daniel has submitted this change. ( 
https://gerrit.osmocom.org/c/libosmocore/+/30934 )

Change subject: Add osmo_io with initial poll backend
......................................................................

Add osmo_io with initial poll backend

* make backend configurable for later
* segmentation callback for chunked streams
* logging target for osmo_io
* support partial writes

Change-Id: I50d73cf550d6ce8154bf827bf47408131cf5b0a0
Related: SYS#5094, OS#5751
---
M TODO-RELEASE
M include/osmocom/core/Makefile.am
M include/osmocom/core/logging.h
A include/osmocom/core/osmo_io.h
M src/core/Makefile.am
M src/core/libosmocore.map
M src/core/logging.c
A src/core/osmo_io.c
A src/core/osmo_io_internal.h
A src/core/osmo_io_poll.c
M tests/logging/logging_vty_test.vty
11 files changed, 1,064 insertions(+), 3 deletions(-)

Approvals:
  laforge: Looks good to me, approved
  fixeria: Looks good to me, but someone else must approve
  dexter: Looks good to me, but someone else must approve
  Jenkins Builder: Verified




diff --git a/TODO-RELEASE b/TODO-RELEASE
index bade6f5..7270257 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -10,3 +10,4 @@
 libosmogsm  new header osmocom/gsm/protocol/gsm_44_060.h
 libosmocore ADD     new defines in osmocom/gsm/protocol/gsm_04_08.h (old ones 
marked deprecated)
 libosmovty     drop API                drop struct vty_parent_node from public 
API, it should never have been public
+libosmocore ADD     new API osmo_io_*()
diff --git a/include/osmocom/core/Makefile.am b/include/osmocom/core/Makefile.am
index e1cd92a..1d394cd 100644
--- a/include/osmocom/core/Makefile.am
+++ b/include/osmocom/core/Makefile.am
@@ -37,6 +37,7 @@
        msgb.h \
        netdev.h \
        netns.h \
+       osmo_io.h \
        panic.h \
        prbs.h \
        prim.h \
diff --git a/include/osmocom/core/logging.h b/include/osmocom/core/logging.h
index 755564d..e8433a1 100644
--- a/include/osmocom/core/logging.h
+++ b/include/osmocom/core/logging.h
@@ -154,7 +154,8 @@
 #define DLCSN1         -26     /*!< CSN.1 (Concrete Syntax Notation 1) codec */
 #define DLM2PA         -27     /*!< Osmocom M2PA (libosmo-sigtran) */
 #define DLM2UA         -28     /*!< Reserved for future Osmocom M2UA 
(libosmo-sigtran) */
-#define OSMO_NUM_DLIB  28      /*!< Number of logging sub-systems in libraries 
*/
+#define DLIO           -29     /*!< Osmocom IO sub-system */
+#define OSMO_NUM_DLIB  29      /*!< Number of logging sub-systems in libraries 
*/

 /* Colors that can be used in log_info_cat.color */
 #define OSMO_LOGCOLOR_NORMAL NULL
diff --git a/include/osmocom/core/osmo_io.h b/include/osmocom/core/osmo_io.h
new file mode 100644
index 0000000..ffc8cfa
--- /dev/null
+++ b/include/osmocom/core/osmo_io.h
@@ -0,0 +1,90 @@
+/*! \file osmo_io.h
+ *  io(_uring) abstraction osmo fd compatibility
+ */
+
+#pragma once
+
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/utils.h>
+
+
+#define LOGPIO(iofd, level, fmt, args...) \
+       LOGP(DLIO, level, "iofd(%s)" fmt, iofd->name, ## args)
+
+struct osmo_io_fd;
+
+enum osmo_io_fd_mode {
+       /*! use read() / write() calls */
+       OSMO_IO_FD_MODE_READ_WRITE,
+       /*! use recvfrom() / sendto() calls */
+       OSMO_IO_FD_MODE_RECVFROM_SENDTO,
+       /*! emulate sctp_recvmsg() and sctp_sendmsg() */
+       OSMO_IO_FD_MODE_SCTP_RECVMSG_SENDMSG,
+};
+
+enum osmo_io_backend {
+       OSMO_IO_BACKEND_POLL,
+};
+
+extern const struct value_string osmo_io_backend_names[];
+static inline const char *osmo_io_backend_name(enum osmo_io_backend val)
+{ return get_value_string(osmo_io_backend_names, val); }
+
+struct osmo_io_ops {
+       union {
+               /* mode OSMO_IO_FD_MODE_READ_WRITE: */
+               struct {
+                       /*! call-back function when something was read from fd 
*/
+                       void (*read_cb)(struct osmo_io_fd *iofd, int res, 
struct msgb *msg);
+                       /*! call-back function when write has completed on fd */
+                       void (*write_cb)(struct osmo_io_fd *iofd, int res,
+                                        const struct msgb *msg);
+                       /*! call-back function to segment the data returned by 
read_cb */
+                       int (*segmentation_cb)(struct msgb *msg, int data_len);
+               };
+
+               /* mode OSMO_IO_FD_MODE_RECVFROM_SENDTO: */
+               struct {
+                       /*! call-back function emulating sendto */
+                       void (*sendto_cb)(struct osmo_io_fd *iofd, int res,
+                                         const struct msgb *msg,
+                                         const struct osmo_sockaddr *daddr);
+                       /*! call-back function emulating recvfrom */
+                       void (*recvfrom_cb)(struct osmo_io_fd *iofd, int res,
+                                           struct msgb *msg,
+                                           const struct osmo_sockaddr *saddr);
+               };
+       };
+};
+
+void osmo_io_init(void);
+
+struct osmo_io_fd *osmo_iofd_setup(const void *ctx, int fd, const char *name,
+                 enum osmo_io_fd_mode mode, const struct osmo_io_ops *ioops, 
void *data);
+int osmo_iofd_register(struct osmo_io_fd *iofd, int fd);
+int osmo_iofd_unregister(struct osmo_io_fd *iofd);
+unsigned int osmo_iofd_txqueue_len(struct osmo_io_fd *iofd);
+void osmo_iofd_txqueue_clear(struct osmo_io_fd *iofd);
+int osmo_iofd_close(struct osmo_io_fd *iofd);
+void osmo_iofd_free(struct osmo_io_fd *iofd);
+void osmo_iofd_read_enable(struct osmo_io_fd *iofd);
+void osmo_iofd_read_disable(struct osmo_io_fd *iofd);
+void osmo_iofd_write_enable(struct osmo_io_fd *iofd);
+void osmo_iofd_write_disable(struct osmo_io_fd *iofd);
+
+int osmo_iofd_write_msgb(struct osmo_io_fd *iofd, struct msgb *msg);
+int osmo_iofd_sendto_msgb(struct osmo_io_fd *iofd, struct msgb *msg, int 
sendto_flags,
+                         const struct osmo_sockaddr *dest);
+
+void osmo_iofd_set_alloc_info(struct osmo_io_fd *iofd, unsigned int size, 
unsigned int headroom);
+void *osmo_iofd_get_data(const struct osmo_io_fd *iofd);
+void osmo_iofd_set_data(struct osmo_io_fd *iofd, void *data);
+
+unsigned int osmo_iofd_get_priv_nr(const struct osmo_io_fd *iofd);
+void osmo_iofd_set_priv_nr(struct osmo_io_fd *iofd, unsigned int priv_nr);
+
+int osmo_iofd_get_fd(const struct osmo_io_fd *iofd);
+const char *osmo_iofd_get_name(const struct osmo_io_fd *iofd);
diff --git a/src/core/Makefile.am b/src/core/Makefile.am
index 50c39d1..80ee458 100644
--- a/src/core/Makefile.am
+++ b/src/core/Makefile.am
@@ -50,6 +50,8 @@
        msgb.c \
        netdev.c \
        netns.c \
+       osmo_io.c \
+       osmo_io_poll.c \
        panic.c \
        prbs.c \
        prim.c \
@@ -107,6 +109,7 @@
        conv_acc_sse_impl.h \
        conv_acc_neon_impl.h \
        crcXXgen.c.tpl \
+       osmo_io_internal.h \
        stat_item_internal.h \
        libosmocore.map \
        $(NULL)
diff --git a/src/core/libosmocore.map b/src/core/libosmocore.map
index 095a4c0..7bca331 100644
--- a/src/core/libosmocore.map
+++ b/src/core/libosmocore.map
@@ -252,6 +252,30 @@
 osmo_init_logging2;
 osmo_int_to_float_str_buf;
 osmo_int_to_float_str_c;
+osmo_io_backend_names;
+osmo_iofd_close;
+osmo_iofd_free;
+osmo_iofd_get_data;
+osmo_iofd_get_fd;
+osmo_iofd_get_name;
+osmo_iofd_get_priv_nr;
+osmo_iofd_init;
+osmo_iofd_ops;
+osmo_iofd_read_disable;
+osmo_iofd_read_enable;
+osmo_iofd_register;
+osmo_iofd_sendto_msgb;
+osmo_iofd_set_alloc_info;
+osmo_iofd_set_data;
+osmo_iofd_set_priv_nr;
+osmo_iofd_setup;
+osmo_iofd_txqueue_clear;
+osmo_iofd_txqueue_len;
+osmo_iofd_unregister;
+osmo_iofd_uring_init;
+osmo_iofd_write_disable;
+osmo_iofd_write_enable;
+osmo_iofd_write_msgb;
 osmo_ip_str_type;
 osmo_isdnhdlc_decode;
 osmo_isdnhdlc_encode;
diff --git a/src/core/logging.c b/src/core/logging.c
index 3095f0d..c6774f5 100644
--- a/src/core/logging.c
+++ b/src/core/logging.c
@@ -313,6 +313,12 @@
                .enabled = 1, .loglevel = LOGL_NOTICE,
                .color = "\033[38;5;11m",
        },
+       [INT2IDX(DLIO)] = {
+               .name = "DLIO",
+               .description = "libosmocore IO Subsystem",
+               .enabled = 1, .loglevel = LOGL_NOTICE,
+               .color = "\033[38;5;67m",
+       },
 };

 void assert_loginfo(const char *src)
diff --git a/src/core/osmo_io.c b/src/core/osmo_io.c
new file mode 100644
index 0000000..cfb6d68
--- /dev/null
+++ b/src/core/osmo_io.c
@@ -0,0 +1,602 @@
+/*! \file osmo_io.c
+ * New osmocom async I/O API.
+ *
+ * (C) 2022 by Harald Welte <lafo...@osmocom.org>
+ * (C) 2022-2023 by sysmocom - s.f.m.c. GmbH <i...@sysmocom.de>
+ * Author: Daniel Willmann <dwillm...@sysmocom.de>
+ *
+ * All Rights Reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ */
+
+#include "../config.h"
+#if defined(__linux__)
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <talloc.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdbool.h>
+#include <errno.h>
+
+#include <osmocom/core/osmo_io.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/utils.h>
+
+#include "osmo_io_internal.h"
+
+/*! This environment variable can be set to manually set the backend used in 
osmo_io */
+#define OSMO_IO_BACKEND_ENV "LIBOSMO_IO_BACKEND"
+
+const struct value_string osmo_io_backend_names[] = {
+       { OSMO_IO_BACKEND_POLL, "poll" },
+       { 0, NULL }
+};
+
+static enum osmo_io_backend g_io_backend;
+
+/* Used by some tests, can't be static */
+struct iofd_backend_ops osmo_iofd_ops;
+
+/*! initialize osmo_io for the current thread */
+void osmo_iofd_init(void)
+{
+       switch (g_io_backend) {
+       case OSMO_IO_BACKEND_POLL:
+               break;
+       default:
+               OSMO_ASSERT(0);
+               break;
+       }
+}
+
+/* ensure main thread always has pre-initialized osmo_io
+ * priority 103: run after on_dso_load_select */
+static __attribute__((constructor(103))) void on_dso_load_osmo_io(void)
+{
+       char *backend = getenv(OSMO_IO_BACKEND_ENV);
+       if (backend == NULL)
+               backend = OSMO_IO_BACKEND_DEFAULT;
+
+       if (!strcmp("POLL", backend)) {
+               g_io_backend = OSMO_IO_BACKEND_POLL;
+               osmo_iofd_ops = iofd_poll_ops;
+       } else {
+               fprintf(stderr, "Invalid osmo_io backend requested: 
\"%s\"\nCheck the environment variable %s\n", backend, OSMO_IO_BACKEND_ENV);
+               exit(1);
+       }
+
+       osmo_iofd_init();
+}
+
+/*! Allocate the msghdr
+ *  \param[in] iofd the osmo_io file structure
+ *  \param[in] action the action this msg(hdr) is for (read, write, ..)
+ *  \param[in] msg the msg buffer to use. Will allocate a new one if NULL
+ *  \returns the newly allocated msghdr or NULL in case of error */
+struct iofd_msghdr *iofd_msghdr_alloc(struct osmo_io_fd *iofd, enum 
iofd_msg_action action, struct msgb *msg)
+{
+       struct iofd_msghdr *hdr = talloc_zero(iofd, struct iofd_msghdr);
+       if (!hdr)
+               return NULL;
+       if (!msg) {
+               msg = iofd_msgb_alloc(iofd);
+               if (!msg) {
+                       talloc_free(hdr);
+                       return NULL;
+               }
+       }
+
+       hdr->action = action;
+       hdr->iofd = iofd;
+       hdr->msg = msg;
+
+       return hdr;
+}
+
+/*! Free the msghdr
+ *  \param[in] msghdr the msghdr to free
+ */
+void iofd_msghdr_free(struct iofd_msghdr *msghdr)
+{
+       /* msghdr->msg is never owned by msghdr, it will either be freed in the 
send path or
+        * or passed on to the read callback which takes ownership. */
+       talloc_free(msghdr);
+}
+
+/*! convenience wrapper to call msgb_alloc with parameters from osmo_io_fd */
+struct msgb *iofd_msgb_alloc(struct osmo_io_fd *iofd)
+{
+       uint16_t headroom = iofd->msgb_alloc.headroom;
+
+       OSMO_ASSERT(iofd->msgb_alloc.size < 0xffff - headroom);
+       return msgb_alloc_headroom_c(iofd->msgb_alloc.ctx,
+                                    iofd->msgb_alloc.size + headroom, 
headroom, iofd->name);
+}
+
+/*! return the pending msgb in iofd or NULL if there is none*/
+struct msgb *iofd_msgb_pending(struct osmo_io_fd *iofd)
+{
+       struct msgb *msg = NULL;
+
+       msg = iofd->pending;
+       iofd->pending = NULL;
+
+       return msg;
+}
+
+/*! Return the pending msgb or allocate and return a new one */
+struct msgb *iofd_msgb_pending_or_alloc(struct osmo_io_fd *iofd)
+{
+       struct msgb *msg = NULL;
+
+       msg = iofd_msgb_pending(iofd);
+       if (!msg)
+               msg = iofd_msgb_alloc(iofd);
+
+       return msg;
+}
+
+/*! Enqueue a message to be sent
+ *
+ *  Enqueues the message at the back of the queue provided there is enough 
space.
+ *  \param[in] iofd the file descriptor
+ *  \param[in] msghdr the message to enqueue
+ *  \returns 0 if the message was enqueued succcessfully,
+ *    -ENOSPC if the queue already contains the maximum number of messages
+ */
+int iofd_txqueue_enqueue(struct osmo_io_fd *iofd, struct iofd_msghdr *msghdr)
+{
+       if (iofd->tx_queue.current_length >= iofd->tx_queue.max_length)
+               return -ENOSPC;
+
+       llist_add_tail(&msghdr->list, &iofd->tx_queue.msg_queue);
+       iofd->tx_queue.current_length++;
+
+       if (iofd->write_enabled && iofd->tx_queue.current_length == 1)
+               osmo_iofd_ops.write_enable(iofd);
+
+       return 0;
+}
+
+/*! Enqueue a message at the front
+ *
+ *  Used to enqueue a msgb from a partial send again. This function will always
+ *  enqueue the message, even if the maximum number of messages is reached.
+ *  \param[in] iofd the file descriptor
+ *  \param[in] msghdr the message to enqueue
+ */
+void iofd_txqueue_enqueue_front(struct osmo_io_fd *iofd, struct iofd_msghdr 
*msghdr)
+{
+       llist_add(&msghdr->list, &iofd->tx_queue.msg_queue);
+       iofd->tx_queue.current_length++;
+}
+
+/*! Dequeue a message from the front
+ *
+ *  \param[in] iofd the file descriptor
+ *  \returns the msghdr from the front of the queue or NULL if the queue is 
empty
+ */
+struct iofd_msghdr *iofd_txqueue_dequeue(struct osmo_io_fd *iofd)
+{
+       struct llist_head *lh;
+
+       if (iofd->tx_queue.current_length == 0)
+               return NULL;
+
+       lh = iofd->tx_queue.msg_queue.next;
+
+       OSMO_ASSERT(lh);
+       iofd->tx_queue.current_length--;
+       llist_del(lh);
+
+       if (iofd->tx_queue.current_length == 0)
+               osmo_iofd_ops.write_disable(iofd);
+
+       return llist_entry(lh, struct iofd_msghdr, list);
+}
+
+/*! Handle segmentation of the msg. If this function returns *_HANDLE_ONE or 
MORE then the data in msg will contain
+ *  one complete message.
+ *  If there are bytes left over, *pending_out will point to a msgb with the 
remaining data.
+*/
+static enum iofd_seg_act iofd_handle_segmentation(struct osmo_io_fd *iofd, 
struct msgb *msg, struct msgb **pending_out)
+{
+       int pending_len, msg_len;
+       struct msgb *msg_pending;
+
+       msg_len = msgb_length(msg);
+
+       if (!iofd->io_ops.segmentation_cb) {
+               *pending_out = NULL;
+               return IOFD_SEG_ACT_HANDLE_ONE;
+       }
+
+       int len = iofd->io_ops.segmentation_cb(msg, msg_len);
+
+       pending_len = msg_len - len;
+       /* No segmentation needed, return */
+       if (pending_len == 0) {
+               *pending_out = NULL;
+               return IOFD_SEG_ACT_HANDLE_ONE;
+       } else if (pending_len < 0) {
+               *pending_out = msg;
+               return IOFD_SEG_ACT_DEFER;
+       }
+
+       /* Copy the pending data over */
+       msg_pending = iofd_msgb_alloc(iofd);
+       memcpy(msgb_data(msg_pending), msgb_data(msg) + len, pending_len);
+       msgb_put(msg_pending, pending_len);
+       *pending_out = msg_pending;
+
+       /* Trim the original msgb to size */
+       msgb_trim(msg, len);
+       return IOFD_SEG_ACT_HANDLE_MORE;
+}
+
+/*! Restore message boundaries on read() and pass individual messages to the 
read callback
+ */
+void iofd_handle_segmented_read(struct osmo_io_fd *iofd, struct msgb *msg, int 
rc)
+{
+       int res;
+       struct msgb *pending = NULL;
+
+       if (rc <= 0) {
+               iofd->io_ops.read_cb(iofd, rc, msg);
+               return;
+       }
+
+       do {
+               res = iofd_handle_segmentation(iofd, msg, &pending);
+               if (res != IOFD_SEG_ACT_DEFER || rc < 0)
+                       iofd->io_ops.read_cb(iofd, rc, msg);
+               if (res == IOFD_SEG_ACT_HANDLE_MORE)
+                       msg = pending;
+       } while (res == IOFD_SEG_ACT_HANDLE_MORE);
+
+       OSMO_ASSERT(iofd->pending == NULL);
+       iofd->pending = pending;
+}
+
+/* Public functions */
+
+/*! Send a message through a connected socket
+ *
+ *  Appends the message to the internal transmit queue.
+ *  If the function returns success (0) it will take ownership of the msgb and
+ *  internally call msgb_free() after the write request completes.
+ *  In case of an error the msgb needs to be freed by the caller.
+ *  \param[in] iofd file descriptor to write to
+ *  \param[in] msg message buffer to write
+ *  \returns 0 in case of success; a negative value in case of error
+ */
+int osmo_iofd_write_msgb(struct osmo_io_fd *iofd, struct msgb *msg)
+{
+       int rc;
+       struct iofd_msghdr *msghdr = iofd_msghdr_alloc(iofd, IOFD_ACT_WRITE, 
msg);
+       if (!msghdr)
+               return -ENOMEM;
+
+       msghdr->flags = 0;
+       msghdr->iov[0].iov_base = msgb_data(msghdr->msg);
+       msghdr->iov[0].iov_len = msgb_length(msghdr->msg);
+       msghdr->hdr.msg_iov = &msghdr->iov[0];
+       msghdr->hdr.msg_iovlen = 1;
+
+       rc = iofd_txqueue_enqueue(iofd, msghdr);
+       if (rc < 0) {
+               iofd_msghdr_free(msghdr);
+               LOGPIO(iofd, LOGL_ERROR, "enqueueing message failed (%d). 
Rejecting msgb\n", rc);
+               return rc;
+       }
+
+       return 0;
+}
+
+/*! Send a message through an unconnected socket
+ *
+ *  Appends the message to the internal transmit queue.
+ *  If the function returns success (0), it will take ownership of the msgb and
+ *  internally call msgb_free() after the write request completes.
+ *  In case of an error the msgb needs to be freed by the caller.
+ *  \param[in] iofd file descriptor to write to
+ *  \param[in] msg message buffer to send
+ *  \param[in] sendto_flags Flags to pass to the send call
+ *  \param[in] dest destination address to send the message to
+ *  \returns 0 in case of success; a negative value in case of error
+ */
+int osmo_iofd_sendto_msgb(struct osmo_io_fd *iofd, struct msgb *msg, int 
sendto_flags, const struct osmo_sockaddr *dest)
+{
+       int rc;
+
+       OSMO_ASSERT(iofd->mode == OSMO_IO_FD_MODE_RECVFROM_SENDTO);
+
+       struct iofd_msghdr *msghdr = iofd_msghdr_alloc(iofd, IOFD_ACT_SENDTO, 
msg);
+       if (!msghdr)
+               return -ENOMEM;
+
+       if (dest) {
+               msghdr->osa = *dest;
+               msghdr->hdr.msg_name = &msghdr->osa.u.sa;
+               msghdr->hdr.msg_namelen = osmo_sockaddr_size(&msghdr->osa);
+       }
+       msghdr->flags = sendto_flags;
+       msghdr->iov[0].iov_base = msgb_data(msghdr->msg);
+       msghdr->iov[0].iov_len = msgb_length(msghdr->msg);
+       msghdr->hdr.msg_iov = &msghdr->iov[0];
+       msghdr->hdr.msg_iovlen = 1;
+
+       rc = iofd_txqueue_enqueue(iofd, msghdr);
+       if (rc < 0) {
+               iofd_msghdr_free(msghdr);
+               LOGPIO(iofd, LOGL_ERROR, "enqueueing message failed (%d). 
Rejecting msgb\n", rc);
+               return rc;
+       }
+
+       return 0;
+}
+
+/*! Enable reading from this iofd
+ *
+ *  \param[in] iofd the file descriptor
+ */
+void osmo_iofd_read_enable(struct osmo_io_fd *iofd)
+{
+       iofd->read_enabled = true;
+       osmo_iofd_ops.read_enable(iofd);
+}
+
+/*! Disable reading from this iofd
+ *
+ *  \param[in] iofd the file descriptor
+ */
+void osmo_iofd_read_disable(struct osmo_io_fd *iofd)
+{
+       iofd->read_enabled = false;
+       osmo_iofd_ops.read_disable(iofd);
+}
+
+/*! Enable writing to this iofd
+ *
+ *  \param[in] iofd the file descriptor
+ */
+void osmo_iofd_write_enable(struct osmo_io_fd *iofd)
+{
+       iofd->write_enabled = true;
+       if (iofd->tx_queue.current_length > 0)
+               osmo_iofd_ops.write_enable(iofd);
+}
+
+/*! Disable writing to this iofd
+ *
+ *  \param[in] iofd the file descriptor
+ */
+void osmo_iofd_write_disable(struct osmo_io_fd *iofd)
+{
+       iofd->write_enabled = false;
+       osmo_iofd_ops.write_disable(iofd);
+}
+
+/*! Allocate and setup a new iofd
+ *  \param[in] ctx the parent context from which to allocate
+ *  \param[in] fd the underlying system file descriptor
+ *  \param[in] name the name of the iofd
+ *  \param[in] mode the mode of the iofd, whether it should use 
read()/write(), sendto()/recvfrom()
+ *  \param[in] ioops structure with read/write/send/recv callbacks
+ *  \param[in] data user data pointer accessible by the ioops callbacks
+ *  \returns The newly allocated osmo_io_fd struct or NULL on failure
+ */
+struct osmo_io_fd *osmo_iofd_setup(const void *ctx, int fd, const char *name, 
enum osmo_io_fd_mode mode,
+                 const struct osmo_io_ops *ioops, void *data)
+{
+       struct osmo_io_fd *iofd = talloc_zero(ctx, struct osmo_io_fd);
+       if (!iofd)
+               return NULL;
+
+       iofd->fd = fd;
+       iofd->mode = mode;
+
+       iofd->name = talloc_strdup(iofd, name);
+
+       if (ioops)
+               iofd->io_ops = *ioops;
+
+       iofd->pending = NULL;
+
+       iofd->data = data;
+
+       iofd->msgb_alloc.ctx = ctx;
+       iofd->msgb_alloc.size = OSMO_IO_DEFAULT_MSGB_SIZE;
+       iofd->msgb_alloc.headroom = OSMO_IO_DEFAULT_MSGB_HEADROOM;
+
+       iofd->tx_queue.max_length = 32;
+       INIT_LLIST_HEAD(&iofd->tx_queue.msg_queue);
+
+       return iofd;
+}
+
+/*! Register the fd with the underlying backend
+ *
+ *  \param[in] iofd the iofd file descriptor
+ *  \param[in] fd the system fd number that will be registeres. If negative 
will use the one already set.
+ *  \returns zero on success, a negative value on error
+*/
+int osmo_iofd_register(struct osmo_io_fd *iofd, int fd)
+{
+       if (fd >= 0)
+               iofd->fd = fd;
+       iofd->closed = false;
+
+       if (osmo_iofd_ops.register_fd)
+               return osmo_iofd_ops.register_fd(iofd);
+
+       return 0;
+}
+
+/*! Unregister the fd from the underlying backend
+ *
+ *  \param[in] iofd the file descriptor
+ *  \returns zero on success, a negative value on error
+ */
+int osmo_iofd_unregister(struct osmo_io_fd *iofd)
+{
+       if (osmo_iofd_ops.unregister_fd)
+               return osmo_iofd_ops.unregister_fd(iofd);
+
+       return 0;
+}
+
+/*! Get the number of messages in the tx queue
+ *
+ *  \param[in] iofd the file descriptor
+ */
+unsigned int osmo_iofd_txqueue_len(struct osmo_io_fd *iofd)
+{
+       return iofd->tx_queue.current_length;
+}
+
+/*! Clear the transmit queue of the the iofd
+ *
+ *  This function frees all messages currently pending in the transmit queue
+ *  \param[in] iofd the file descriptor
+ */
+void osmo_iofd_txqueue_clear(struct osmo_io_fd *iofd)
+{
+       struct iofd_msghdr *hdr;
+       while ((hdr = iofd_txqueue_dequeue(iofd))) {
+               msgb_free(hdr->msg);
+               iofd_msghdr_free(hdr);
+       }
+}
+
+/*! Free the iofd
+ *
+ *  This function is safe to use in the read/write callbacks and will defer 
freeing it until safe to do so.
+ *  The iofd will be closed before.
+ *  \param[in] iofd the file descriptor
+ */
+void osmo_iofd_free(struct osmo_io_fd *iofd)
+{
+       if (!iofd)
+               return;
+
+       osmo_iofd_close(iofd);
+
+       if (!iofd->in_callback) {
+               talloc_free(iofd);
+       } else {
+               /* Prevent our parent context from freeing us prematurely */
+               talloc_steal(NULL, iofd);
+               iofd->to_free = true;
+       }
+}
+
+/*! Close the iofd
+ *
+ *  This function closes the underlying fd and clears any messages in the tx 
queue
+ *  The iofd is not freed and can be assigned a new file descriptor with 
osmo_iofd_register()
+ *  \param[in] iofd the file descriptor
+ *  \ returns 0 on success, a negative value otherwise
+ */
+int osmo_iofd_close(struct osmo_io_fd *iofd)
+{
+       int rc = 0;
+
+       if (iofd->closed)
+               return rc;
+
+       iofd->closed = true;
+
+       /* Free pending msgs in tx queue */
+       osmo_iofd_txqueue_clear(iofd);
+       msgb_free(iofd->pending);
+
+       iofd->pending = NULL;
+
+       if (osmo_iofd_ops.close)
+               rc = osmo_iofd_ops.close(iofd);
+       iofd->fd = -1;
+       return rc;
+}
+
+/*! Set the size and headroom of the msgb allocated when receiving messages
+ *  \param[in] size the size of the msgb when receiving data
+ *  \param[in] headroom the headroom of the msgb when receiving data
+ */
+void osmo_iofd_set_alloc_info(struct osmo_io_fd *iofd, unsigned int size, 
unsigned int headroom)
+{
+       iofd->msgb_alloc.headroom = headroom;
+       iofd->msgb_alloc.size = size;
+}
+
+/*! Get the associated user-data from an iofd
+ *  \param[in] iofd the file descriptor
+ *  \returns the data that was previously set with \ref osmo_iofd_setup()
+ */
+void *osmo_iofd_get_data(const struct osmo_io_fd *iofd)
+{
+       return iofd->data;
+}
+
+/*! Set the associated user-data from an iofd
+ *  \param[in] iofd the file descriptor
+ *  \param[in] data the data to set
+ */
+void osmo_iofd_set_data(struct osmo_io_fd *iofd, void *data)
+{
+       iofd->data = data;
+}
+
+/*! Get the private number from an iofd
+ *  \param[in] iofd the file descriptor
+ *  \returns the private number that was previously set with \ref 
osmo_iofd_set_priv_nr()
+ */
+unsigned int osmo_iofd_get_priv_nr(const struct osmo_io_fd *iofd)
+{
+       return iofd->priv_nr;
+}
+
+/*! Set the private number from an iofd
+ *  \param[in] iofd the file descriptor
+ *  \param[in] priv_nr the private number to set
+ */
+void osmo_iofd_set_priv_nr(struct osmo_io_fd *iofd, unsigned int priv_nr)
+{
+       iofd->priv_nr = priv_nr;
+}
+
+/*! Get the underlying file descriptor from an iofd
+ *  \param[in] iofd the file descriptor
+ *  \returns the underlying file descriptor number */
+int osmo_iofd_get_fd(const struct osmo_io_fd *iofd)
+{
+       return iofd->fd;
+}
+
+/*! Get the name of the file descriptor
+ *  \param[in] iofd the file descriptor
+ *  \returns the name of the iofd as given in \ref osmo_iofd_setup() */
+const char *osmo_iofd_get_name(const struct osmo_io_fd *iofd)
+{
+       return iofd->name;
+}
+
+#endif /* defined(__linux__) */
diff --git a/src/core/osmo_io_internal.h b/src/core/osmo_io_internal.h
new file mode 100644
index 0000000..7fc4b6b
--- /dev/null
+++ b/src/core/osmo_io_internal.h
@@ -0,0 +1,132 @@
+/*! \file osmo_io_internal.h */
+
+#pragma once
+
+#include <unistd.h>
+#include <stdbool.h>
+
+#include <osmocom/core/osmo_io.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/socket.h>
+
+#include "../config.h"
+
+#define OSMO_IO_DEFAULT_MSGB_SIZE 1024
+#define OSMO_IO_DEFAULT_MSGB_HEADROOM 128
+
+extern const struct iofd_backend_ops iofd_poll_ops;
+#define OSMO_IO_BACKEND_DEFAULT "POLL"
+
+struct iofd_backend_ops {
+       int (*register_fd)(struct osmo_io_fd *iofd);
+       int (*unregister_fd)(struct osmo_io_fd *iofd);
+       int (*close)(struct osmo_io_fd *iofd);
+       void (*write_enable)(struct osmo_io_fd *iofd);
+       void (*write_disable)(struct osmo_io_fd *iofd);
+       void (*read_enable)(struct osmo_io_fd *iofd);
+       void (*read_disable)(struct osmo_io_fd *iofd);
+};
+
+struct osmo_io_fd {
+       /*! linked list for internal management */
+       struct llist_head list;
+       /*! actual operating-system level file decriptor */
+       int fd;
+       /*! type of read/write mode to use */
+       enum osmo_io_fd_mode mode;
+
+       /*! flags to guard closing/freeing of iofd */
+       bool closed;
+       bool in_callback;
+       bool to_free;
+
+       bool write_enabled;
+       bool read_enabled;
+
+       /*! human-readable name to associte with fd */
+       const char *name;
+
+       /*! send/recv (msg) callback functions */
+       struct osmo_io_ops io_ops;
+       /*! Pending msgb to keep partial data during segmentation */
+       struct msgb *pending;
+
+       /*! data pointer passed through to call-back function */
+       void *data;
+       /*! private number, extending \a data */
+       unsigned int priv_nr;
+
+       struct {
+               /*! talloc context from which to allocate msgb when reading */
+               const void *ctx;
+               /*! size of msgb to allocate (excluding headroom) */
+               unsigned int size;
+               /*! headroom to allocate when allocating msgb's */
+               unsigned int headroom;
+       } msgb_alloc;
+
+       struct {
+               /*! maximum length of write queue */
+               unsigned int max_length;
+               /*! current length of write queue */
+               unsigned int current_length;
+               /*! actual linked list implementing the transmit queue */
+               struct llist_head msg_queue;
+       } tx_queue;
+
+       union {
+               struct {
+                       struct osmo_fd ofd;
+               } poll;
+               struct {
+                       bool read_enabled;
+                       bool read_pending;
+                       bool write_pending;
+                       bool write_enabled;
+                       /* TODO: index into array of registered fd's? */
+               } uring;
+       } u;
+};
+
+enum iofd_msg_action {
+       IOFD_ACT_READ,
+       IOFD_ACT_WRITE,
+       IOFD_ACT_RECVFROM,
+       IOFD_ACT_SENDTO,
+       // TODO: SCTP_*
+};
+
+
+/* serialized version of 'struct msghdr' employed by sendmsg/recvmsg */
+struct iofd_msghdr {
+       struct llist_head list;
+       enum iofd_msg_action action;
+       struct msghdr hdr;
+       struct osmo_sockaddr osa;
+       struct iovec iov[1];
+       int flags;
+
+       struct msgb *msg;
+       struct osmo_io_fd *iofd;
+};
+
+enum iofd_seg_act {
+       IOFD_SEG_ACT_HANDLE_ONE,
+       IOFD_SEG_ACT_HANDLE_MORE,
+       IOFD_SEG_ACT_DEFER,
+};
+
+struct iofd_msghdr *iofd_msghdr_alloc(struct osmo_io_fd *iofd, enum 
iofd_msg_action action, struct msgb *msg);
+void iofd_msghdr_free(struct iofd_msghdr *msghdr);
+
+struct msgb *iofd_msgb_alloc(struct osmo_io_fd *iofd);
+struct msgb *iofd_msgb_pending(struct osmo_io_fd *iofd);
+struct msgb *iofd_msgb_pending_or_alloc(struct osmo_io_fd *iofd);
+
+void iofd_handle_segmented_read(struct osmo_io_fd *iofd, struct msgb *msg, int 
rc);
+
+int iofd_txqueue_enqueue(struct osmo_io_fd *iofd, struct iofd_msghdr *msghdr);
+void iofd_txqueue_enqueue_front(struct osmo_io_fd *iofd, struct iofd_msghdr 
*msghdr);
+struct iofd_msghdr *iofd_txqueue_dequeue(struct osmo_io_fd *iofd);
diff --git a/src/core/osmo_io_poll.c b/src/core/osmo_io_poll.c
new file mode 100644
index 0000000..95aa84a
--- /dev/null
+++ b/src/core/osmo_io_poll.c
@@ -0,0 +1,185 @@
+/*! \file osmo_io_poll.c
+ * New osmocom async I/O API.
+ *
+ * (C) 2022 by Harald Welte <lafo...@osmocom.org>
+ * (C) 2022-2023 by sysmocom - s.f.m.c. GmbH <i...@sysmocom.de>
+ * Author: Daniel Willmann <dwillm...@sysmocom.de>
+ *
+ * All Rights Reserved.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program 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 General Public License for more details.
+ */
+
+#include "../config.h"
+#if defined(__linux__)
+
+#include <errno.h>
+#include <stdio.h>
+#include <talloc.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <sys/socket.h>
+
+#include <osmocom/core/osmo_io.h>
+#include <osmocom/core/linuxlist.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/msgb.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/socket.h>
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/utils.h>
+
+#include "osmo_io_internal.h"
+
+static void iofd_poll_ofd_cb_recvmsg_sendmsg(struct osmo_fd *ofd, unsigned int 
what)
+{
+       struct osmo_io_fd *iofd = ofd->data;
+       struct msgb *msg;
+       int rc, flags = 0;
+
+       if (what & OSMO_FD_READ) {
+               struct iofd_msghdr hdr;
+               msg = iofd_msgb_pending_or_alloc(iofd);
+               if (!msg) {
+                       LOGP(DLIO, LOGL_ERROR, "iofd(%s): Could not get msgb 
for reading\n", iofd->name);
+                       OSMO_ASSERT(0);
+               }
+
+               hdr.msg = msg;
+               hdr.iov[0].iov_base = msgb_data(msg);
+               hdr.iov[0].iov_len = msgb_tailroom(msg);
+               hdr.hdr.msg_iov = &hdr.iov[0];
+               hdr.hdr.msg_iovlen = 1;
+               hdr.hdr.msg_name = &hdr.osa.u.sa;
+               hdr.hdr.msg_namelen = osmo_sockaddr_size(&hdr.osa);
+
+               rc = recvmsg(ofd->fd, &hdr.hdr, flags);
+               if (rc > 0)
+                       msgb_put(msg, rc);
+
+               switch (iofd->mode) {
+               case OSMO_IO_FD_MODE_READ_WRITE:
+                       iofd_handle_segmented_read(iofd, msg, rc);
+                       break;
+               case OSMO_IO_FD_MODE_RECVFROM_SENDTO:
+                       iofd->io_ops.recvfrom_cb(iofd, rc, msg, &hdr.osa);
+                       break;
+               case OSMO_IO_FD_MODE_SCTP_RECVMSG_SENDMSG:
+                       /* TODO Implement */
+                       OSMO_ASSERT(false);
+                       break;
+               }
+       }
+
+       if (iofd->closed)
+               return;
+
+       if (what & OSMO_FD_WRITE) {
+               struct iofd_msghdr *msghdr = iofd_txqueue_dequeue(iofd);
+               if (msghdr) {
+                       msg = msghdr->msg;
+
+                       rc = sendmsg(ofd->fd, &msghdr->hdr, msghdr->flags);
+                       if (rc > 0 && rc < msgb_length(msg)) {
+                               msgb_pull(msg, rc);
+                               iofd_txqueue_enqueue_front(iofd, msghdr);
+                               return;
+                       }
+
+                       switch (iofd->mode) {
+                       case OSMO_IO_FD_MODE_READ_WRITE:
+                               iofd->io_ops.write_cb(iofd, rc, msg);
+                               break;
+                       case OSMO_IO_FD_MODE_RECVFROM_SENDTO:
+                               iofd->io_ops.sendto_cb(iofd, rc, msg, 
&msghdr->osa);
+                               break;
+                       case OSMO_IO_FD_MODE_SCTP_RECVMSG_SENDMSG:
+                               OSMO_ASSERT(false);
+                               break;
+                       }
+
+                       talloc_free(msghdr);
+                       msgb_free(msg);
+               }
+       }
+}
+
+static int iofd_poll_ofd_cb_dispatch(struct osmo_fd *ofd, unsigned int what)
+{
+       struct osmo_io_fd *iofd = ofd->data;
+
+       iofd->in_callback = true;
+       iofd_poll_ofd_cb_recvmsg_sendmsg(ofd, what);
+       iofd->in_callback = false;
+
+       if (iofd->to_free) {
+               talloc_free(iofd);
+               return 0;
+       }
+
+       return 0;
+}
+
+int iofd_poll_register(struct osmo_io_fd *iofd)
+{
+       struct osmo_fd *ofd = &iofd->u.poll.ofd;
+       osmo_fd_setup(ofd, iofd->fd, 0, &iofd_poll_ofd_cb_dispatch, iofd, 0);
+       return osmo_fd_register(ofd);
+}
+
+int iofd_poll_unregister(struct osmo_io_fd *iofd)
+{
+       struct osmo_fd *ofd = &iofd->u.poll.ofd;
+       osmo_fd_unregister(ofd);
+
+       return 0;
+}
+
+int iofd_poll_close(struct osmo_io_fd *iofd)
+{
+       osmo_fd_close(&iofd->u.poll.ofd);
+
+       return 0;
+}
+
+void iofd_poll_read_enable(struct osmo_io_fd *iofd)
+{
+       osmo_fd_read_enable(&iofd->u.poll.ofd);
+}
+
+void iofd_poll_read_disable(struct osmo_io_fd *iofd)
+{
+       osmo_fd_read_disable(&iofd->u.poll.ofd);
+}
+
+void iofd_poll_write_enable(struct osmo_io_fd *iofd)
+{
+       osmo_fd_write_enable(&iofd->u.poll.ofd);
+}
+
+void iofd_poll_write_disable(struct osmo_io_fd *iofd)
+{
+       osmo_fd_write_disable(&iofd->u.poll.ofd);
+}
+
+const struct iofd_backend_ops iofd_poll_ops = {
+       .register_fd = iofd_poll_register,
+       .unregister_fd = iofd_poll_unregister,
+       .close = iofd_poll_close,
+       .write_enable = iofd_poll_write_enable,
+       .write_disable = iofd_poll_write_disable,
+       .read_enable = iofd_poll_read_enable,
+       .read_disable = iofd_poll_read_disable,
+};
+
+#endif /* defined(__linux__) */
diff --git a/tests/logging/logging_vty_test.vty 
b/tests/logging/logging_vty_test.vty
index f9b4e01..da09be7 100644
--- a/tests/logging/logging_vty_test.vty
+++ b/tests/logging/logging_vty_test.vty
@@ -54,7 +54,7 @@
   logging print level (0|1)
   logging print file (0|1|basename) [last]
   logging set-log-mask MASK
-  logging level 
(aa|bb|ccc|dddd|eee|lglobal|llapd|linp|lmux|lmi|lmib|lsms|lctrl|lgtp|lstats|lgsup|loap|lss7|lsccp|lsua|lm3ua|lmgcp|ljibuf|lrspro|lns|lbssgp|lnsdata|lnssignal|liuup|lpfcp|lcsn1)
 (debug|info|notice|error|fatal)
+  logging level 
(aa|bb|ccc|dddd|eee|lglobal|llapd|linp|lmux|lmi|lmib|lsms|lctrl|lgtp|lstats|lgsup|loap|lss7|lsccp|lsua|lm3ua|lmgcp|ljibuf|lrspro|lns|lbssgp|lnsdata|lnssignal|liuup|lpfcp|lcsn1|lio)
 (debug|info|notice|error|fatal)
   logging level set-all (debug|info|notice|error|fatal)
   logging level force-all (debug|info|notice|error|fatal)
   no logging level force-all
@@ -568,7 +568,7 @@

 logging_vty_test# list
 ...
-  logp 
(aa|bb|ccc|dddd|eee|lglobal|llapd|linp|lmux|lmi|lmib|lsms|lctrl|lgtp|lstats|lgsup|loap|lss7|lsccp|lsua|lm3ua|lmgcp|ljibuf|lrspro|lns|lbssgp|lnsdata|lnssignal|liuup|lpfcp|lcsn1)
 (debug|info|notice|error|fatal) .LOGMESSAGE
+  logp 
(aa|bb|ccc|dddd|eee|lglobal|llapd|linp|lmux|lmi|lmib|lsms|lctrl|lgtp|lstats|lgsup|loap|lss7|lsccp|lsua|lm3ua|lmgcp|ljibuf|lrspro|lns|lbssgp|lnsdata|lnssignal|liuup|lpfcp|lcsn1|lio)
 (debug|info|notice|error|fatal) .LOGMESSAGE
 ...

 logging_vty_test# logp?
@@ -606,6 +606,7 @@
   liuup      Iu UP layer
   lpfcp      libosmo-pfcp Packet Forwarding Control Protocol
   lcsn1      libosmo-csn1 Concrete Syntax Notation 1 codec
+  lio        libosmocore IO Subsystem
 
 logging_vty_test# logp lglobal ?
   debug   Log debug messages and higher levels

--
To view, visit https://gerrit.osmocom.org/c/libosmocore/+/30934
To unsubscribe, or for help writing mail filters, visit 
https://gerrit.osmocom.org/settings

Gerrit-Project: libosmocore
Gerrit-Branch: master
Gerrit-Change-Id: I50d73cf550d6ce8154bf827bf47408131cf5b0a0
Gerrit-Change-Number: 30934
Gerrit-PatchSet: 18
Gerrit-Owner: daniel <dwillm...@sysmocom.de>
Gerrit-Reviewer: Hoernchen <ew...@sysmocom.de>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: daniel <dwillm...@sysmocom.de>
Gerrit-Reviewer: dexter <pma...@sysmocom.de>
Gerrit-Reviewer: fixeria <vyanits...@sysmocom.de>
Gerrit-Reviewer: laforge <lafo...@osmocom.org>
Gerrit-Reviewer: neels <nhofm...@sysmocom.de>
Gerrit-Reviewer: osmith <osm...@sysmocom.de>
Gerrit-Reviewer: pespin <pes...@sysmocom.de>
Gerrit-MessageType: merged

Reply via email to