diff options
Diffstat (limited to 'hw/char/terminal3270.c')
| -rw-r--r-- | hw/char/terminal3270.c | 321 |
1 files changed, 321 insertions, 0 deletions
diff --git a/hw/char/terminal3270.c b/hw/char/terminal3270.c new file mode 100644 index 000000000..82e85fac2 --- /dev/null +++ b/hw/char/terminal3270.c @@ -0,0 +1,321 @@ +/* + * Terminal 3270 implementation + * + * Copyright 2017 IBM Corp. + * + * Authors: Yang Chen <bjcyang@linux.vnet.ibm.com> + * Jing Liu <liujbjl@linux.vnet.ibm.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or (at + * your option) any later version. See the COPYING file in the top-level + * directory. + */ + +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "qemu/module.h" +#include "chardev/char-fe.h" +#include "hw/qdev-properties.h" +#include "hw/qdev-properties-system.h" +#include "hw/s390x/3270-ccw.h" +#include "qom/object.h" + +/* Enough spaces for different window sizes. */ +#define INPUT_BUFFER_SIZE 1000 +/* + * 1 for header, 1024*2 for datastream, 2 for tail + * Reserve enough spaces for telnet IAC escape. + */ +#define OUTPUT_BUFFER_SIZE 2051 + +struct Terminal3270 { + EmulatedCcw3270Device cdev; + CharBackend chr; + uint8_t inv[INPUT_BUFFER_SIZE]; + uint8_t outv[OUTPUT_BUFFER_SIZE]; + int in_len; + bool handshake_done; + guint timer_tag; +}; +typedef struct Terminal3270 Terminal3270; + +#define TYPE_TERMINAL_3270 "x-terminal3270" +DECLARE_INSTANCE_CHECKER(Terminal3270, TERMINAL_3270, + TYPE_TERMINAL_3270) + +static int terminal_can_read(void *opaque) +{ + Terminal3270 *t = opaque; + + return INPUT_BUFFER_SIZE - t->in_len; +} + +static void terminal_timer_cancel(Terminal3270 *t) +{ + if (t->timer_tag) { + g_source_remove(t->timer_tag); + t->timer_tag = 0; + } +} + +/* + * Protocol handshake done, + * signal guest by an unsolicited DE irq. + */ +static void TN3270_handshake_done(Terminal3270 *t) +{ + CcwDevice *ccw_dev = CCW_DEVICE(t); + SubchDev *sch = ccw_dev->sch; + + t->handshake_done = true; + sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END; + css_conditional_io_interrupt(sch); +} + +/* + * Called when the interval is timeout to detect + * if the client is still alive by Timing Mark. + */ +static gboolean send_timing_mark_cb(gpointer opaque) +{ + Terminal3270 *t = opaque; + const uint8_t timing[] = {0xff, 0xfd, 0x06}; + + qemu_chr_fe_write_all(&t->chr, timing, sizeof(timing)); + return true; +} + +/* + * Receive inbound data from socket. + * For data given to guest, drop the data boundary IAC, IAC_EOR. + * TODO: + * Using "Reset" key on x3270 may result multiple commands in one packet. + * This usually happens when the user meets a poor traffic of the network. + * As of now, for such case, we simply terminate the connection, + * and we should come back here later with a better solution. + */ +static void terminal_read(void *opaque, const uint8_t *buf, int size) +{ + Terminal3270 *t = opaque; + CcwDevice *ccw_dev = CCW_DEVICE(t); + SubchDev *sch = ccw_dev->sch; + int end; + + assert(size <= (INPUT_BUFFER_SIZE - t->in_len)); + + terminal_timer_cancel(t); + t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t); + memcpy(&t->inv[t->in_len], buf, size); + t->in_len += size; + if (t->in_len < 2) { + return; + } + + if (!t->handshake_done) { + /* + * Receiving Terminal Type is the last step of handshake. + * The data format: IAC SB Terminal-Type IS <terminal type> IAC SE + * The code for Terminal-Type is 0x18, for IS is 0. + * Simply check the data format and mark handshake_done. + */ + if (t->in_len > 6 && t->inv[2] == 0x18 && t->inv[3] == 0x0 && + t->inv[t->in_len - 2] == IAC && t->inv[t->in_len - 1] == IAC_SE) { + TN3270_handshake_done(t); + t->in_len = 0; + } + return; + } + + for (end = 0; end < t->in_len - 1; end++) { + if (t->inv[end] == IAC && t->inv[end + 1] == IAC_EOR) { + break; + } + } + if (end == t->in_len - 2) { + /* Data is valid for consuming. */ + t->in_len -= 2; + sch->curr_status.scsw.dstat = SCSW_DSTAT_ATTENTION; + css_conditional_io_interrupt(sch); + } else if (end < t->in_len - 2) { + /* "Reset" key is used. */ + qemu_chr_fe_disconnect(&t->chr); + } else { + /* Gathering data. */ + return; + } +} + +static void chr_event(void *opaque, QEMUChrEvent event) +{ + Terminal3270 *t = opaque; + CcwDevice *ccw_dev = CCW_DEVICE(t); + SubchDev *sch = ccw_dev->sch; + + /* Ensure the initial status correct, always reset them. */ + t->in_len = 0; + t->handshake_done = false; + terminal_timer_cancel(t); + + switch (event) { + case CHR_EVENT_OPENED: + /* + * 3270 does handshake firstly by the negotiate options in + * char-socket.c. Once qemu receives the terminal-type of the + * client, mark handshake done and trigger everything rolling again. + */ + t->timer_tag = g_timeout_add_seconds(600, send_timing_mark_cb, t); + break; + case CHR_EVENT_CLOSED: + sch->curr_status.scsw.dstat = SCSW_DSTAT_DEVICE_END; + css_conditional_io_interrupt(sch); + break; + case CHR_EVENT_BREAK: + case CHR_EVENT_MUX_IN: + case CHR_EVENT_MUX_OUT: + /* Ignore */ + break; + } +} + +static void terminal_init(EmulatedCcw3270Device *dev, Error **errp) +{ + Terminal3270 *t = TERMINAL_3270(dev); + static bool terminal_available; + + if (terminal_available) { + error_setg(errp, "Multiple 3270 terminals are not supported."); + return; + } + terminal_available = true; + qemu_chr_fe_set_handlers(&t->chr, terminal_can_read, + terminal_read, chr_event, NULL, t, NULL, true); +} + +static inline CcwDataStream *get_cds(Terminal3270 *t) +{ + return &(CCW_DEVICE(&t->cdev)->sch->cds); +} + +static int read_payload_3270(EmulatedCcw3270Device *dev) +{ + Terminal3270 *t = TERMINAL_3270(dev); + int len; + int ret; + + len = MIN(ccw_dstream_avail(get_cds(t)), t->in_len); + ret = ccw_dstream_write_buf(get_cds(t), t->inv, len); + if (ret < 0) { + return ret; + } + t->in_len -= len; + + return len; +} + +/* TN3270 uses binary transmission, which needs escape IAC to IAC IAC */ +static int insert_IAC_escape_char(uint8_t *outv, int out_len) +{ + int IAC_num = 0, new_out_len, i, j; + + for (i = 0; i < out_len; i++) { + if (outv[i] == IAC) { + IAC_num++; + } + } + if (IAC_num == 0) { + return out_len; + } + new_out_len = out_len + IAC_num; + for (i = out_len - 1, j = new_out_len - 1; j > i && i >= 0; i--, j--) { + outv[j] = outv[i]; + if (outv[i] == IAC) { + outv[--j] = IAC; + } + } + return new_out_len; +} + +/* + * Write 3270 outbound to socket. + * Return the count of 3270 data field if succeeded, zero if failed. + */ +static int write_payload_3270(EmulatedCcw3270Device *dev, uint8_t cmd) +{ + Terminal3270 *t = TERMINAL_3270(dev); + int retval = 0; + int count = ccw_dstream_avail(get_cds(t)); + int bound = (OUTPUT_BUFFER_SIZE - 3) / 2; + int len = MIN(count, bound); + int out_len = 0; + + if (!t->handshake_done) { + if (!(t->outv[0] == IAC && t->outv[1] != IAC)) { + /* + * Before having finished 3270 negotiation, + * sending outbound data except protocol options is prohibited. + */ + return 0; + } + } + if (!qemu_chr_fe_backend_connected(&t->chr)) { + /* We just say we consumed all data if there's no backend. */ + return count; + } + + t->outv[out_len++] = cmd; + do { + retval = ccw_dstream_read_buf(get_cds(t), &t->outv[out_len], len); + if (retval < 0) { + return retval; + } + count = ccw_dstream_avail(get_cds(t)); + out_len += len; + + out_len = insert_IAC_escape_char(t->outv, out_len); + if (!count) { + t->outv[out_len++] = IAC; + t->outv[out_len++] = IAC_EOR; + } + retval = qemu_chr_fe_write_all(&t->chr, t->outv, out_len); + len = MIN(count, bound); + out_len = 0; + } while (len && retval >= 0); + return (retval <= 0) ? 0 : get_cds(t)->count; +} + +static Property terminal_properties[] = { + DEFINE_PROP_CHR("chardev", Terminal3270, chr), + DEFINE_PROP_END_OF_LIST(), +}; + +static const VMStateDescription terminal3270_vmstate = { + .name = TYPE_TERMINAL_3270, + .unmigratable = 1, +}; + +static void terminal_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + EmulatedCcw3270Class *ck = EMULATED_CCW_3270_CLASS(klass); + + device_class_set_props(dc, terminal_properties); + dc->vmsd = &terminal3270_vmstate; + ck->init = terminal_init; + ck->read_payload_3270 = read_payload_3270; + ck->write_payload_3270 = write_payload_3270; +} + +static const TypeInfo ccw_terminal_info = { + .name = TYPE_TERMINAL_3270, + .parent = TYPE_EMULATED_CCW_3270, + .instance_size = sizeof(Terminal3270), + .class_init = terminal_class_init, + .class_size = sizeof(EmulatedCcw3270Class), +}; + +static void register_types(void) +{ + type_register_static(&ccw_terminal_info); +} + +type_init(register_types) |