libserialport/freebsd.c

384 lines
11 KiB
C

/*
* This file is part of the libserialport project.
*
* Copyright (C) 2015 Uffe Jakobsen <uffe@uffe.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* FreeBSD platform specific serial port information:
*
* FreeBSD has two device nodes for each serial port:
*
* 1) a call-in port
* 2) a call-out port
*
* Quoting FreeBSD Handbook section 26.2.1
* (https://www.freebsd.org/doc/handbook/serial.html)
*
* In FreeBSD, each serial port is accessed through an entry in /dev.
* There are two different kinds of entries:
*
* 1) Call-in ports are named /dev/ttyuN where N is the port number,
* starting from zero. If a terminal is connected to the first serial port
* (COM1), use /dev/ttyu0 to refer to the terminal. If the terminal is on
* the second serial port (COM2), use /dev/ttyu1, and so forth.
* Generally, the call-in port is used for terminals. Call-in ports require
* that the serial line assert the "Data Carrier Detect" signal to work
* correctly.
*
* 2) Call-out ports are named /dev/cuauN on FreeBSD versions 10.x and higher
* and /dev/cuadN on FreeBSD versions 9.x and lower. Call-out ports are
* usually not used for terminals, but are used for modems. The call-out
* port can be used if the serial cable or the terminal does not support
* the "Data Carrier Detect" signal.
*
* FreeBSD also provides initialization devices (/dev/ttyuN.init and
* /dev/cuauN.init or /dev/cuadN.init) and locking devices (/dev/ttyuN.lock
* and /dev/cuauN.lock or /dev/cuadN.lock). The initialization devices are
* used to initialize communications port parameters each time a port is
* opened, such as crtscts for modems which use RTS/CTS signaling for flow
* control. The locking devices are used to lock flags on ports to prevent
* users or programs changing certain parameters.
*
* In line with the above device naming USB-serial devices have
* the following naming:
*
* 1) call-in ports: /dev/ttyUN where N is the port number
* 2) call-out ports: /dev/cuaUN where N is the port number
*
* See also: ucom(4), https://www.freebsd.org/cgi/man.cgi?query=ucom
*
* Getting USB serial port device description:
*
* In order to query USB serial ports for device description - the mapping
* between the kernel device driver instances must be correlated with the
* above mentioned device nodes.
*
* 1) For each USB-serial port (/dev/cuaUN) use libusb to lookup the device
* description and the name of the kernel device driver instance.
* 2) Query sysctl for the kernel device driver instance info.
* 3) Derive the ttyname and (serial) port count for the kernel device
* driver instance.
* 4) If sysctl ttyname and port matches /dev/cuaUN apply the libusb
* device description.
*/
#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/sysctl.h>
#include <dirent.h>
#include <libusb20.h>
#include <libusb20_desc.h>
#include "libserialport.h"
#include "libserialport_internal.h"
#define DEV_CUA_PATH "/dev/cua"
//#define DBG(...) printf(__VA_ARGS__)
#define DBG(...)
static char *strrspn(const char *s, const char *charset)
{
char *t = (char *)s + strlen(s);
while (t != (char *)s)
if (!strchr(charset, *(--t)))
return ++t;
return t;
}
static int strend(const char *str, const char *pattern)
{
size_t slen = strlen(str);
size_t plen = strlen(pattern);
if (slen >= plen)
return (!memcmp(pattern, (str + slen - plen), plen));
return 0;
}
static int libusb_query_port(struct libusb20_device *dev, int idx,
char **drv_name_str, char **drv_inst_str)
{
int rc;
char *j;
char sbuf[FILENAME_MAX];
if (!drv_name_str || !drv_inst_str)
return -1;
rc = libusb20_dev_kernel_driver_active(dev, idx);
if (rc < 0)
return rc;
sbuf[0] = 0;
libusb20_dev_get_iface_desc(dev, idx, (char *)&sbuf,
(uint8_t)sizeof(sbuf) - 1);
if (sbuf[0] == 0)
return rc;
DBG("Device interface descriptor: idx=%003d '%s'\n", idx, sbuf);
j = strchr(sbuf, ':');
if (j > sbuf) {
sbuf[j - sbuf] = 0;
/*
* The device driver name may contain digits that
* is not a part of the device instance number - like "u3g".
*/
j = strrspn(sbuf, "0123456789");
if (j > sbuf) {
*drv_name_str = strndup(sbuf, j - sbuf);
*drv_inst_str = strdup((j));
}
}
return rc;
}
static int sysctl_query_dev_drv(const char *drv_name_str,
const char *drv_inst_str, char **ttyname, int *const ttyport_cnt)
{
int rc;
char sbuf[FILENAME_MAX];
char tbuf[FILENAME_MAX];
size_t tbuf_len;
if (!ttyname || !ttyport_cnt)
return -1;
snprintf(sbuf, sizeof(sbuf), "dev.%s.%s.ttyname", drv_name_str,
drv_inst_str);
tbuf_len = sizeof(tbuf) - 1;
if ((rc = sysctlbyname(sbuf, tbuf, &tbuf_len, NULL, 0)) != 0)
return rc;
tbuf[tbuf_len] = 0;
*ttyname = strndup(tbuf, tbuf_len);
DBG("sysctl: '%s' (%d) (%d): '%.*s'\n", sbuf, rc, (int)tbuf_len,
(int)tbuf_len, tbuf);
snprintf(sbuf, sizeof(sbuf), "dev.%s.%s.ttyports",
drv_name_str, drv_inst_str);
tbuf_len = sizeof(tbuf) - 1;
rc = sysctlbyname(sbuf, tbuf, &tbuf_len, NULL, 0);
if (rc == 0) {
*ttyport_cnt = *(uint32_t *)tbuf;
DBG("sysctl: '%s' (%d) (%d): '%d'\n", sbuf, rc,
(int)tbuf_len, (int)ttyport_cnt);
} else {
*ttyport_cnt = 0;
}
return rc;
}
static int populate_port_struct_from_libusb_desc(struct sp_port *const port,
struct libusb20_device *dev)
{
char tbuf[FILENAME_MAX];
/* Populate port structure from libusb description. */
struct LIBUSB20_DEVICE_DESC_DECODED *dev_desc =
libusb20_dev_get_device_desc(dev);
if (!dev_desc)
return -1;
port->transport = SP_TRANSPORT_USB;
port->usb_vid = dev_desc->idVendor;
port->usb_pid = dev_desc->idProduct;
port->usb_bus = libusb20_dev_get_bus_number(dev);
port->usb_address = libusb20_dev_get_address(dev);
if (libusb20_dev_req_string_simple_sync
(dev, dev_desc->iManufacturer, tbuf, sizeof(tbuf)) == 0) {
port->usb_manufacturer = strdup(tbuf);
}
if (libusb20_dev_req_string_simple_sync
(dev, dev_desc->iProduct, tbuf, sizeof(tbuf)) == 0) {
port->usb_product = strdup(tbuf);
}
if (libusb20_dev_req_string_simple_sync
(dev, dev_desc->iSerialNumber, tbuf, sizeof(tbuf)) == 0) {
port->usb_serial = strdup(tbuf);
}
/* If present, add serial to description for better identification. */
tbuf[0] = '\0';
if (port->usb_product && port->usb_product[0])
strncat(tbuf, port->usb_product, sizeof(tbuf) - 1);
else
strncat(tbuf, libusb20_dev_get_desc(dev), sizeof(tbuf) - 1);
if (port->usb_serial && port->usb_serial[0]) {
strncat(tbuf, " ", sizeof(tbuf) - 1);
strncat(tbuf, port->usb_serial, sizeof(tbuf) - 1);
}
port->description = strdup(tbuf);
port->bluetooth_address = NULL;
return 0;
}
SP_PRIV enum sp_return get_port_details(struct sp_port *port)
{
int rc;
struct libusb20_backend *be;
struct libusb20_device *dev, *dev_last;
char tbuf[FILENAME_MAX];
char *cua_sfx;
int cua_dev_found;
uint8_t idx;
int sub_inst;
DBG("Portname: '%s'\n", port->name);
if (!strncmp(port->name, DEV_CUA_PATH, strlen(DEV_CUA_PATH))) {
cua_sfx = port->name + strlen(DEV_CUA_PATH);
DBG("'%s': '%s'\n", DEV_CUA_PATH, cua_sfx);
} else {
RETURN_ERROR(SP_ERR_ARG, "Device name not recognized");
}
/* Native UART enumeration. */
if ((cua_sfx[0] == 'u') || (cua_sfx[0] == 'd')) {
port->transport = SP_TRANSPORT_NATIVE;
snprintf(tbuf, sizeof(tbuf), "cua%s", cua_sfx);
port->description = strdup(tbuf);
RETURN_OK();
}
/* USB device enumeration. */
dev = dev_last = NULL;
be = libusb20_be_alloc_default();
cua_dev_found = 0;
while (cua_dev_found == 0) {
dev = libusb20_be_device_foreach(be, dev_last);
if (!dev)
break;
libusb20_dev_open(dev, 0);
DBG("Device descriptor: '%s'\n", libusb20_dev_get_desc(dev));
for (idx = 0; idx <= UINT8_MAX - 1; idx++) {
char *drv_name_str = NULL;
char *drv_inst_str = NULL;
char *ttyname = NULL;
int ttyport_cnt;
rc = libusb_query_port(dev, idx, &drv_name_str, &drv_inst_str);
if (rc == 0) {
rc = sysctl_query_dev_drv(drv_name_str,
drv_inst_str, &ttyname, &ttyport_cnt);
if (rc == 0) {
/* Handle multiple subinstances of serial ports in the same driver instance. */
for (sub_inst = 0; sub_inst < ttyport_cnt; sub_inst++) {
if (ttyport_cnt == 1)
snprintf(tbuf, sizeof(tbuf), "%s", ttyname);
else
snprintf(tbuf, sizeof(tbuf), "%s.%d", ttyname, sub_inst);
if (!strcmp(cua_sfx, tbuf)) {
DBG("MATCH: '%s' == '%s'\n", cua_sfx, tbuf);
cua_dev_found = 1;
populate_port_struct_from_libusb_desc(port, dev);
break; /* Break out of sub instance loop. */
}
}
}
}
/* Clean up. */
if (ttyname)
free(ttyname);
if (drv_name_str)
free(drv_name_str);
if (drv_inst_str)
free(drv_inst_str);
if (cua_dev_found)
break; /* Break out of USB device port idx loop. */
}
libusb20_dev_close(dev);
dev_last = dev;
}
libusb20_be_free(be);
if (cua_dev_found == 0)
DBG("WARN: Found no match '%s' %s'\n", port->name, cua_sfx);
RETURN_OK();
}
SP_PRIV enum sp_return list_ports(struct sp_port ***list)
{
DIR *dir;
struct dirent entry;
struct dirent *result;
struct termios tios;
char name[PATH_MAX];
int fd, ret;
DEBUG("Enumerating tty devices");
if (!(dir = opendir("/dev")))
RETURN_FAIL("Could not open dir /dev");
DEBUG("Iterating over results");
while (!readdir_r(dir, &entry, &result) && result) {
ret = SP_OK;
if (entry.d_type != DT_CHR)
continue;
if (strncmp(entry.d_name, "cuaU", 4) != 0)
if (strncmp(entry.d_name, "cuau", 4) != 0)
if (strncmp(entry.d_name, "cuad", 4) != 0)
continue;
if (strend(entry.d_name, ".init"))
continue;
if (strend(entry.d_name, ".lock"))
continue;
snprintf(name, sizeof(name), "/dev/%s", entry.d_name);
DEBUG_FMT("Found device %s", name);
/* Check that we can open tty/cua device in rw mode - we need that. */
if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY | O_TTY_INIT | O_CLOEXEC)) < 0) {
DEBUG("Open failed, skipping");
continue;
}
/* Sanity check if we got a real tty. */
if (!isatty(fd)) {
close(fd);
continue;
}
ret = tcgetattr(fd, &tios);
close(fd);
if (ret < 0 || cfgetospeed(&tios) <= 0 || cfgetispeed(&tios) <= 0)
continue;
DEBUG_FMT("Found port %s", name);
DBG("%s: %s\n", __func__, entry.d_name);
*list = list_append(*list, name);
if (!list) {
SET_ERROR(ret, SP_ERR_MEM, "List append failed");
break;
}
}
closedir(dir);
return ret;
}