usr/src/cmd/bhyve/uart_emul.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2012 NetApp, Inc.
   5  * Copyright (c) 2013 Neel Natu <neel@freebsd.org>
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD$
  30  *
  31  */
  32 /*
  33  * This file and its contents are supplied under the terms of the
  34  * Common Development and Distribution License ("CDDL"), version 1.0.
  35  * You may only use this file in accordance with the terms of version
  36  * 1.0 of the CDDL.
  37  *
  38  * A full copy of the text of the CDDL should have accompanied this
  39  * source.  A copy of the CDDL is also available via the Internet at
  40  * http://www.illumos.org/license/CDDL.
  41  *
  42  * Copyright 2015 Pluribus Networks Inc.
  43  * Copyright 2018 Joyent, Inc.
  44  */
  45
  46 #include <sys/cdefs.h>
  47 __FBSDID("$FreeBSD$");
  48
  49 #include <sys/types.h>
  50 #include <dev/ic/ns16550.h>
  51 #ifndef WITHOUT_CAPSICUM
  52 #include <sys/capsicum.h>
  53 #include <capsicum_helpers.h>
  54 #endif
  55
  56 #include <stdio.h>
  57 #include <stdlib.h>
  58 #include <assert.h>
  59 #include <err.h>
  60 #include <errno.h>
  61 #include <fcntl.h>
  62 #include <termios.h>
  63 #include <unistd.h>
  64 #include <stdbool.h>
  65 #include <string.h>
  66 #include <pthread.h>
  67 #include <sysexits.h>
  68 #ifndef __FreeBSD__
  69 #include <sys/socket.h>
  70 #endif
  71
  72 #include "mevent.h"
  73 #include "uart_emul.h"
  74 #include "debug.h"
  75
  76 #define COM1_BASE       0x3F8
  77 #define COM1_IRQ        4
  78 #define COM2_BASE       0x2F8
  79 #define COM2_IRQ        3
  80 #define COM3_BASE       0x3E8
  81 #define COM3_IRQ        4
  82 #define COM4_BASE       0x2E8
  83 #define COM4_IRQ        3
  84
  85 #define DEFAULT_RCLK    1843200
  86 #define DEFAULT_BAUD    9600
  87
  88 #define FCR_RX_MASK     0xC0
  89
  90 #define MCR_OUT1        0x04
  91 #define MCR_OUT2        0x08
  92
  93 #define MSR_DELTA_MASK  0x0f
  94
  95 #ifndef REG_SCR
  96 #define REG_SCR         com_scr
  97 #endif
  98
  99 #define FIFOSZ  16
 100
 101 static bool uart_stdio;         /* stdio in use for i/o */
 102 static struct termios tio_stdio_orig;
 103
 104 static struct {
 105         int     baseaddr;
 106         int     irq;
 107         bool    inuse;
 108 } uart_lres[] = {
 109         { COM1_BASE, COM1_IRQ, false},
 110         { COM2_BASE, COM2_IRQ, false},
 111         { COM3_BASE, COM3_IRQ, false},
 112         { COM4_BASE, COM4_IRQ, false},
 113 };
 114
 115 #define UART_NLDEVS     (sizeof(uart_lres) / sizeof(uart_lres[0]))
 116
 117 struct fifo {
 118         uint8_t buf[FIFOSZ];
 119         int     rindex;         /* index to read from */
 120         int     windex;         /* index to write to */
 121         int     num;            /* number of characters in the fifo */
 122         int     size;           /* size of the fifo */
 123 };
 124
 125 struct ttyfd {
 126         bool    opened;
 127         int     rfd;            /* fd for reading */
 128         int     wfd;            /* fd for writing, may be == rfd */
 129 };
 130
 131 struct uart_softc {
 132         pthread_mutex_t mtx;    /* protects all softc elements */
 133         uint8_t data;           /* Data register (R/W) */
 134         uint8_t ier;            /* Interrupt enable register (R/W) */
 135         uint8_t lcr;            /* Line control register (R/W) */
 136         uint8_t mcr;            /* Modem control register (R/W) */
 137         uint8_t lsr;            /* Line status register (R/W) */
 138         uint8_t msr;            /* Modem status register (R/W) */
 139         uint8_t fcr;            /* FIFO control register (W) */
 140         uint8_t scr;            /* Scratch register (R/W) */
 141
 142         uint8_t dll;            /* Baudrate divisor latch LSB */
 143         uint8_t dlh;            /* Baudrate divisor latch MSB */
 144
 145         struct fifo rxfifo;
 146         struct mevent *mev;
 147
 148         struct ttyfd tty;
 149 #ifndef __FreeBSD__
 150         bool    sock;
 151         struct {
 152                 int     clifd;          /* console client unix domain socket */
 153                 int     servfd;         /* console server unix domain socket */
 154                 struct mevent *servmev; /* mevent for server socket */
 155         } usc_sock;
 156 #endif
 157
 158         bool    thre_int_pending;       /* THRE interrupt pending */
 159
 160         void    *arg;
 161         uart_intr_func_t intr_assert;
 162         uart_intr_func_t intr_deassert;
 163 };
 164
 165 static void uart_drain(int fd, enum ev_type ev, void *arg);
 166
 167 static void
 168 ttyclose(void)
 169 {
 170
 171         tcsetattr(STDIN_FILENO, TCSANOW, &tio_stdio_orig);
 172 }
 173
 174 static void
 175 ttyopen(struct ttyfd *tf)
 176 {
 177         struct termios orig, new;
 178
 179         tcgetattr(tf->rfd, &orig);
 180         new = orig;
 181         cfmakeraw(&new);
 182         new.c_cflag |= CLOCAL;
 183         tcsetattr(tf->rfd, TCSANOW, &new);
 184         if (uart_stdio) {
 185                 tio_stdio_orig = orig;
 186                 atexit(ttyclose);
 187         }
 188         raw_stdio = 1;
 189 }
 190
 191 static int
 192 ttyread(struct ttyfd *tf)
 193 {
 194         unsigned char rb;
 195
 196         if (read(tf->rfd, &rb, 1) == 1)
 197                 return (rb);
 198         else
 199                 return (-1);
 200 }
 201
 202 static void
 203 ttywrite(struct ttyfd *tf, unsigned char wb)
 204 {
 205
 206         (void)write(tf->wfd, &wb, 1);
 207 }
 208
 209 #ifndef __FreeBSD__
 210 static void
 211 sockwrite(struct uart_softc *sc, unsigned char wb)
 212 {
 213         (void) write(sc->usc_sock.clifd, &wb, 1);
 214 }
 215 #endif
 216
 217 static void
 218 rxfifo_reset(struct uart_softc *sc, int size)
 219 {
 220         char flushbuf[32];
 221         struct fifo *fifo;
 222         ssize_t nread;
 223         int error;
 224
 225         fifo = &sc->rxfifo;
 226         bzero(fifo, sizeof(struct fifo));
 227         fifo->size = size;
 228
 229         if (sc->tty.opened) {
 230                 /*
 231                  * Flush any unread input from the tty buffer.
 232                  */
 233                 while (1) {
 234                         nread = read(sc->tty.rfd, flushbuf, sizeof(flushbuf));
 235                         if (nread != sizeof(flushbuf))
 236                                 break;
 237                 }
 238
 239                 /*
 240                  * Enable mevent to trigger when new characters are available
 241                  * on the tty fd.
 242                  */
 243                 error = mevent_enable(sc->mev);
 244                 assert(error == 0);
 245         }
 246 #ifndef __FreeBSD__
 247         if (sc->sock && sc->usc_sock.clifd != -1) {
 248                 /* Flush any unread input from the socket buffer. */
 249                 do {
 250                         nread = read(sc->usc_sock.clifd, flushbuf,
 251                             sizeof (flushbuf));
 252                 } while (nread == sizeof (flushbuf));
 253
 254                 /* Enable mevent to trigger when new data available on sock */
 255                 error = mevent_enable(sc->mev);
 256                 assert(error == 0);
 257         }
 258 #endif /* __FreeBSD__ */
 259 }
 260
 261 static int
 262 rxfifo_available(struct uart_softc *sc)
 263 {
 264         struct fifo *fifo;
 265
 266         fifo = &sc->rxfifo;
 267         return (fifo->num < fifo->size);
 268 }
 269
 270 static int
 271 rxfifo_putchar(struct uart_softc *sc, uint8_t ch)
 272 {
 273         struct fifo *fifo;
 274         int error;
 275
 276         fifo = &sc->rxfifo;
 277
 278         if (fifo->num < fifo->size) {
 279                 fifo->buf[fifo->windex] = ch;
 280                 fifo->windex = (fifo->windex + 1) % fifo->size;
 281                 fifo->num++;
 282                 if (!rxfifo_available(sc)) {
 283                         if (sc->tty.opened) {
 284                                 /*
 285                                  * Disable mevent callback if the FIFO is full.
 286                                  */
 287                                 error = mevent_disable(sc->mev);
 288                                 assert(error == 0);
 289                         }
 290 #ifndef __FreeBSD__
 291                         if (sc->sock && sc->usc_sock.clifd != -1) {
 292                                 /*
 293                                  * Disable mevent callback if the FIFO is full.
 294                                  */
 295                                 error = mevent_disable(sc->mev);
 296                                 assert(error == 0);
 297                         }
 298 #endif /* __FreeBSD__ */
 299                 }
 300                 return (0);
 301         } else
 302                 return (-1);
 303 }
 304
 305 static int
 306 rxfifo_getchar(struct uart_softc *sc)
 307 {
 308         struct fifo *fifo;
 309         int c, error, wasfull;
 310
 311         wasfull = 0;
 312         fifo = &sc->rxfifo;
 313         if (fifo->num > 0) {
 314                 if (!rxfifo_available(sc))
 315                         wasfull = 1;
 316                 c = fifo->buf[fifo->rindex];
 317                 fifo->rindex = (fifo->rindex + 1) % fifo->size;
 318                 fifo->num--;
 319                 if (wasfull) {
 320                         if (sc->tty.opened) {
 321                                 error = mevent_enable(sc->mev);
 322                                 assert(error == 0);
 323                         }
 324 #ifndef __FreeBSD__
 325                         if (sc->sock && sc->usc_sock.clifd != -1) {
 326                                 error = mevent_enable(sc->mev);
 327                                 assert(error == 0);
 328                         }
 329 #endif /* __FreeBSD__ */
 330                 }
 331                 return (c);
 332         } else
 333                 return (-1);
 334 }
 335
 336 static int
 337 rxfifo_numchars(struct uart_softc *sc)
 338 {
 339         struct fifo *fifo = &sc->rxfifo;
 340
 341         return (fifo->num);
 342 }
 343
 344 static void
 345 uart_opentty(struct uart_softc *sc)
 346 {
 347
 348         ttyopen(&sc->tty);
 349         sc->mev = mevent_add(sc->tty.rfd, EVF_READ, uart_drain, sc);
 350         assert(sc->mev != NULL);
 351 }
 352
 353 static uint8_t
 354 modem_status(uint8_t mcr)
 355 {
 356         uint8_t msr;
 357
 358         if (mcr & MCR_LOOPBACK) {
 359                 /*
 360                  * In the loopback mode certain bits from the MCR are
 361                  * reflected back into MSR.
 362                  */
 363                 msr = 0;
 364                 if (mcr & MCR_RTS)
 365                         msr |= MSR_CTS;
 366                 if (mcr & MCR_DTR)
 367                         msr |= MSR_DSR;
 368                 if (mcr & MCR_OUT1)
 369                         msr |= MSR_RI;
 370                 if (mcr & MCR_OUT2)
 371                         msr |= MSR_DCD;
 372         } else {
 373                 /*
 374                  * Always assert DCD and DSR so tty open doesn't block
 375                  * even if CLOCAL is turned off.
 376                  */
 377                 msr = MSR_DCD | MSR_DSR;
 378         }
 379         assert((msr & MSR_DELTA_MASK) == 0);
 380
 381         return (msr);
 382 }
 383
 384 /*
 385  * The IIR returns a prioritized interrupt reason:
 386  * - receive data available
 387  * - transmit holding register empty
 388  * - modem status change
 389  *
 390  * Return an interrupt reason if one is available.
 391  */
 392 static int
 393 uart_intr_reason(struct uart_softc *sc)
 394 {
 395
 396         if ((sc->lsr & LSR_OE) != 0 && (sc->ier & IER_ERLS) != 0)
 397                 return (IIR_RLS);
 398         else if (rxfifo_numchars(sc) > 0 && (sc->ier & IER_ERXRDY) != 0)
 399                 return (IIR_RXTOUT);
 400         else if (sc->thre_int_pending && (sc->ier & IER_ETXRDY) != 0)
 401                 return (IIR_TXRDY);
 402         else if ((sc->msr & MSR_DELTA_MASK) != 0 && (sc->ier & IER_EMSC) != 0)
 403                 return (IIR_MLSC);
 404         else
 405                 return (IIR_NOPEND);
 406 }
 407
 408 static void
 409 uart_reset(struct uart_softc *sc)
 410 {
 411         uint16_t divisor;
 412
 413         divisor = DEFAULT_RCLK / DEFAULT_BAUD / 16;
 414         sc->dll = divisor;
 415 #ifndef __FreeBSD__
 416         sc->dlh = 0;
 417 #else
 418         sc->dlh = divisor >> 16;
 419 #endif
 420         sc->msr = modem_status(sc->mcr);
 421
 422         rxfifo_reset(sc, 1);    /* no fifo until enabled by software */
 423 }
 424
 425 /*
 426  * Toggle the COM port's intr pin depending on whether or not we have an
 427  * interrupt condition to report to the processor.
 428  */
 429 static void
 430 uart_toggle_intr(struct uart_softc *sc)
 431 {
 432         uint8_t intr_reason;
 433
 434         intr_reason = uart_intr_reason(sc);
 435
 436         if (intr_reason == IIR_NOPEND)
 437                 (*sc->intr_deassert)(sc->arg);
 438         else
 439                 (*sc->intr_assert)(sc->arg);
 440 }
 441
 442 static void
 443 uart_drain(int fd, enum ev_type ev, void *arg)
 444 {
 445         struct uart_softc *sc;
 446         int ch;
 447
 448         sc = arg;
 449
 450         assert(fd == sc->tty.rfd);
 451         assert(ev == EVF_READ);
 452
 453         /*
 454          * This routine is called in the context of the mevent thread
 455          * to take out the softc lock to protect against concurrent
 456          * access from a vCPU i/o exit
 457          */
 458         pthread_mutex_lock(&sc->mtx);
 459
 460         if ((sc->mcr & MCR_LOOPBACK) != 0) {
 461                 (void) ttyread(&sc->tty);
 462         } else {
 463                 while (rxfifo_available(sc) &&
 464                        ((ch = ttyread(&sc->tty)) != -1)) {
 465                         rxfifo_putchar(sc, ch);
 466                 }
 467                 uart_toggle_intr(sc);
 468         }
 469
 470         pthread_mutex_unlock(&sc->mtx);
 471 }
 472
 473 void
 474 uart_write(struct uart_softc *sc, int offset, uint8_t value)
 475 {
 476         int fifosz;
 477         uint8_t msr;
 478
 479         pthread_mutex_lock(&sc->mtx);
 480
 481         /*
 482          * Take care of the special case DLAB accesses first
 483          */
 484         if ((sc->lcr & LCR_DLAB) != 0) {
 485                 if (offset == REG_DLL) {
 486                         sc->dll = value;
 487                         goto done;
 488                 }
 489
 490                 if (offset == REG_DLH) {
 491                         sc->dlh = value;
 492                         goto done;
 493                 }
 494         }
 495
 496         switch (offset) {
 497         case REG_DATA:
 498                 if (sc->mcr & MCR_LOOPBACK) {
 499                         if (rxfifo_putchar(sc, value) != 0)
 500                                 sc->lsr |= LSR_OE;
 501                 } else if (sc->tty.opened) {
 502                         ttywrite(&sc->tty, value);
 503 #ifndef __FreeBSD__
 504                 } else if (sc->sock) {
 505                         sockwrite(sc, value);
 506 #endif
 507                 } /* else drop on floor */
 508                 sc->thre_int_pending = true;
 509                 break;
 510         case REG_IER:
 511                 /* Set pending when IER_ETXRDY is raised (edge-triggered). */
 512                 if ((sc->ier & IER_ETXRDY) == 0 && (value & IER_ETXRDY) != 0)
 513                         sc->thre_int_pending = true;
 514                 /*
 515                  * Apply mask so that bits 4-7 are 0
 516                  * Also enables bits 0-3 only if they're 1
 517                  */
 518                 sc->ier = value & 0x0F;
 519                 break;
 520         case REG_FCR:
 521                 /*
 522                  * When moving from FIFO and 16450 mode and vice versa,
 523                  * the FIFO contents are reset.
 524                  */
 525                 if ((sc->fcr & FCR_ENABLE) ^ (value & FCR_ENABLE)) {
 526                         fifosz = (value & FCR_ENABLE) ? FIFOSZ : 1;
 527                         rxfifo_reset(sc, fifosz);
 528                 }
 529
 530                 /*
 531                  * The FCR_ENABLE bit must be '1' for the programming
 532                  * of other FCR bits to be effective.
 533                  */
 534                 if ((value & FCR_ENABLE) == 0) {
 535                         sc->fcr = 0;
 536                 } else {
 537                         if ((value & FCR_RCV_RST) != 0)
 538                                 rxfifo_reset(sc, FIFOSZ);
 539
 540                         sc->fcr = value &
 541                                  (FCR_ENABLE | FCR_DMA | FCR_RX_MASK);
 542                 }
 543                 break;
 544         case REG_LCR:
 545                 sc->lcr = value;
 546                 break;
 547         case REG_MCR:
 548                 /* Apply mask so that bits 5-7 are 0 */
 549                 sc->mcr = value & 0x1F;
 550                 msr = modem_status(sc->mcr);
 551
 552                 /*
 553                  * Detect if there has been any change between the
 554                  * previous and the new value of MSR. If there is
 555                  * then assert the appropriate MSR delta bit.
 556                  */
 557                 if ((msr & MSR_CTS) ^ (sc->msr & MSR_CTS))
 558                         sc->msr |= MSR_DCTS;
 559                 if ((msr & MSR_DSR) ^ (sc->msr & MSR_DSR))
 560                         sc->msr |= MSR_DDSR;
 561                 if ((msr & MSR_DCD) ^ (sc->msr & MSR_DCD))
 562                         sc->msr |= MSR_DDCD;
 563                 if ((sc->msr & MSR_RI) != 0 && (msr & MSR_RI) == 0)
 564                         sc->msr |= MSR_TERI;
 565
 566                 /*
 567                  * Update the value of MSR while retaining the delta
 568                  * bits.
 569                  */
 570                 sc->msr &= MSR_DELTA_MASK;
 571                 sc->msr |= msr;
 572                 break;
 573         case REG_LSR:
 574                 /*
 575                  * Line status register is not meant to be written to
 576                  * during normal operation.
 577                  */
 578                 break;
 579         case REG_MSR:
 580                 /*
 581                  * As far as I can tell MSR is a read-only register.
 582                  */
 583                 break;
 584         case REG_SCR:
 585                 sc->scr = value;
 586                 break;
 587         default:
 588                 break;
 589         }
 590
 591 done:
 592         uart_toggle_intr(sc);
 593         pthread_mutex_unlock(&sc->mtx);
 594 }
 595
 596 uint8_t
 597 uart_read(struct uart_softc *sc, int offset)
 598 {
 599         uint8_t iir, intr_reason, reg;
 600
 601         pthread_mutex_lock(&sc->mtx);
 602
 603         /*
 604          * Take care of the special case DLAB accesses first
 605          */
 606         if ((sc->lcr & LCR_DLAB) != 0) {
 607                 if (offset == REG_DLL) {
 608                         reg = sc->dll;
 609                         goto done;
 610                 }
 611
 612                 if (offset == REG_DLH) {
 613                         reg = sc->dlh;
 614                         goto done;
 615                 }
 616         }
 617
 618         switch (offset) {
 619         case REG_DATA:
 620                 reg = rxfifo_getchar(sc);
 621                 break;
 622         case REG_IER:
 623                 reg = sc->ier;
 624                 break;
 625         case REG_IIR:
 626                 iir = (sc->fcr & FCR_ENABLE) ? IIR_FIFO_MASK : 0;
 627
 628                 intr_reason = uart_intr_reason(sc);
 629
 630                 /*
 631                  * Deal with side effects of reading the IIR register
 632                  */
 633                 if (intr_reason == IIR_TXRDY)
 634                         sc->thre_int_pending = false;
 635
 636                 iir |= intr_reason;
 637
 638                 reg = iir;
 639                 break;
 640         case REG_LCR:
 641                 reg = sc->lcr;
 642                 break;
 643         case REG_MCR:
 644                 reg = sc->mcr;
 645                 break;
 646         case REG_LSR:
 647                 /* Transmitter is always ready for more data */
 648                 sc->lsr |= LSR_TEMT | LSR_THRE;
 649
 650                 /* Check for new receive data */
 651                 if (rxfifo_numchars(sc) > 0)
 652                         sc->lsr |= LSR_RXRDY;
 653                 else
 654                         sc->lsr &= ~LSR_RXRDY;
 655
 656                 reg = sc->lsr;
 657
 658                 /* The LSR_OE bit is cleared on LSR read */
 659                 sc->lsr &= ~LSR_OE;
 660                 break;
 661         case REG_MSR:
 662                 /*
 663                  * MSR delta bits are cleared on read
 664                  */
 665                 reg = sc->msr;
 666                 sc->msr &= ~MSR_DELTA_MASK;
 667                 break;
 668         case REG_SCR:
 669                 reg = sc->scr;
 670                 break;
 671         default:
 672                 reg = 0xFF;
 673                 break;
 674         }
 675
 676 done:
 677         uart_toggle_intr(sc);
 678         pthread_mutex_unlock(&sc->mtx);
 679
 680         return (reg);
 681 }
 682
 683 #ifndef __FreeBSD__
 684 static void
 685 uart_sock_drain(int fd, enum ev_type ev, void *arg)
 686 {
 687         struct uart_softc *sc = arg;
 688         char ch;
 689
 690         /*
 691          * Take the softc lock to protect against concurrent
 692          * access from a vCPU i/o exit
 693          */
 694         pthread_mutex_lock(&sc->mtx);
 695
 696         if ((sc->mcr & MCR_LOOPBACK) != 0) {
 697                 (void) read(sc->usc_sock.clifd, &ch, 1);
 698         } else {
 699                 bool err_close = false;
 700
 701                 while (rxfifo_available(sc)) {
 702                         int res;
 703
 704                         res = read(sc->usc_sock.clifd, &ch, 1);
 705                         if (res == 0) {
 706                                 err_close = true;
 707                                 break;
 708                         } else if (res == -1) {
 709                                 if (errno != EAGAIN && errno != EINTR) {
 710                                         err_close = true;
 711                                 }
 712                                 break;
 713                         }
 714
 715                         rxfifo_putchar(sc, ch);
 716                 }
 717                 uart_toggle_intr(sc);
 718
 719                 if (err_close) {
 720                         (void) fprintf(stderr, "uart: closing client conn\n");
 721                         (void) shutdown(sc->usc_sock.clifd, SHUT_RDWR);
 722                         mevent_delete_close(sc->mev);
 723                         sc->mev = NULL;
 724                         sc->usc_sock.clifd = -1;
 725                 }
 726         }
 727
 728         pthread_mutex_unlock(&sc->mtx);
 729 }
 730
 731 static void
 732 uart_sock_accept(int fd, enum ev_type ev, void *arg)
 733 {
 734         struct uart_softc *sc = arg;
 735         int connfd;
 736
 737         connfd = accept(sc->usc_sock.servfd, NULL, NULL);
 738         if (connfd == -1) {
 739                 return;
 740         }
 741
 742         /*
 743          * Do client connection management under protection of the softc lock
 744          * to avoid racing with concurrent UART events.
 745          */
 746         pthread_mutex_lock(&sc->mtx);
 747
 748         if (sc->usc_sock.clifd != -1) {
 749                 /* we're already handling a client */
 750                 (void) fprintf(stderr, "uart: unexpected client conn\n");
 751                 (void) shutdown(connfd, SHUT_RDWR);
 752                 (void) close(connfd);
 753         } else {
 754                 if (fcntl(connfd, F_SETFL, O_NONBLOCK) < 0) {
 755                         perror("uart: fcntl(O_NONBLOCK)");
 756                         (void) shutdown(connfd, SHUT_RDWR);
 757                         (void) close(connfd);
 758                 } else {
 759                         sc->usc_sock.clifd = connfd;
 760                         sc->mev = mevent_add(sc->usc_sock.clifd, EVF_READ,
 761                             uart_sock_drain, sc);
 762                 }
 763         }
 764
 765         pthread_mutex_unlock(&sc->mtx);
 766 }
 767
 768 static int
 769 init_sock(const char *path)
 770 {
 771         int servfd;
 772         struct sockaddr_un servaddr;
 773
 774         bzero(&servaddr, sizeof (servaddr));
 775         servaddr.sun_family = AF_UNIX;
 776
 777         if (strlcpy(servaddr.sun_path, path, sizeof (servaddr.sun_path)) >=
 778             sizeof (servaddr.sun_path)) {
 779                 (void) fprintf(stderr, "uart: path '%s' too long\n",
 780                     path);
 781                 return (-1);
 782         }
 783
 784         if ((servfd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
 785                 (void) fprintf(stderr, "uart: socket() error - %s\n",
 786                     strerror(errno));
 787                 return (-1);
 788         }
 789         (void) unlink(servaddr.sun_path);
 790
 791         if (bind(servfd, (struct sockaddr *)&servaddr,
 792             sizeof (servaddr)) == -1) {
 793                 (void) fprintf(stderr, "uart: bind() error - %s\n",
 794                     strerror(errno));
 795                 goto out;
 796         }
 797
 798         if (listen(servfd, 1) == -1) {
 799                 (void) fprintf(stderr, "uart: listen() error - %s\n",
 800                     strerror(errno));
 801                 goto out;
 802         }
 803         return (servfd);
 804
 805 out:
 806         (void) unlink(servaddr.sun_path);
 807         (void) close(servfd);
 808         return (-1);
 809 }
 810 #endif /* not __FreeBSD__ */
 811
 812 int
 813 uart_legacy_alloc(int which, int *baseaddr, int *irq)
 814 {
 815
 816         if (which < 0 || which >= (int)UART_NLDEVS || uart_lres[which].inuse)
 817                 return (-1);
 818
 819         uart_lres[which].inuse = true;
 820         *baseaddr = uart_lres[which].baseaddr;
 821         *irq = uart_lres[which].irq;
 822
 823         return (0);
 824 }
 825
 826 struct uart_softc *
 827 uart_init(uart_intr_func_t intr_assert, uart_intr_func_t intr_deassert,
 828     void *arg)
 829 {
 830         struct uart_softc *sc;
 831
 832         sc = calloc(1, sizeof(struct uart_softc));
 833
 834         sc->arg = arg;
 835         sc->intr_assert = intr_assert;
 836         sc->intr_deassert = intr_deassert;
 837
 838         pthread_mutex_init(&sc->mtx, NULL);
 839
 840         uart_reset(sc);
 841
 842         return (sc);
 843 }
 844
 845 #ifndef __FreeBSD__
 846 static int
 847 uart_sock_backend(struct uart_softc *sc, const char *inopts)
 848 {
 849         char *opts, *tofree;
 850         char *opt;
 851         char *nextopt;
 852         char *path = NULL;
 853
 854         if (strncmp(inopts, "socket,", 7) != 0) {
 855                 return (-1);
 856         }
 857         if ((opts = strdup(inopts + 7)) == NULL) {
 858                 return (-1);
 859         }
 860
 861         tofree = nextopt = opts;
 862         for (opt = strsep(&nextopt, ","); opt != NULL;
 863             opt = strsep(&nextopt, ",")) {
 864                 if (path == NULL && *opt == '/') {
 865                         path = opt;
 866                         continue;
 867                 }
 868                 /*
 869                  * XXX check for server and client options here.  For now,
 870                  * everything is a server
 871                  */
 872                 free(tofree);
 873                 return (-1);
 874         }
 875
 876         sc->usc_sock.clifd = -1;
 877         if ((sc->usc_sock.servfd = init_sock(path)) == -1) {
 878                 free(tofree);
 879                 return (-1);
 880         }
 881         sc->sock = true;
 882         sc->tty.rfd = sc->tty.wfd = -1;
 883         sc->usc_sock.servmev = mevent_add(sc->usc_sock.servfd, EVF_READ,
 884             uart_sock_accept, sc);
 885         assert(sc->usc_sock.servmev != NULL);
 886
 887         free(tofree);
 888         return (0);
 889 }
 890 #endif /* not __FreeBSD__ */
 891
 892 static int
 893 uart_stdio_backend(struct uart_softc *sc)
 894 {
 895 #ifndef WITHOUT_CAPSICUM
 896         cap_rights_t rights;
 897         cap_ioctl_t cmds[] = { TIOCGETA, TIOCSETA, TIOCGWINSZ };
 898 #endif
 899
 900         if (uart_stdio)
 901                 return (-1);
 902
 903         sc->tty.rfd = STDIN_FILENO;
 904         sc->tty.wfd = STDOUT_FILENO;
 905         sc->tty.opened = true;
 906
 907         if (fcntl(sc->tty.rfd, F_SETFL, O_NONBLOCK) != 0)
 908                 return (-1);
 909         if (fcntl(sc->tty.wfd, F_SETFL, O_NONBLOCK) != 0)
 910                 return (-1);
 911
 912 #ifndef WITHOUT_CAPSICUM
 913         cap_rights_init(&rights, CAP_EVENT, CAP_IOCTL, CAP_READ);
 914         if (caph_rights_limit(sc->tty.rfd, &rights) == -1)
 915                 errx(EX_OSERR, "Unable to apply rights for sandbox");
 916         if (caph_ioctls_limit(sc->tty.rfd, cmds, nitems(cmds)) == -1)
 917                 errx(EX_OSERR, "Unable to apply rights for sandbox");
 918 #endif
 919
 920         uart_stdio = true;
 921
 922         return (0);
 923 }
 924
 925 static int
 926 uart_tty_backend(struct uart_softc *sc, const char *path)
 927 {
 928 #ifndef WITHOUT_CAPSICUM
 929         cap_rights_t rights;
 930         cap_ioctl_t cmds[] = { TIOCGETA, TIOCSETA, TIOCGWINSZ };
 931 #endif
 932         int fd;
 933
 934         fd = open(path, O_RDWR | O_NONBLOCK);
 935         if (fd < 0)
 936                 return (-1);
 937
 938         if (!isatty(fd)) {
 939                 close(fd);
 940                 return (-1);
 941         }
 942
 943         sc->tty.rfd = sc->tty.wfd = fd;
 944         sc->tty.opened = true;
 945
 946 #ifndef WITHOUT_CAPSICUM
 947         cap_rights_init(&rights, CAP_EVENT, CAP_IOCTL, CAP_READ, CAP_WRITE);
 948         if (caph_rights_limit(fd, &rights) == -1)
 949                 errx(EX_OSERR, "Unable to apply rights for sandbox");
 950         if (caph_ioctls_limit(fd, cmds, nitems(cmds)) == -1)
 951                 errx(EX_OSERR, "Unable to apply rights for sandbox");
 952 #endif
 953
 954         return (0);
 955 }
 956
 957 int
 958 uart_set_backend(struct uart_softc *sc, const char *device)
 959 {
 960         int retval;
 961
 962         if (device == NULL)
 963                 return (0);
 964
 965 #ifndef __FreeBSD__
 966         if (strncmp("socket,", device, 7) == 0)
 967                 return (uart_sock_backend(sc, device));
 968 #endif
 969         if (strcmp("stdio", device) == 0)
 970                 retval = uart_stdio_backend(sc);
 971         else
 972                 retval = uart_tty_backend(sc, device);
 973         if (retval == 0)
 974                 uart_opentty(sc);
 975
 976         return (retval);
 977 }