diff options
Diffstat (limited to 'hw/char/terminal3270.c')
| -rw-r--r-- | hw/char/terminal3270.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/hw/char/terminal3270.c b/hw/char/terminal3270.c index bef3812c18..55eed5622a 100644 --- a/hw/char/terminal3270.c +++ b/hw/char/terminal3270.c @@ -12,16 +12,114 @@ */ #include "qemu/osdep.h" +#include "qapi/error.h" +#include "sysemu/char.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; + int out_len; + bool handshake_done; } 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; +} + +/* + * 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); +} + +/* + * 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)); + + 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 terminal_init(EmulatedCcw3270Device *dev, Error **errp) { + Terminal3270 *t = TERMINAL_3270(dev); static bool terminal_available; if (terminal_available) { @@ -29,13 +127,95 @@ static void terminal_init(EmulatedCcw3270Device *dev, Error **errp) return; } terminal_available = true; + qemu_chr_fe_set_handlers(&t->chr, terminal_can_read, + terminal_read, NULL, t, NULL, true); +} + +static int read_payload_3270(EmulatedCcw3270Device *dev, uint32_t cda, + uint16_t count) +{ + Terminal3270 *t = TERMINAL_3270(dev); + int len; + + len = MIN(count, t->in_len); + cpu_physical_memory_write(cda, 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, + uint32_t cda, uint16_t count) +{ + Terminal3270 *t = TERMINAL_3270(dev); + int retval = 0; + + assert(count <= (OUTPUT_BUFFER_SIZE - 3) / 2); + + if (!t->handshake_done) { + /* + * Before having finished 3270 negotiation, + * sending outbound data is prohibited. + */ + return 0; + } + if (!qemu_chr_fe_get_driver(&t->chr)) { + /* We just say we consumed all data if there's no backend. */ + return count; + } + t->outv[0] = cmd; + cpu_physical_memory_read(cda, &t->outv[1], count); + t->out_len = count + 1; + + t->out_len = insert_IAC_escape_char(t->outv, t->out_len); + t->outv[t->out_len++] = IAC; + t->outv[t->out_len++] = IAC_EOR; + + retval = qemu_chr_fe_write_all(&t->chr, t->outv, t->out_len); + return (retval <= 0) ? 0 : (retval - 3); +} + +static Property terminal_properties[] = { + DEFINE_PROP_CHR("chardev", Terminal3270, chr), + DEFINE_PROP_END_OF_LIST(), +}; + 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; ck->init = terminal_init; + ck->read_payload_3270 = read_payload_3270; + ck->write_payload_3270 = write_payload_3270; } static const TypeInfo ccw_terminal_info = { |