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GET /api/1.1/patches/1525/?format=api
{ "id": 1525, "url": "https://patchwork.libcamera.org/api/1.1/patches/1525/?format=api", "web_url": "https://patchwork.libcamera.org/patch/1525/", "project": { "id": 1, "url": "https://patchwork.libcamera.org/api/1.1/projects/1/?format=api", "name": "libcamera", "link_name": "libcamera", "list_id": "libcamera_core", "list_email": "libcamera-devel@lists.libcamera.org", "web_url": "", "scm_url": "", "webscm_url": "" }, "msgid": "<20190627020955.6166-2-niklas.soderlund@ragnatech.se>", "date": "2019-06-27T02:09:54", "name": "[libcamera-devel,1/2] libcamera: ipc: unix: Add a IPC mechanism based on Unix sockets", "commit_ref": null, "pull_url": null, "state": "superseded", "archived": false, "hash": "497d2f4420ab24f7889e1ab410d9238fe6b3bb19", "submitter": { "id": 5, "url": "https://patchwork.libcamera.org/api/1.1/people/5/?format=api", "name": "Niklas Söderlund", "email": "niklas.soderlund@ragnatech.se" }, "delegate": null, "mbox": "https://patchwork.libcamera.org/patch/1525/mbox/", "series": [ { "id": 379, "url": "https://patchwork.libcamera.org/api/1.1/series/379/?format=api", "web_url": "https://patchwork.libcamera.org/project/libcamera/list/?series=379", "date": "2019-06-27T02:09:53", "name": "libcamera: ipc: unix: Add a IPC mechanism based on Unix sockets", "version": 1, "mbox": "https://patchwork.libcamera.org/series/379/mbox/" } ], "comments": "https://patchwork.libcamera.org/api/patches/1525/comments/", "check": "pending", "checks": "https://patchwork.libcamera.org/api/patches/1525/checks/", "tags": {}, "headers": { "Return-Path": "<niklas.soderlund@ragnatech.se>", "Received": [ "from bin-mail-out-05.binero.net (bin-mail-out-05.binero.net\n\t[195.74.38.228])\n\tby lancelot.ideasonboard.com (Postfix) with ESMTPS id 7D3F46192A\n\tfor <libcamera-devel@lists.libcamera.org>;\n\tThu, 27 Jun 2019 04:10:10 +0200 (CEST)", "from bismarck.berto.se (unknown [145.14.112.32])\n\tby bin-vsp-out-01.atm.binero.net (Halon) with ESMTPA\n\tid a53dec57-9880-11e9-8ab4-005056917a89;\n\tThu, 27 Jun 2019 04:09:51 +0200 (CEST)" ], "X-Halon-ID": "a53dec57-9880-11e9-8ab4-005056917a89", "Authorized-sender": "niklas@soderlund.pp.se", "From": "=?utf-8?q?Niklas_S=C3=B6derlund?= <niklas.soderlund@ragnatech.se>", "To": "libcamera-devel@lists.libcamera.org", "Date": "Thu, 27 Jun 2019 04:09:54 +0200", "Message-Id": "<20190627020955.6166-2-niklas.soderlund@ragnatech.se>", "X-Mailer": "git-send-email 2.21.0", "In-Reply-To": "<20190627020955.6166-1-niklas.soderlund@ragnatech.se>", "References": "<20190627020955.6166-1-niklas.soderlund@ragnatech.se>", "MIME-Version": "1.0", "Content-Type": "text/plain; charset=UTF-8", "Content-Transfer-Encoding": "8bit", "Subject": "[libcamera-devel] [PATCH 1/2] libcamera: ipc: unix: Add a IPC\n\tmechanism based on Unix sockets", "X-BeenThere": "libcamera-devel@lists.libcamera.org", "X-Mailman-Version": "2.1.23", "Precedence": "list", "List-Id": "<libcamera-devel.lists.libcamera.org>", "List-Unsubscribe": "<https://lists.libcamera.org/options/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=unsubscribe>", "List-Archive": "<https://lists.libcamera.org/pipermail/libcamera-devel/>", "List-Post": "<mailto:libcamera-devel@lists.libcamera.org>", "List-Help": "<mailto:libcamera-devel-request@lists.libcamera.org?subject=help>", "List-Subscribe": "<https://lists.libcamera.org/listinfo/libcamera-devel>,\n\t<mailto:libcamera-devel-request@lists.libcamera.org?subject=subscribe>", "X-List-Received-Date": "Thu, 27 Jun 2019 02:10:10 -0000" }, "content": "To be able to isolate an IPA component in a separate process an IPC\nmechanism is needed to communicate with it. Add an IPC mechanism based\non Unix sockets which allows users to pass both data and file descriptors\nto and from the IPA process.\n\nThe implementation allows users to send both data and file descriptors\nin the same message. This allows users to more easily implement\nserialization and deserialization of objects as all elements belonging\nto an object can be sent in one message.\n\nSigned-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>\n---\n src/libcamera/include/ipc_unixsocket.h | 59 +++++\n src/libcamera/ipc_unixsocket.cpp | 288 +++++++++++++++++++++++++\n src/libcamera/meson.build | 2 +\n 3 files changed, 349 insertions(+)\n create mode 100644 src/libcamera/include/ipc_unixsocket.h\n create mode 100644 src/libcamera/ipc_unixsocket.cpp", "diff": "diff --git a/src/libcamera/include/ipc_unixsocket.h b/src/libcamera/include/ipc_unixsocket.h\nnew file mode 100644\nindex 0000000000000000..68edbe72e2af1298\n--- /dev/null\n+++ b/src/libcamera/include/ipc_unixsocket.h\n@@ -0,0 +1,59 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * ipc_unixsocket.h - IPC mechanism based on Unix sockets\n+ */\n+\n+#ifndef __LIBCAMERA_IPC_UNIXSOCKET_H__\n+#define __LIBCAMERA_IPC_UNIXSOCKET_H__\n+\n+#include <cstdint>\n+#include <sys/types.h>\n+#include <vector>\n+\n+#include <libcamera/event_notifier.h>\n+\n+namespace libcamera {\n+\n+class IPCUnixSocket\n+{\n+public:\n+\tstruct Payload {\n+\t\tstd::vector<uint8_t> data;\n+\t\tstd::vector<int32_t> fds;\n+\t};\n+\n+\tIPCUnixSocket();\n+\n+\tint create();\n+\tint attach(int fd);\n+\tvoid close();\n+\n+\tSignal<const Payload &> payloadReceived;\n+\n+\tint send(Payload &payload);\n+\n+private:\n+\tstruct Header {\n+\t\tuint32_t data;\n+\t\tuint8_t fds;\n+\t};\n+\n+\tint configure();\n+\n+\tint sendData(void *buffer, size_t length, const int32_t *fds, unsigned int num);\n+\n+\tint recv();\n+\tint recvData(void *buffer, size_t length, int32_t *fds, unsigned int num);\n+\n+\tvoid dataNotifier(EventNotifier *notifier);\n+\n+\tint fd_;\n+\tbool master_;\n+\tEventNotifier *notifier_;\n+};\n+\n+} /* namespace libcamera */\n+\n+#endif /* __LIBCAMERA_IPC_UNIXSOCKET_H__ */\ndiff --git a/src/libcamera/ipc_unixsocket.cpp b/src/libcamera/ipc_unixsocket.cpp\nnew file mode 100644\nindex 0000000000000000..7b3d8995374dac1e\n--- /dev/null\n+++ b/src/libcamera/ipc_unixsocket.cpp\n@@ -0,0 +1,288 @@\n+/* SPDX-License-Identifier: LGPL-2.1-or-later */\n+/*\n+ * Copyright (C) 2019, Google Inc.\n+ *\n+ * ipc_unixsocket.cpp - IPC mechanism based on Unix sockets\n+ */\n+\n+#include \"ipc_unixsocket.h\"\n+\n+#include <string.h>\n+#include <sys/socket.h>\n+#include <unistd.h>\n+\n+#include \"log.h\"\n+\n+/**\n+ * \\file ipc_unixsocket.h\n+ * \\brief IPC mechanism based on Unix sockets\n+ */\n+\n+namespace libcamera {\n+\n+LOG_DEFINE_CATEGORY(IPCUnixSocket)\n+\n+/**\n+ * \\struct IPCUnixSocket::Payload\n+ * \\brief Container for an IPC payload\n+ *\n+ * Holds an array of bytes and an array of file descriptors that can be\n+ * transported across a IPC boundary.\n+ */\n+\n+/**\n+ * \\var IPCUnixSocket::Payload::data\n+ * \\brief Array of bytes to cross IPC boundary\n+ */\n+\n+/**\n+ * \\var IPCUnixSocket::Payload::fds\n+ * \\brief Array of file descriptors to cross IPC boundary\n+ */\n+\n+/**\n+ * \\class IPCUnixSocket\n+ * \\brief IPC mechanism based on Unix sockets\n+ *\n+ * The IPC mechanism provided by libcamera are centred around passing arrays of\n+ * raw bytes and file descriptors between processes. The primary users of the\n+ * IPC objects are pipeline handlers and Image Processing Algorithms components.\n+ * A pipeline handler would act as an IPC master and send messages for an IPA to\n+ * process and react to.\n+ *\n+ * The IPC design is asynchronous, a message is queued to a receiver which gets\n+ * notified that a message is ready to be consumed by a signal. The queuer of\n+ * the message gets no notification when a message is delivers nor processed.\n+ * If such interactions are needed a protocol specific to the users use-case\n+ * should be implemented on top of the IPC objects.\n+ *\n+ * The IPC design can transmit messages in any direction and the only difference\n+ * from a master and slave operation is how they are created and attached to one\n+ * another. After the two parts are setup the operation to send and receive\n+ * messages are the same for both.\n+ */\n+\n+IPCUnixSocket::IPCUnixSocket()\n+\t: fd_(-1), master_(false), notifier_(nullptr)\n+{\n+}\n+\n+/**\n+ * \\brief Create an new IPC channel\n+ *\n+ * Create a new IPC channel. Returned on success is a file descriptor which\n+ * needs to be passed to the slave process and used when attaching to the IPC\n+ * channel using attach().\n+ *\n+ * \\return A file descriptor on success, negative error code on failure\n+ */\n+int IPCUnixSocket::create()\n+{\n+\tint sockets[2];\n+\tint ret;\n+\n+\tret = socketpair(AF_UNIX, SOCK_DGRAM, 0, sockets);\n+\tif (ret) {\n+\t\tret = -errno;\n+\t\tLOG(IPCUnixSocket, Error)\n+\t\t\t<< \"Failed to create socket pair: \" << strerror(-ret);\n+\t\treturn ret;\n+\t}\n+\n+\tfd_ = sockets[0];\n+\tmaster_ = true;\n+\n+\tret = configure();\n+\tif (ret)\n+\t\treturn ret;\n+\n+\treturn sockets[1];\n+}\n+\n+/**\n+ * \\brief Attach to an existing IPC channel\n+ * \\param[in] fd File descriptor\n+ *\n+ * Attach to an existing IPC channel. The \\a fd argument is the file descriptor\n+ * returned from create() in the master process and passed to the slave process\n+ * to be able to establish the IPC channel.\n+ *\n+ * \\return 0 on success or a negative error code otherwise\n+ */\n+int IPCUnixSocket::attach(int fd)\n+{\n+\tfd_ = fd;\n+\n+\treturn configure();\n+}\n+\n+/**\n+ * \\brief Close the IPC channel\n+ *\n+ * Close the IPC channel, no communication is possible after close() have been\n+ * called.\n+ */\n+void IPCUnixSocket::close()\n+{\n+\tdelete notifier_;\n+\n+\tif (fd_ == -1)\n+\t\treturn;\n+\n+\t::close(fd_);\n+\n+\tfd_ = -1;\n+}\n+\n+/**\n+ * \\brief Send a message payload\n+ * \\param[in] payload Message payload to send\n+ *\n+ * Queues the message payload for transmission to the other end of the IPC\n+ * channel.\n+ *\n+ * \\return 0 on success or a negative error code otherwise\n+ */\n+int IPCUnixSocket::send(Payload &payload)\n+{\n+\tHeader hdr;\n+\tint ret;\n+\n+\tif (fd_ < 0)\n+\t\treturn -ENOTCONN;\n+\n+\thdr.data = payload.data.size();\n+\thdr.fds = payload.fds.size();\n+\n+\tret = ::send(fd_, &hdr, sizeof(hdr), 0);\n+\tif (ret < 0) {\n+\t\tret = -errno;\n+\t\tLOG(IPCUnixSocket, Error)\n+\t\t\t<< \"Failed to send: \" << strerror(-ret);\n+\t\treturn ret;\n+\t}\n+\n+\tret = sendData(payload.data.data(), hdr.data, payload.fds.data(), hdr.fds);\n+\tif (ret)\n+\t\treturn ret;\n+\n+\treturn 0;\n+}\n+\n+/**\n+ * \\var IPCUnixSocket::payloadReceived\n+ * \\brief A Signal emitted when a message payload is received\n+ */\n+\n+int IPCUnixSocket::configure()\n+{\n+\tnotifier_ = new EventNotifier(fd_, EventNotifier::Read);\n+\tnotifier_->activated.connect(this, &IPCUnixSocket::dataNotifier);\n+\n+\treturn 0;\n+}\n+\n+int IPCUnixSocket::sendData(void *buffer, size_t length, const int32_t *fds, unsigned int num)\n+{\n+\tstruct iovec iov[1];\n+\tiov[0].iov_base = buffer;\n+\tiov[0].iov_len = length;\n+\n+\tchar buf[CMSG_SPACE(num * sizeof(uint32_t))];\n+\tmemset(buf, 0, sizeof(buf));\n+\n+\tstruct cmsghdr *cmsg = (struct cmsghdr *)buf;\n+\tcmsg->cmsg_len = CMSG_LEN(num * sizeof(uint32_t));\n+\tcmsg->cmsg_level = SOL_SOCKET;\n+\tcmsg->cmsg_type = SCM_RIGHTS;\n+\n+\tstruct msghdr msg;\n+\tmsg.msg_name = nullptr;\n+\tmsg.msg_namelen = 0;\n+\tmsg.msg_iov = iov;\n+\tmsg.msg_iovlen = 1;\n+\tmsg.msg_control = cmsg;\n+\tmsg.msg_controllen = cmsg->cmsg_len;\n+\tmsg.msg_flags = 0;\n+\tmemcpy(CMSG_DATA(cmsg), fds, num * sizeof(uint32_t));\n+\n+\tif (sendmsg(fd_, &msg, 0) < 0) {\n+\t\tint ret = -errno;\n+\t\tLOG(IPCUnixSocket, Error)\n+\t\t\t<< \"Failed to sendmsg: \" << strerror(-ret);\n+\t\treturn ret;\n+\t}\n+\n+\treturn 0;\n+}\n+\n+int IPCUnixSocket::recv()\n+{\n+\tPayload payload;\n+\tHeader hdr;\n+\tint ret;\n+\n+\tif (fd_ < 0)\n+\t\treturn -ENOTCONN;\n+\n+\tret = ::recv(fd_, &hdr, sizeof(hdr), 0);\n+\tif (ret < 0) {\n+\t\tret = -errno;\n+\t\tLOG(IPCUnixSocket, Error)\n+\t\t\t<< \"Failed to recv header: \" << strerror(-ret);\n+\t\treturn ret;\n+\t}\n+\n+\tpayload.data.resize(hdr.data);\n+\tpayload.fds.resize(hdr.fds);\n+\n+\tret = recvData(payload.data.data(), hdr.data, payload.fds.data(), hdr.fds);\n+\tif (ret)\n+\t\treturn ret;\n+\n+\tpayloadReceived.emit(payload);\n+\n+\treturn 0;\n+}\n+\n+int IPCUnixSocket::recvData(void *buffer, size_t length, int32_t *fds, unsigned int num)\n+{\n+\tstruct iovec iov[1];\n+\tiov[0].iov_base = buffer;\n+\tiov[0].iov_len = length;\n+\n+\tchar buf[CMSG_SPACE(num * sizeof(uint32_t))];\n+\tmemset(buf, 0, sizeof(buf));\n+\n+\tstruct cmsghdr *cmsg = (struct cmsghdr *)buf;\n+\tcmsg->cmsg_len = CMSG_LEN(num * sizeof(uint32_t));\n+\tcmsg->cmsg_level = SOL_SOCKET;\n+\tcmsg->cmsg_type = SCM_RIGHTS;\n+\n+\tstruct msghdr msg;\n+\tmsg.msg_name = nullptr;\n+\tmsg.msg_namelen = 0;\n+\tmsg.msg_iov = iov;\n+\tmsg.msg_iovlen = 1;\n+\tmsg.msg_control = cmsg;\n+\tmsg.msg_controllen = cmsg->cmsg_len;\n+\tmsg.msg_flags = 0;\n+\n+\tif (recvmsg(fd_, &msg, 0) < 0) {\n+\t\tint ret = -errno;\n+\t\tLOG(IPCUnixSocket, Error)\n+\t\t\t<< \"Failed to recvmsg: \" << strerror(-ret);\n+\t\treturn ret;\n+\t}\n+\n+\tmemcpy(fds, CMSG_DATA(cmsg), num * sizeof(uint32_t));\n+\n+\treturn 0;\n+}\n+\n+void IPCUnixSocket::dataNotifier(EventNotifier *notifier)\n+{\n+\trecv();\n+}\n+\n+} /* namespace libcamera */\ndiff --git a/src/libcamera/meson.build b/src/libcamera/meson.build\nindex 985aa7e8ab0eb6ce..45bd9d1793aa0b19 100644\n--- a/src/libcamera/meson.build\n+++ b/src/libcamera/meson.build\n@@ -13,6 +13,7 @@ libcamera_sources = files([\n 'ipa_interface.cpp',\n 'ipa_manager.cpp',\n 'ipa_module.cpp',\n+ 'ipc_unixsocket.cpp',\n 'log.cpp',\n 'media_device.cpp',\n 'media_object.cpp',\n@@ -38,6 +39,7 @@ libcamera_headers = files([\n 'include/formats.h',\n 'include/ipa_manager.h',\n 'include/ipa_module.h',\n+ 'include/ipc_unixsocket.h',\n 'include/log.h',\n 'include/media_device.h',\n 'include/media_object.h',\n", "prefixes": [ "libcamera-devel", "1/2" ] }