linux.c

   1 /*
   2  * This file is part of the libserialport project.
   3  *
   4  * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.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 #include "libserialport.h"
  21 #include "libserialport_internal.h"
  22
  23 SP_PRIV enum sp_return get_port_details(struct sp_port *port)
  24 {
  25         /* Description limited to 127 char,
  26            anything longer would not be user friendly anyway */
  27         char description[128];
  28         int bus, address, vid, pid = -1;
  29         char manufacturer[128], product[128], serial[128];
  30         char baddr[32];
  31         const char dir_name[] = "/sys/class/tty/%s/device/%s%s";
  32         char sub_dir[32] = "", file_name[PATH_MAX];
  33         char *ptr, *dev = port->name + 5;
  34         FILE *file;
  35         int i, count;
  36
  37         if (strncmp(port->name, "/dev/", 5))
  38                 RETURN_ERROR(SP_ERR_ARG, "Device name not recognized (%s)", port->name);
  39
  40         snprintf(file_name, sizeof(file_name), "/sys/class/tty/%s", dev);
  41         count = readlink(file_name, file_name, sizeof(file_name));
  42         if (count <= 0 || count >= (int) sizeof(file_name)-1)
  43                 RETURN_ERROR(SP_ERR_ARG, "Device not found (%s)", port->name);
  44         file_name[count] = 0;
  45         if (strstr(file_name, "bluetooth"))
  46                 port->transport = SP_TRANSPORT_BLUETOOTH;
  47         else if (strstr(file_name, "usb"))
  48                 port->transport = SP_TRANSPORT_USB;
  49
  50         if (port->transport == SP_TRANSPORT_USB) {
  51                 for (i=0; i<5; i++) {
  52                         strcat(sub_dir, "../");
  53
  54                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "busnum");
  55                         if (!(file = fopen(file_name, "r")))
  56                                 continue;
  57                         count = fscanf(file, "%d", &bus);
  58                         fclose(file);
  59                         if (count != 1)
  60                                 continue;
  61
  62                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "devnum");
  63                         if (!(file = fopen(file_name, "r")))
  64                                 continue;
  65                         count = fscanf(file, "%d", &address);
  66                         fclose(file);
  67                         if (count != 1)
  68                                 continue;
  69
  70                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "idVendor");
  71                         if (!(file = fopen(file_name, "r")))
  72                                 continue;
  73                         count = fscanf(file, "%4x", &vid);
  74                         fclose(file);
  75                         if (count != 1)
  76                                 continue;
  77
  78                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "idProduct");
  79                         if (!(file = fopen(file_name, "r")))
  80                                 continue;
  81                         count = fscanf(file, "%4x", &pid);
  82                         fclose(file);
  83                         if (count != 1)
  84                                 continue;
  85
  86                         port->usb_bus = bus;
  87                         port->usb_address = address;
  88                         port->usb_vid = vid;
  89                         port->usb_pid = pid;
  90
  91                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "product");
  92                         if ((file = fopen(file_name, "r"))) {
  93                                 if ((ptr = fgets(description, sizeof(description), file))) {
  94                                         ptr = description + strlen(description) - 1;
  95                                         if (ptr >= description && *ptr == '\n')
  96                                                 *ptr = 0;
  97                                         port->description = strdup(description);
  98                                 }
  99                                 fclose(file);
 100                         }
 101                         if (!file || !ptr)
 102                                 port->description = strdup(dev);
 103
 104                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "manufacturer");
 105                         if ((file = fopen(file_name, "r"))) {
 106                                 if ((ptr = fgets(manufacturer, sizeof(manufacturer), file))) {
 107                                         ptr = manufacturer + strlen(manufacturer) - 1;
 108                                         if (ptr >= manufacturer && *ptr == '\n')
 109                                                 *ptr = 0;
 110                                         port->usb_manufacturer = strdup(manufacturer);
 111                                 }
 112                                 fclose(file);
 113                         }
 114
 115                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "product");
 116                         if ((file = fopen(file_name, "r"))) {
 117                                 if ((ptr = fgets(product, sizeof(product), file))) {
 118                                         ptr = product + strlen(product) - 1;
 119                                         if (ptr >= product && *ptr == '\n')
 120                                                 *ptr = 0;
 121                                         port->usb_product = strdup(product);
 122                                 }
 123                                 fclose(file);
 124                         }
 125
 126                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "serial");
 127                         if ((file = fopen(file_name, "r"))) {
 128                                 if ((ptr = fgets(serial, sizeof(serial), file))) {
 129                                         ptr = serial + strlen(serial) - 1;
 130                                         if (ptr >= serial && *ptr == '\n')
 131                                                 *ptr = 0;
 132                                         port->usb_serial = strdup(serial);
 133                                 }
 134                                 fclose(file);
 135                         }
 136
 137                         break;
 138                 }
 139         } else {
 140                 port->description = strdup(dev);
 141
 142                 if (port->transport == SP_TRANSPORT_BLUETOOTH) {
 143                         snprintf(file_name, sizeof(file_name), dir_name, dev, "", "address");
 144                         if ((file = fopen(file_name, "r"))) {
 145                                 if ((ptr = fgets(baddr, sizeof(baddr), file))) {
 146                                         ptr = baddr + strlen(baddr) - 1;
 147                                         if (ptr >= baddr && *ptr == '\n')
 148                                                 *ptr = 0;
 149                                         port->bluetooth_address = strdup(baddr);
 150                                 }
 151                                 fclose(file);
 152                         }
 153                 }
 154         }
 155
 156         RETURN_OK();
 157 }
 158
 159 SP_PRIV enum sp_return list_ports(struct sp_port ***list)
 160 {
 161         char name[PATH_MAX], target[PATH_MAX];
 162         struct dirent entry, *result;
 163 #ifdef HAVE_SERIAL_STRUCT
 164         struct serial_struct serial_info;
 165         int ioctl_result;
 166 #endif
 167 #ifndef HAVE_READLINKAT
 168         char buf[sizeof(entry.d_name) + 16];
 169 #endif
 170         int len, fd;
 171         DIR *dir;
 172         int ret = SP_OK;
 173
 174         DEBUG("Enumerating tty devices");
 175         if (!(dir = opendir("/sys/class/tty")))
 176                 RETURN_FAIL("could not open /sys/class/tty");
 177
 178         DEBUG("Iterating over results");
 179         while (!readdir_r(dir, &entry, &result) && result) {
 180 #ifdef HAVE_READLINKAT
 181                 len = readlinkat(dirfd(dir), entry.d_name, target, sizeof(target));
 182 #else
 183                 snprintf(buf, sizeof(buf), "/sys/class/tty/%s", entry.d_name);
 184                 len = readlink(buf, target, sizeof(target));
 185 #endif
 186                 if (len <= 0 || len >= (int) sizeof(target)-1)
 187                         continue;
 188                 target[len] = 0;
 189                 if (strstr(target, "virtual"))
 190                         continue;
 191                 snprintf(name, sizeof(name), "/dev/%s", entry.d_name);
 192                 DEBUG("Found device %s", name);
 193                 if (strstr(target, "serial8250")) {
 194                         /* The serial8250 driver has a hardcoded number of ports.
 195                          * The only way to tell which actually exist on a given system
 196                          * is to try to open them and make an ioctl call. */
 197                         DEBUG("serial8250 device, attempting to open");
 198                         if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0) {
 199                                 DEBUG("open failed, skipping");
 200                                 continue;
 201                         }
 202 #ifdef HAVE_SERIAL_STRUCT
 203                         ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
 204 #endif
 205                         close(fd);
 206 #ifdef HAVE_SERIAL_STRUCT
 207                         if (ioctl_result != 0) {
 208                                 DEBUG("ioctl failed, skipping");
 209                                 continue;
 210                         }
 211                         if (serial_info.type == PORT_UNKNOWN) {
 212                                 DEBUG("port type is unknown, skipping");
 213                                 continue;
 214                         }
 215 #endif
 216                 }
 217                 DEBUG("Found port %s", name);
 218                 *list = list_append(*list, name);
 219                 if (!list) {
 220                         SET_ERROR(ret, SP_ERR_MEM, "list append failed");
 221                         break;
 222                 }
 223         }
 224         closedir(dir);
 225
 226         return ret;
 227 }