
+                char *e;
+
                 if (c->enclosing != 0)
                         return -ENXIO;
 
@@ -2099,6 +2124,212 @@ int sd_bus_message_append_array(sd_bus_message *m, char type, const void *ptr, s
         return 0;
 }
 
+int sd_bus_message_append_array_memfd(sd_bus_message *m, char type, sd_memfd *memfd) {
+        _cleanup_close_ int copy_fd = -1;
+        struct bus_body_part *part;
+        ssize_t align, sz;
+        uint64_t size;
+        void *a;
+        int r;
+
+        if (!m)
+                return -EINVAL;
+        if (!memfd)
+                return -EINVAL;
+        if (m->sealed)
+                return -EPERM;
+        if (!bus_type_is_trivial(type))
+                return -EINVAL;
+        if (m->poisoned)
+                return -ESTALE;
+
+        r = sd_memfd_set_sealed(memfd, true);
+        if (r < 0)
+                return r;
+
+        copy_fd = sd_memfd_dup_fd(memfd);
+        if (copy_fd < 0)
+                return copy_fd;
+
+        r = sd_memfd_get_size(memfd, &size);
+        if (r < 0)
+                return r;
+
+        align = bus_type_get_alignment(type);
+        sz = bus_type_get_size(type);
+
+        assert_se(align > 0);
+        assert_se(sz > 0);
+
+        if (size % sz != 0)
+                return -EINVAL;
+
+        if (size > (uint64_t) (uint32_t) -1)
+                return -EINVAL;
+
+        r = sd_bus_message_open_container(m, SD_BUS_TYPE_ARRAY, CHAR_TO_STR(type));
+        if (r < 0)
+                return r;
+
+        a = message_extend_body(m, align, 0);
+        if (!a)
+                return -ENOMEM;
+
+        part = message_append_part(m);
+        if (!part)
+                return -ENOMEM;
+
+        part->memfd = copy_fd;
+        part->sealed = true;
+        part->size = size;
+        copy_fd = -1;
+
+        message_extend_containers(m, size);
+        m->header->body_size += size;
+
+        return sd_bus_message_close_container(m);
+}
+
+int sd_bus_message_append_string_memfd(sd_bus_message *m, sd_memfd *memfd) {
+        _cleanup_close_ int copy_fd = -1;
+        struct bus_body_part *part;
+        struct bus_container *c;
+        uint64_t size;
+        void *a;
+        int r;
+
+        if (!m)
+                return -EINVAL;
+        if (!memfd)
+                return -EINVAL;
+        if (m->sealed)
+                return -EPERM;
+        if (m->poisoned)
+                return -ESTALE;
+
+        r = sd_memfd_set_sealed(memfd, true);
+        if (r < 0)
+                return r;
+
+        copy_fd = sd_memfd_dup_fd(memfd);
+        if (copy_fd < 0)
+                return copy_fd;
+
+        r = sd_memfd_get_size(memfd, &size);
+        if (r < 0)
+                return r;
+
+        /* We require this to be NUL terminated */
+        if (size == 0)
+                return -EINVAL;
+
+        if (size > (uint64_t) (uint32_t) -1)
+                return -EINVAL;
+
+        c = message_get_container(m);
+        if (c->signature && c->signature[c->index]) {
+                /* Container signature is already set */
+
+                if (c->signature[c->index] != SD_BUS_TYPE_STRING)
+                        return -ENXIO;
+        } else {
+                char *e;
+
+                /* Maybe we can append to the signature? But only if this is the top-level container*/
+                if (c->enclosing != 0)
+                        return -ENXIO;
+
+                e = strextend(&c->signature, CHAR_TO_STR(SD_BUS_TYPE_STRING), NULL);
+                if (!e) {
+                        m->poisoned = true;
+                        return -ENOMEM;
+                }
+        }
+
+        a = message_extend_body(m, 4, 4);
+        if (!a)
+                return -ENOMEM;
+
+        *(uint32_t*) a = size - 1;
+
+        part = message_append_part(m);
+        if (!part)
+                return -ENOMEM;
+
+        part->memfd = copy_fd;
+        part->sealed = true;
+        part->size = size;
+        copy_fd = -1;
+
+        message_extend_containers(m, size);
+        m->header->body_size += size;
+
+        if (c->enclosing != SD_BUS_TYPE_ARRAY)
+                c->index++;
+
+        return 0;
+}
+
+int bus_body_part_map(struct bus_body_part *part) {
+        void *p;
+        size_t psz;
+
+        assert_se(part);
+
+        if (part->data)
+                return 0;
+
+        if (part->size <= 0)
+                return 0;
+
+        /* For smaller zero parts (as used for padding) we don't need to map anything... */
+        if (part->memfd < 0 && part->is_zero && part->size < 8) {
+                static const uint8_t zeroes[7] = { };
+                part->data = (void*) zeroes;
+                return 0;
+        }
+
+        psz = PAGE_ALIGN(part->size);
+
+        if (part->memfd >= 0)
+                p = mmap(NULL, psz, PROT_READ, MAP_SHARED, part->memfd, 0);
+        else if (part->is_zero)
+                p = mmap(NULL, psz, PROT_READ, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+        else
+                return -EINVAL;
+
+        if (p == MAP_FAILED)
+                return -errno;
+
+        part->mapped = psz;
+        part->data = p;
+        part->munmap_this = true;
+
+        return 0;
+}
+
+void bus_body_part_unmap(struct bus_body_part *part) {
+
+        assert_se(part);
+
+        if (part->memfd < 0)
+                return;
+
+        if (!part->data)
+                return;
+
+        if (!part->munmap_this)
+                return;
+
+        assert_se(munmap(part->data, part->mapped) == 0);
+
+        part->data = NULL;
+        part->mapped = 0;
+        part->munmap_this = false;
+
+        return;
+}
+
 static int buffer_peek(const void *p, uint32_t sz, size_t *rindex, size_t align, size_t nbytes, void **r) {
         size_t k, start, end;
 
@@ -2139,6 +2370,8 @@ static bool message_end_of_array(sd_bus_message *m, size_t index) {
 static struct bus_body_part* find_part(sd_bus_message *m, size_t index, size_t sz, void **p) {
         struct bus_body_part *part;
         size_t begin;
+        int r;
+
         assert(m);
 
         if (m->cached_rindex_part && index >= m->cached_rindex_part_begin) {
@@ -2154,8 +2387,13 @@ static struct bus_body_part* find_part(sd_bus_message *m, size_t index, size_t s
                         return NULL;
 
                 if (index + sz <= begin + part->size) {
+
+                        r = bus_body_part_map(part);
+                        if (r < 0)
+                                return NULL;
+
                         if (p)
-                                *p = part->data ? (uint8_t*) part->data + index - begin : NULL;
+                                *p = (uint8_t*) part->data + index - begin;
 
                         m->cached_rindex_part = part;
                         m->cached_rindex_part_begin = begin;
@@ -2163,6 +2401,7 @@ static struct bus_body_part* find_part(sd_bus_message *m, size_t index, size_t s
                         return part;
                 }
 
+                begin += part->size;
                 part = part->next;
         }
 
@@ -3086,7 +3325,7 @@ int sd_bus_message_read_array(sd_bus_message *m, char type, const void **ptr, si
                 return align;
 
         r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, CHAR_TO_STR(type));
-        if (r < 0)
+        if (r <= 0)
                 return r;
 
         c = message_get_container(m);
@@ -3577,19 +3816,27 @@ int bus_message_seal(sd_bus_message *m, uint64_t serial) {
                         return r;
         }
 
-        /* Add padding at the end, since we know the body
-         * needs to start at an 8 byte alignment. */
-
+        /* Add padding at the end of the fields part, since we know
+         * the body needs to start at an 8 byte alignment. We made
+         * sure we allocated enough space for this, so all we need to
+         * do here is to zero it out. */
         l = BUS_MESSAGE_FIELDS_SIZE(m);
         a = ALIGN8(l) - l;
         if (a > 0)
                 memset((uint8_t*) BUS_MESSAGE_FIELDS(m) + l, 0, a);
 
-        MESSAGE_FOREACH_PART(part, i, m)
-                if (part->memfd >= 0 && !part->sealed) {
-                        ioctl(part->memfd, KDBUS_CMD_MEMFD_SEAL_SET, 1);
-                        part->sealed = true;
-                }
+        /* If this is something we can send as memfd, then let's seal
+        the memfd now. Note that we can send memfds as payload only
+        for directed messages, and not for broadcasts. */
+        if (m->destination) {
+                MESSAGE_FOREACH_PART(part, i, m)
+                        if (part->memfd >= 0 && !part->sealed && part->size > MEMFD_MIN_SIZE) {
+                                bus_body_part_unmap(part);
+
+                                if (ioctl(part->memfd, KDBUS_CMD_MEMFD_SEAL_SET, 1) >= 0)
+                                        part->sealed = true;
+                        }
+        }
 
         m->header->serial = serial;
         m->sealed = true;
@@ -3638,7 +3885,8 @@ int bus_message_dump(sd_bus_message *m) {
                "\treply_serial=%u\n"
                "\terror.name=%s\n"
                "\terror.message=%s\n"
-               "\tsealed=%s\n",
+               "\tsealed=%s\n"
+               "\tn_body_parts=%u\n",
                m,
                m->n_ref,
                m->header->endian,
@@ -3657,7 +3905,8 @@ int bus_message_dump(sd_bus_message *m) {
                m->reply_serial,
                strna(m->error.name),
                strna(m->error.message),
-               yes_no(m->sealed));
+               yes_no(m->sealed),
+               m->n_body_parts);
 
         if (m->pid != 0)
                 printf("\tpid=%lu\n", (unsigned long) m->pid);