Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 353 insertions, 0 deletions

diff --git a/src/udev/udev-ctrl.c b/src/udev/udev-ctrl.c
new file mode 100644
index 0000000..2871634
--- /dev/null
+++ b/src/udev/udev-ctrl.c
@@ -0,0 +1,353 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <poll.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include "sd-event.h"
+
+#include "alloc-util.h"
+#include "errno-util.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "iovec-util.h"
+#include "socket-util.h"
+#include "strxcpyx.h"
+#include "udev-ctrl.h"
+
+/* wire protocol magic must match */
+#define UDEV_CTRL_MAGIC                                0xdead1dea
+
+typedef struct UdevCtrlMessageWire {
+        char version[16];
+        unsigned magic;
+        UdevCtrlMessageType type;
+        UdevCtrlMessageValue value;
+} UdevCtrlMessageWire;
+
+struct UdevCtrl {
+        unsigned n_ref;
+        int sock;
+        int sock_connect;
+        union sockaddr_union saddr;
+        socklen_t addrlen;
+        bool bound;
+        bool connected;
+        sd_event *event;
+        sd_event_source *event_source;
+        sd_event_source *event_source_connect;
+        udev_ctrl_handler_t callback;
+        void *userdata;
+};
+
+int udev_ctrl_new_from_fd(UdevCtrl **ret, int fd) {
+        _cleanup_close_ int sock = -EBADF;
+        UdevCtrl *uctrl;
+
+        assert(ret);
+
+        if (fd < 0) {
+                sock = socket(AF_UNIX, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
+                if (sock < 0)
+                        return log_error_errno(errno, "Failed to create socket: %m");
+        }
+
+        uctrl = new(UdevCtrl, 1);
+        if (!uctrl)
+                return -ENOMEM;
+
+        *uctrl = (UdevCtrl) {
+                .n_ref = 1,
+                .sock = fd >= 0 ? fd : TAKE_FD(sock),
+                .sock_connect = -EBADF,
+                .bound = fd >= 0,
+        };
+
+        uctrl->saddr.un = (struct sockaddr_un) {
+                .sun_family = AF_UNIX,
+                .sun_path = "/run/udev/control",
+        };
+
+        uctrl->addrlen = SOCKADDR_UN_LEN(uctrl->saddr.un);
+
+        *ret = TAKE_PTR(uctrl);
+        return 0;
+}
+
+int udev_ctrl_enable_receiving(UdevCtrl *uctrl) {
+        assert(uctrl);
+
+        if (uctrl->bound)
+                return 0;
+
+        (void) sockaddr_un_unlink(&uctrl->saddr.un);
+        if (bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen) < 0)
+                return log_error_errno(errno, "Failed to bind udev control socket: %m");
+
+        if (listen(uctrl->sock, 0) < 0)
+                return log_error_errno(errno, "Failed to listen udev control socket: %m");
+
+        uctrl->bound = true;
+        return 0;
+}
+
+static void udev_ctrl_disconnect(UdevCtrl *uctrl) {
+        if (!uctrl)
+                return;
+
+        uctrl->event_source_connect = sd_event_source_unref(uctrl->event_source_connect);
+        uctrl->sock_connect = safe_close(uctrl->sock_connect);
+}
+
+static UdevCtrl *udev_ctrl_free(UdevCtrl *uctrl) {
+        assert(uctrl);
+
+        udev_ctrl_disconnect(uctrl);
+
+        sd_event_source_unref(uctrl->event_source);
+        safe_close(uctrl->sock);
+
+        sd_event_unref(uctrl->event);
+        return mfree(uctrl);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(UdevCtrl, udev_ctrl, udev_ctrl_free);
+
+int udev_ctrl_attach_event(UdevCtrl *uctrl, sd_event *event) {
+        int r;
+
+        assert_return(uctrl, -EINVAL);
+        assert_return(!uctrl->event, -EBUSY);
+
+        if (event)
+                uctrl->event = sd_event_ref(event);
+        else {
+                r = sd_event_default(&uctrl->event);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+sd_event_source *udev_ctrl_get_event_source(UdevCtrl *uctrl) {
+        assert(uctrl);
+
+        return uctrl->event_source;
+}
+
+static void udev_ctrl_disconnect_and_listen_again(UdevCtrl *uctrl) {
+        udev_ctrl_disconnect(uctrl);
+        udev_ctrl_unref(uctrl);
+        (void) sd_event_source_set_enabled(uctrl->event_source, SD_EVENT_ON);
+        /* We don't return NULL here because uctrl is not freed */
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(UdevCtrl*, udev_ctrl_disconnect_and_listen_again, NULL);
+
+static int udev_ctrl_connection_event_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        _cleanup_(udev_ctrl_disconnect_and_listen_againp) UdevCtrl *uctrl = NULL;
+        UdevCtrlMessageWire msg_wire;
+        struct iovec iov = IOVEC_MAKE(&msg_wire, sizeof(UdevCtrlMessageWire));
+        CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control;
+        struct msghdr smsg = {
+                .msg_iov = &iov,
+                .msg_iovlen = 1,
+                .msg_control = &control,
+                .msg_controllen = sizeof(control),
+        };
+        struct ucred *cred;
+        ssize_t size;
+
+        assert(userdata);
+
+        /* When UDEV_CTRL_EXIT is received, manager unref udev_ctrl object.
+         * To avoid the object freed, let's increment the refcount. */
+        uctrl = udev_ctrl_ref(userdata);
+
+        size = next_datagram_size_fd(fd);
+        if (size < 0)
+                return log_error_errno(size, "Failed to get size of message: %m");
+        if (size == 0)
+                return 0; /* Client disconnects? */
+
+        size = recvmsg_safe(fd, &smsg, 0);
+        if (size == -EINTR)
+                return 0;
+        if (size < 0)
+                return log_error_errno(size, "Failed to receive ctrl message: %m");
+
+        cmsg_close_all(&smsg);
+
+        cred = CMSG_FIND_DATA(&smsg, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
+        if (!cred) {
+                log_error("No sender credentials received, ignoring message");
+                return 0;
+        }
+
+        if (cred->uid != 0) {
+                log_error("Invalid sender uid "UID_FMT", ignoring message", cred->uid);
+                return 0;
+        }
+
+        if (msg_wire.magic != UDEV_CTRL_MAGIC) {
+                log_error("Message magic 0x%08x doesn't match, ignoring message", msg_wire.magic);
+                return 0;
+        }
+
+        if (msg_wire.type == _UDEV_CTRL_END_MESSAGES)
+                return 0;
+
+        if (uctrl->callback)
+                (void) uctrl->callback(uctrl, msg_wire.type, &msg_wire.value, uctrl->userdata);
+
+        /* Do not disconnect and wait for next message. */
+        uctrl = udev_ctrl_unref(uctrl);
+        return 0;
+}
+
+static int udev_ctrl_event_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        UdevCtrl *uctrl = ASSERT_PTR(userdata);
+        _cleanup_close_ int sock = -EBADF;
+        struct ucred ucred;
+        int r;
+
+        sock = accept4(fd, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK);
+        if (sock < 0) {
+                if (ERRNO_IS_ACCEPT_AGAIN(errno))
+                        return 0;
+
+                return log_error_errno(errno, "Failed to accept ctrl connection: %m");
+        }
+
+        /* check peer credential of connection */
+        r = getpeercred(sock, &ucred);
+        if (r < 0) {
+                log_error_errno(r, "Failed to receive credentials of ctrl connection: %m");
+                return 0;
+        }
+
+        if (ucred.uid > 0) {
+                log_error("Invalid sender uid "UID_FMT", closing connection", ucred.uid);
+                return 0;
+        }
+
+        /* enable receiving of the sender credentials in the messages */
+        r = setsockopt_int(sock, SOL_SOCKET, SO_PASSCRED, true);
+        if (r < 0)
+                log_warning_errno(r, "Failed to set SO_PASSCRED, ignoring: %m");
+
+        r = sd_event_add_io(uctrl->event, &uctrl->event_source_connect, sock, EPOLLIN, udev_ctrl_connection_event_handler, uctrl);
+        if (r < 0) {
+                log_error_errno(r, "Failed to create event source for udev control connection: %m");
+                return 0;
+        }
+
+        (void) sd_event_source_set_description(uctrl->event_source_connect, "udev-ctrl-connection");
+
+        /* Do not accept multiple connection. */
+        (void) sd_event_source_set_enabled(uctrl->event_source, SD_EVENT_OFF);
+
+        uctrl->sock_connect = TAKE_FD(sock);
+        return 0;
+}
+
+int udev_ctrl_start(UdevCtrl *uctrl, udev_ctrl_handler_t callback, void *userdata) {
+        int r;
+
+        assert(uctrl);
+
+        if (!uctrl->event) {
+                r = udev_ctrl_attach_event(uctrl, NULL);
+                if (r < 0)
+                        return r;
+        }
+
+        r = udev_ctrl_enable_receiving(uctrl);
+        if (r < 0)
+                return r;
+
+        uctrl->callback = callback;
+        uctrl->userdata = userdata;
+
+        r = sd_event_add_io(uctrl->event, &uctrl->event_source, uctrl->sock, EPOLLIN, udev_ctrl_event_handler, uctrl);
+        if (r < 0)
+                return r;
+
+        (void) sd_event_source_set_description(uctrl->event_source, "udev-ctrl");
+
+        return 0;
+}
+
+int udev_ctrl_send(UdevCtrl *uctrl, UdevCtrlMessageType type, const void *data) {
+        UdevCtrlMessageWire ctrl_msg_wire = {
+                .version = "udev-" STRINGIFY(PROJECT_VERSION),
+                .magic = UDEV_CTRL_MAGIC,
+                .type = type,
+        };
+
+        if (type == UDEV_CTRL_SET_ENV) {
+                assert(data);
+                strscpy(ctrl_msg_wire.value.buf, sizeof(ctrl_msg_wire.value.buf), data);
+        } else if (IN_SET(type, UDEV_CTRL_SET_LOG_LEVEL, UDEV_CTRL_SET_CHILDREN_MAX))
+                ctrl_msg_wire.value.intval = PTR_TO_INT(data);
+
+        if (!uctrl->connected) {
+                if (connect(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen) < 0)
+                        return -errno;
+                uctrl->connected = true;
+        }
+
+        if (send(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int udev_ctrl_wait(UdevCtrl *uctrl, usec_t timeout) {
+        _cleanup_(sd_event_source_disable_unrefp) sd_event_source *source_io = NULL, *source_timeout = NULL;
+        int r;
+
+        assert(uctrl);
+
+        if (uctrl->sock < 0)
+                return 0;
+        if (!uctrl->connected)
+                return 0;
+
+        r = udev_ctrl_send(uctrl, _UDEV_CTRL_END_MESSAGES, NULL);
+        if (r < 0)
+                return r;
+
+        if (timeout == 0)
+                return 0;
+
+        if (!uctrl->event) {
+                r = udev_ctrl_attach_event(uctrl, NULL);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sd_event_add_io(uctrl->event, &source_io, uctrl->sock, EPOLLIN, NULL, INT_TO_PTR(0));
+        if (r < 0)
+                return r;
+
+        (void) sd_event_source_set_description(source_io, "udev-ctrl-wait-io");
+
+        if (timeout != USEC_INFINITY) {
+                r = sd_event_add_time_relative(
+                                uctrl->event, &source_timeout, CLOCK_BOOTTIME,
+                                timeout,
+                                0, NULL, INT_TO_PTR(-ETIMEDOUT));
+                if (r < 0)
+                        return r;
+
+                (void) sd_event_source_set_description(source_timeout, "udev-ctrl-wait-timeout");
+        }
+
+        return sd_event_loop(uctrl->event);
+}