freebsd.c

   1 /*
   2  * This file is part of the libserialport project.
   3  *
   4  * Copyright (C) 2015 Uffe Jakobsen <uffe@uffe.org>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU Lesser General Public License as
   8  * published by the Free Software Foundation, either version 3 of the
   9  * License, or (at your option) any later version.
  10  *
  11  * This program 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
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * FreeBSD platform specific serial port information:
  22  *
  23  * FreeBSD has two device nodes for each serial port:
  24  *
  25  *  1) a call-in port
  26  *  2) a call-out port
  27  *
  28  * Quoting FreeBSD Handbook section 26.2.1
  29  * (https://www.freebsd.org/doc/handbook/serial.html)
  30  *
  31  * In FreeBSD, each serial port is accessed through an entry in /dev.
  32  * There are two different kinds of entries:
  33  *
  34  * 1) Call-in ports are named /dev/ttyuN where N is the port number,
  35  *    starting from zero. If a terminal is connected to the first serial port
  36  *    (COM1), use /dev/ttyu0 to refer to the terminal. If the terminal is on
  37  *    the second serial port (COM2), use /dev/ttyu1, and so forth.
  38  *    Generally, the call-in port is used for terminals. Call-in ports require
  39  *    that the serial line assert the "Data Carrier Detect" signal to work
  40  *    correctly.
  41  *
  42  * 2) Call-out ports are named /dev/cuauN on FreeBSD versions 10.x and higher
  43  *    and /dev/cuadN on FreeBSD versions 9.x and lower. Call-out ports are
  44  *    usually not used for terminals, but are used for modems. The call-out
  45  *    port can be used if the serial cable or the terminal does not support
  46  *    the "Data Carrier Detect" signal.
  47  *
  48  * FreeBSD also provides initialization devices (/dev/ttyuN.init and
  49  * /dev/cuauN.init or /dev/cuadN.init) and locking devices (/dev/ttyuN.lock
  50  * and /dev/cuauN.lock or /dev/cuadN.lock). The initialization devices are
  51  * used to initialize communications port parameters each time a port is
  52  * opened, such as crtscts for modems which use RTS/CTS signaling for flow
  53  * control. The locking devices are used to lock flags on ports to prevent
  54  * users or programs changing certain parameters.
  55  *
  56  * In line with the above device naming USB-serial devices have
  57  * the following naming:
  58  *
  59  * 1) call-in ports: /dev/ttyUN where N is the port number
  60  * 2) call-out ports: /dev/cuaUN where N is the port number
  61  *
  62  * See also: ucom(4), https://www.freebsd.org/cgi/man.cgi?query=ucom
  63  *
  64  * Getting USB serial port device description:
  65  *
  66  * In order to query USB serial ports for device description - the mapping
  67  * between the kernel device driver instances must be correlated with the
  68  * above mentioned device nodes.
  69  *
  70  * 1) For each USB-serial port (/dev/cuaUN) use libusb to lookup the device
  71  *    description and the name of the kernel device driver instance.
  72  * 2) Query sysctl for the kernel device driver instance info.
  73  * 3) Derive the ttyname and (serial) port count for the kernel device
  74  *    driver instance.
  75  * 4) If sysctl ttyname and port matches /dev/cuaUN apply the libusb
  76  *    device description.
  77  */
  78
  79 #include <unistd.h>
  80 #include <stdint.h>
  81 #include <stdlib.h>
  82 #include <limits.h>
  83 #include <stdio.h>
  84 #include <string.h>
  85 #include <sys/types.h>
  86 #include <sys/sysctl.h>
  87 #include <dirent.h>
  88 #include <libusb20.h>
  89 #include <libusb20_desc.h>
  90 #include "libserialport.h"
  91 #include "libserialport_internal.h"
  92
  93 #define DEV_CUA_PATH "/dev/cua"
  94
  95 //#define DBG(...) printf(__VA_ARGS__)
  96 #define DBG(...)
  97
  98 static char *strrspn(const char *s, const char *charset)
  99 {
 100         char *t = (char *)s + strlen(s);
 101         while (t != (char *)s)
 102                 if (!strchr(charset, *(--t)))
 103                         return ++t;
 104         return t;
 105 }
 106
 107 static int strend(const char *str, const char *pattern)
 108 {
 109         size_t slen = strlen(str);
 110         size_t plen = strlen(pattern);
 111         if (slen >= plen)
 112                 return (!memcmp(pattern, (str + slen - plen), plen));
 113         return 0;
 114 }
 115
 116 static int libusb_query_port(struct libusb20_device *dev, int idx,
 117                              char **drv_name_str, char **drv_inst_str)
 118 {
 119         int rc;
 120         char *j;
 121         char sbuf[FILENAME_MAX];
 122
 123         if (!drv_name_str || !drv_inst_str)
 124                 return -1;
 125
 126         rc = libusb20_dev_kernel_driver_active(dev, idx);
 127         if (rc < 0)
 128                 return rc;
 129
 130         sbuf[0] = 0;
 131         libusb20_dev_get_iface_desc(dev, idx, (char *)&sbuf,
 132                                     (uint8_t)sizeof(sbuf) - 1);
 133         if (sbuf[0] == 0)
 134                 return rc;
 135
 136         DBG("device interface descriptor: idx=%003d '%s'\n", idx, sbuf);
 137         j = strchr(sbuf, ':');
 138         if (j > sbuf) {
 139                 sbuf[j - sbuf] = 0;
 140                 /*
 141                  * The device driver name may contain digits that
 142                  * is not a part of the device instance number - like "u3g".
 143                  */
 144                 j = strrspn(sbuf, "0123456789");
 145                 if (j > sbuf) {
 146                         *drv_name_str = strndup(sbuf, j - sbuf);
 147                         *drv_inst_str = strdup((j));
 148                 }
 149         }
 150
 151         return rc;
 152 }
 153
 154 static int sysctl_query_dev_drv(const char *drv_name_str,
 155         const char *drv_inst_str, char **ttyname, int *const ttyport_cnt)
 156 {
 157         int rc;
 158         char sbuf[FILENAME_MAX];
 159         char tbuf[FILENAME_MAX];
 160         size_t tbuf_len;
 161
 162         if (!ttyname || !ttyport_cnt)
 163                 return -1;
 164
 165         snprintf(sbuf, sizeof(sbuf), "dev.%s.%s.ttyname", drv_name_str,
 166                  drv_inst_str);
 167         tbuf_len = sizeof(tbuf) - 1;
 168         if ((rc = sysctlbyname(sbuf, tbuf, &tbuf_len, NULL, 0)) != 0)
 169                 return rc;
 170
 171         tbuf[tbuf_len] = 0;
 172         *ttyname = strndup(tbuf, tbuf_len);
 173         DBG("sysctl: '%s' (%d) (%d): '%.*s'\n", sbuf, rc, (int)tbuf_len,
 174             (int)tbuf_len, tbuf);
 175
 176         snprintf(sbuf, sizeof(sbuf), "dev.%s.%s.ttyports",
 177                  drv_name_str, drv_inst_str);
 178         tbuf_len = sizeof(tbuf) - 1;
 179         rc = sysctlbyname(sbuf, tbuf, &tbuf_len, NULL, 0);
 180         if (rc == 0) {
 181                 *ttyport_cnt = *(uint32_t *)tbuf;
 182                 DBG("sysctl: '%s' (%d) (%d): '%d'\n", sbuf, rc,
 183                     (int)tbuf_len, (int)ttyport_cnt);
 184         } else {
 185                 *ttyport_cnt = 0;
 186         }
 187
 188         return rc;
 189 }
 190
 191 static int populate_port_struct_from_libusb_desc(struct sp_port *const port,
 192                                                  struct libusb20_device *dev)
 193 {
 194         char tbuf[FILENAME_MAX];
 195
 196         /* Populate port structure from libusb description. */
 197         struct LIBUSB20_DEVICE_DESC_DECODED *dev_desc =
 198                 libusb20_dev_get_device_desc(dev);
 199
 200         if (!dev_desc)
 201                 return -1;
 202
 203         port->transport = SP_TRANSPORT_USB;
 204         port->usb_vid = dev_desc->idVendor;
 205         port->usb_pid = dev_desc->idProduct;
 206         port->usb_bus = libusb20_dev_get_bus_number(dev);
 207         port->usb_address = libusb20_dev_get_address(dev);
 208         if (libusb20_dev_req_string_simple_sync
 209             (dev, dev_desc->iManufacturer, tbuf, sizeof(tbuf)) == 0) {
 210                 port->usb_manufacturer = strdup(tbuf);
 211         }
 212         if (libusb20_dev_req_string_simple_sync
 213             (dev, dev_desc->iProduct, tbuf, sizeof(tbuf)) == 0) {
 214                 port->usb_product = strdup(tbuf);
 215         }
 216         if (libusb20_dev_req_string_simple_sync
 217             (dev, dev_desc->iSerialNumber, tbuf, sizeof(tbuf)) == 0) {
 218                 port->usb_serial = strdup(tbuf);
 219         }
 220         /* If present, add serial to description for better identification. */
 221         tbuf[0] = '\0';
 222         if (port->usb_product && port->usb_product[0])
 223                 strncat(tbuf, port->usb_product, sizeof(tbuf) - 1);
 224         else
 225                 strncat(tbuf, libusb20_dev_get_desc(dev), sizeof(tbuf) - 1);
 226         if (port->usb_serial && port->usb_serial[0]) {
 227                 strncat(tbuf, " ", sizeof(tbuf) - 1);
 228                 strncat(tbuf, port->usb_serial, sizeof(tbuf) - 1);
 229         }
 230         port->description = strdup(tbuf);
 231         port->bluetooth_address = NULL;
 232
 233         return 0;
 234 }
 235
 236 SP_PRIV enum sp_return get_port_details(struct sp_port *port)
 237 {
 238         int rc;
 239         struct libusb20_backend *be;
 240         struct libusb20_device *dev, *dev_last;
 241         char tbuf[FILENAME_MAX];
 242         char *cua_sfx;
 243         int cua_dev_found;
 244         uint8_t idx;
 245         int sub_inst;
 246
 247         DBG("portname: '%s'\n", port->name);
 248
 249         if (!strncmp(port->name, DEV_CUA_PATH, strlen(DEV_CUA_PATH))) {
 250                 cua_sfx = port->name + strlen(DEV_CUA_PATH);
 251                 DBG("'%s': '%s'\n", DEV_CUA_PATH, cua_sfx);
 252         } else {
 253                 RETURN_ERROR(SP_ERR_ARG, "Device name not recognized.");
 254         }
 255
 256         /* Native UART enumeration. */
 257         if ((cua_sfx[0] == 'u') || (cua_sfx[0] == 'd')) {
 258                 port->transport = SP_TRANSPORT_NATIVE;
 259                 snprintf(tbuf, sizeof(tbuf), "cua%s", cua_sfx);
 260                 port->description = strdup(tbuf);
 261                 RETURN_OK();
 262         }
 263
 264         /* USB device enumeration. */
 265         dev = dev_last = NULL;
 266         be = libusb20_be_alloc_default();
 267         cua_dev_found = 0;
 268         while (cua_dev_found == 0) {
 269                 dev = libusb20_be_device_foreach(be, dev_last);
 270                 if (!dev)
 271                         break;
 272
 273                 libusb20_dev_open(dev, 0);
 274                 DBG("device descriptor: '%s'\n", libusb20_dev_get_desc(dev));
 275
 276                 for (idx = 0; idx <= UINT8_MAX - 1; idx++) {
 277                         char *drv_name_str = NULL;
 278                         char *drv_inst_str = NULL;
 279                         char *ttyname = NULL;
 280                         int ttyport_cnt;
 281
 282                         rc = libusb_query_port(dev, idx, &drv_name_str, &drv_inst_str);
 283                         if (rc == 0) {
 284                                 rc = sysctl_query_dev_drv(drv_name_str,
 285                                           drv_inst_str, &ttyname, &ttyport_cnt);
 286                                 if (rc == 0) {
 287                                         /* Handle multiple subinstances of serial ports in the same driver instance. */
 288                                         for (sub_inst = 0; sub_inst < ttyport_cnt; sub_inst++) {
 289                                                 if (ttyport_cnt == 1)
 290                                                         snprintf(tbuf, sizeof(tbuf), "%s", ttyname);
 291                                                 else
 292                                                         snprintf(tbuf, sizeof(tbuf), "%s.%d", ttyname, sub_inst);
 293                                                 if (!strcmp(cua_sfx, tbuf)) {
 294                                                         DBG("MATCH: '%s' == '%s'\n", cua_sfx, tbuf);
 295                                                         cua_dev_found = 1;
 296                                                         populate_port_struct_from_libusb_desc(port, dev);
 297                                                         break; /* Break out of sub instance loop. */
 298                                                 }
 299                                         }
 300                                 }
 301                         }
 302
 303                         /* Clean up. */
 304                         if (ttyname)
 305                                 free(ttyname);
 306                         if (drv_name_str)
 307                                 free(drv_name_str);
 308                         if (drv_inst_str)
 309                                 free(drv_inst_str);
 310                         if (cua_dev_found)
 311                                 break; /* Break out of USB device port idx loop. */
 312                 }
 313                 libusb20_dev_close(dev);
 314                 dev_last = dev;
 315         }
 316         libusb20_be_free(be);
 317
 318         if (cua_dev_found == 0)
 319                 DBG("WARN: found no match '%s' %s'\n", port->name, cua_sfx);
 320
 321         RETURN_OK();
 322 }
 323
 324 SP_PRIV enum sp_return list_ports(struct sp_port ***list)
 325 {
 326         DIR *dir;
 327         struct dirent entry;
 328         struct dirent *result;
 329         struct termios tios;
 330         char name[PATH_MAX];
 331         int fd, ret;
 332
 333         DEBUG("Enumerating tty devices");
 334         if (!(dir = opendir("/dev")))
 335                 RETURN_FAIL("could not open dir /dev");
 336
 337         DEBUG("Iterating over results");
 338         while (!readdir_r(dir, &entry, &result) && result) {
 339                 ret = SP_OK;
 340                 if (entry.d_type != DT_CHR)
 341                         continue;
 342                 if (strncmp(entry.d_name, "cuaU", 4) != 0)
 343                         if (strncmp(entry.d_name, "cuau", 4) != 0)
 344                                 if (strncmp(entry.d_name, "cuad", 4) != 0)
 345                                         continue;
 346                 if (strend(entry.d_name, ".init"))
 347                         continue;
 348                 if (strend(entry.d_name, ".lock"))
 349                         continue;
 350
 351                 snprintf(name, sizeof(name), "/dev/%s", entry.d_name);
 352                 DEBUG_FMT("Found device %s", name);
 353
 354                 /* Check that we can open tty/cua device in rw mode - we need that. */
 355                 if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY | O_TTY_INIT | O_CLOEXEC)) < 0) {
 356                         DEBUG("open failed, skipping");
 357                         continue;
 358                 }
 359
 360                 /* Sanity check if we got a real tty. */
 361                 if (!isatty(fd)) {
 362                         close(fd);
 363                         continue;
 364                 }
 365
 366                 ret = tcgetattr(fd, &tios);
 367                 close(fd);
 368                 if (ret < 0 || cfgetospeed(&tios) <= 0 || cfgetispeed(&tios) <= 0)
 369                         continue;
 370
 371                 DEBUG_FMT("Found port %s", name);
 372                 DBG("%s: %s\n", __func__, entry.d_name);
 373
 374                 *list = list_append(*list, name);
 375                 if (!list) {
 376                         SET_ERROR(ret, SP_ERR_MEM, "list append failed");
 377                         break;
 378                 }
 379         }
 380         closedir(dir);
 381
 382         return ret;
 383 }