payload: use fd_handle instead of raw file descriptors

[lttng-tools.git] / src / common / unix.c

diff --git a/src/common/unix.c b/src/common/unix.c
index f50611b5b0eac52ad8ac92502826038eec10afeb..50200242529992ce4b8244d4c4d897a28d35583d 100644 (file)
--- a/src/common/unix.c
+++ b/src/common/unix.c
@@ -19,6 +19,7 @@
 
 #include <common/common.h>
 #include <common/sessiond-comm/sessiond-comm.h>
 
 #include <common/common.h>
 #include <common/sessiond-comm/sessiond-comm.h>

+#include <common/fd-handle.h>

 
 #include "unix.h"
 
 
 #include "unix.h"
 


@@ -435,6 +436,73 @@ ssize_t lttcomm_send_fds_unix_sock(int sock, const int *fds, size_t nb_fd)
        return ret;
 }
 
        return ret;
 }
 

+/*
+ * Send the fd(s) of a payload view over a unix socket.
+ *
+ * Returns the size of data sent, or negative error value.
+ */
+static
+ssize_t _lttcomm_send_payload_view_fds_unix_sock(int sock,
+               struct lttng_payload_view *view,
+               bool blocking)
+{
+       int i;
+       ssize_t ret;
+       struct lttng_dynamic_array raw_fds;
+       const int fd_count = lttng_payload_view_get_fd_handle_count(view);
+
+       lttng_dynamic_array_init(&raw_fds, sizeof(int), NULL);
+
+       /*
+        * Prepare a contiguous array of file descriptors to send them.
+        *
+        * Note that the reference to each fd is released during the iteration;
+        * we're just getting the numerical value of the fds to conform to the
+        * syscall's interface. We rely on the fact that "view" must remain
+        * valid for the duration of the call and that the underlying payload
+        * owns a reference to the fd_handles.
+        */
+       for (i = 0; i < fd_count; i++) {
+               struct fd_handle *handle =
+                               lttng_payload_view_pop_fd_handle(view);
+               const int raw_fd = fd_handle_get_fd(handle);
+               const int add_ret = lttng_dynamic_array_add_element(
+                               &raw_fds, &raw_fd);
+
+               fd_handle_put(handle);
+               if (add_ret) {
+                       ret = -LTTNG_ERR_NOMEM;
+                       goto end;
+               }
+       }
+
+       if (blocking) {
+               ret = lttcomm_send_fds_unix_sock(sock,
+                               (const int *) raw_fds.buffer.data, fd_count);
+       } else {
+               ret = lttcomm_send_fds_unix_sock_non_block(sock,
+                               (const int *) raw_fds.buffer.data, fd_count);
+       }
+
+end:
+       lttng_dynamic_array_reset(&raw_fds);
+       return ret;
+}
+
+LTTNG_HIDDEN
+ssize_t lttcomm_send_payload_view_fds_unix_sock(int sock,
+               struct lttng_payload_view *view)
+{
+       return _lttcomm_send_payload_view_fds_unix_sock(sock, view, true);
+}
+
+LTTNG_HIDDEN
+ssize_t lttcomm_send_payload_view_fds_unix_sock_non_block(int sock,
+               struct lttng_payload_view *view)
+{
+       return _lttcomm_send_payload_view_fds_unix_sock(sock, view, false);
+}
+

 /*
  * Send a message accompanied by fd(s) over a unix socket.
  * Only use for non blocking socket.
 /*
  * Send a message accompanied by fd(s) over a unix socket.
  * Only use for non blocking socket.


@@ -629,6 +697,107 @@ end:
        return ret;
 }
 
        return ret;
 }
 

+static
+void close_raw_fd(void *ptr)
+{
+       const int raw_fd = *((const int *) ptr);
+
+       if (raw_fd >= 0) {
+               const int ret = close(raw_fd);
+
+               if (ret) {
+                       PERROR("Failed to close file descriptor %d", raw_fd);
+               }
+       }
+}
+
+static
+enum lttng_error_code add_fds_to_payload(struct lttng_dynamic_array *raw_fds,
+               struct lttng_payload *payload)
+{
+       int i;
+       enum lttng_error_code ret_code = LTTNG_OK;
+       const int fd_count = lttng_dynamic_array_get_count(raw_fds);
+
+       for (i = 0; i < fd_count; i++) {
+               int ret;
+               struct fd_handle *handle;
+               int *raw_fd = (int *) lttng_dynamic_array_get_element(
+                       raw_fds, i);
+
+               handle = fd_handle_create(*raw_fd);
+               if (!handle) {
+                       ret_code = LTTNG_ERR_NOMEM;
+                       goto end;
+               }
+
+               /* FD ownership transferred to the handle. */
+               *raw_fd = -1;
+
+               ret = lttng_payload_push_fd_handle(payload, handle);
+               fd_handle_put(handle);
+               if (ret) {
+                       ret_code = LTTNG_ERR_NOMEM;
+                       goto end;
+               }
+       }
+
+end:
+       return ret_code;
+}
+
+static
+ssize_t _lttcomm_recv_payload_fds_unix_sock(int sock, size_t nb_fd,
+               struct lttng_payload *payload, bool blocking)
+{
+       enum lttng_error_code add_ret;
+       ssize_t ret;
+       struct lttng_dynamic_array raw_fds;
+
+       lttng_dynamic_array_init(&raw_fds, sizeof(int), close_raw_fd);
+       ret = lttng_dynamic_array_set_count(&raw_fds, nb_fd);
+       if (ret) {
+               ret = -LTTNG_ERR_NOMEM;
+               goto end;
+       }
+
+       if (blocking) {
+               ret = lttcomm_recv_fds_unix_sock(
+                               sock, (int *) raw_fds.buffer.data, nb_fd);
+       } else {
+               ret = lttcomm_recv_fds_unix_sock_non_block(
+                               sock, (int *) raw_fds.buffer.data, nb_fd);
+       }
+
+       if (ret < 0) {
+               goto end;
+       }
+
+       add_ret = add_fds_to_payload(&raw_fds, payload);
+       if (add_ret != LTTNG_OK) {
+               ret = - (int) add_ret;
+               goto end;
+       }
+
+end:
+       lttng_dynamic_array_reset(&raw_fds);
+       return ret;
+}
+
+LTTNG_HIDDEN
+ssize_t lttcomm_recv_payload_fds_unix_sock(int sock, size_t nb_fd,
+                          struct lttng_payload *payload)
+{
+       return _lttcomm_recv_payload_fds_unix_sock(sock, nb_fd, payload, true);
+}
+
+LTTNG_HIDDEN
+ssize_t lttcomm_recv_payload_fds_unix_sock_non_block(int sock, size_t nb_fd,
+                          struct lttng_payload *payload)
+{
+       return _lttcomm_recv_payload_fds_unix_sock(sock, nb_fd, payload, false);
+}
+

 /*
  * Recv a message accompanied by fd(s) from a non-blocking unix socket.
  * Only use with non-blocking sockets.
 /*
  * Recv a message accompanied by fd(s) from a non-blocking unix socket.
  * Only use with non-blocking sockets.