/* * Terminal 3270 implementation * * Copyright 2017 IBM Corp. * * Authors: Yang Chen * Jing Liu * * 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/s390x/3270-ccw.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 typedef 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; } Terminal3270; #define TYPE_TERMINAL_3270 "x-terminal3270" #define TERMINAL_3270(obj) \ OBJECT_CHECK(Terminal3270, (obj), 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 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, int 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; len = MIN(ccw_dstream_avail(get_cds(t)), t->in_len); ccw_dstream_write_buf(get_cds(t), t->inv, len); 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 { ccw_dstream_read_buf(get_cds(t), &t->outv[out_len], len); 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); dc->props = 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)