include/io/channel-command.h

   1 /*
   2  * QEMU I/O channels external command driver
   3  *
   4  * Copyright (c) 2015 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #ifndef QIO_CHANNEL_COMMAND_H__
  22 #define QIO_CHANNEL_COMMAND_H__
  23
  24 #include "io/channel.h"
  25
  26 #define TYPE_QIO_CHANNEL_COMMAND "qio-channel-command"
  27 #define QIO_CHANNEL_COMMAND(obj)                                     \
  28     OBJECT_CHECK(QIOChannelCommand, (obj), TYPE_QIO_CHANNEL_COMMAND)
  29
  30 typedef struct QIOChannelCommand QIOChannelCommand;
  31
  32
  33 /**
  34  * QIOChannelCommand:
  35  *
  36  * The QIOChannelCommand class provides a channel implementation
  37  * that can transport data with an externally running command
  38  * via its stdio streams.
  39  */
  40
  41 struct QIOChannelCommand {
  42     QIOChannel parent;
  43     int writefd;
  44     int readfd;
  45     pid_t pid;
  46 };
  47
  48
  49 /**
  50  * qio_channel_command_new_pid:
  51  * @writefd: the FD connected to the command's stdin
  52  * @readfd: the FD connected to the command's stdout
  53  * @pid: the PID of the running child command
  54  * @errp: pointer to a NULL-initialized error object
  55  *
  56  * Create a channel for performing I/O with the
  57  * previously spawned command identified by @pid.
  58  * The two file descriptors provide the connection
  59  * to command's stdio streams, either one or which
  60  * may be -1 to indicate that stream is not open.
  61  *
  62  * The channel will take ownership of the process
  63  * @pid and will kill it when closing the channel.
  64  * Similarly it will take responsibility for
  65  * closing the file descriptors @writefd and @readfd.
  66  *
  67  * Returns: the command channel object, or NULL on error
  68  */
  69 QIOChannelCommand *
  70 qio_channel_command_new_pid(int writefd,
  71                             int readfd,
  72                             pid_t pid);
  73
  74 /**
  75  * qio_channel_command_new_spawn:
  76  * @argv: the NULL terminated list of command arguments
  77  * @flags: the I/O mode, one of O_RDONLY, O_WRONLY, O_RDWR
  78  * @errp: pointer to a NULL-initialized error object
  79  *
  80  * Create a channel for performing I/O with the
  81  * command to be spawned with arguments @argv.
  82  *
  83  * Returns: the command channel object, or NULL on error
  84  */
  85 QIOChannelCommand *
  86 qio_channel_command_new_spawn(const char *const argv[],
  87                               int flags,
  88                               Error **errp);
  89
  90
  91 #endif /* QIO_CHANNEL_COMMAND_H__ */