linux.c

   1 /*
   2  * This file is part of the libserialport project.
   3  *
   4  * Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li>
   5  * Copyright (C) 2014 Aurelien Jacobs <aurel@gnuage.org>
   6  *
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Lesser General Public License as
   9  * published by the Free Software Foundation, either version 3 of the
  10  * License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22 #include "libserialport.h"
  23 #include "libserialport_internal.h"
  24
  25 SP_PRIV enum sp_return get_port_details(struct sp_port *port)
  26 {
  27         /*
  28          * Description limited to 127 char, anything longer
  29          * would not be user friendly anyway.
  30          */
  31         char description[128];
  32         int bus, address;
  33         unsigned int vid, pid;
  34         char manufacturer[128], product[128], serial[128];
  35         char baddr[32];
  36         const char dir_name[] = "/sys/class/tty/%s/device/%s%s";
  37         char sub_dir[32] = "", file_name[PATH_MAX];
  38         char *ptr, *dev = port->name + 5;
  39         FILE *file;
  40         int i, count;
  41         struct stat statbuf;
  42
  43         if (strncmp(port->name, "/dev/", 5))
  44                 RETURN_ERROR(SP_ERR_ARG, "Device name not recognized");
  45
  46         snprintf(file_name, sizeof(file_name), "/sys/class/tty/%s", dev);
  47         if (lstat(file_name, &statbuf) == -1)
  48                 RETURN_ERROR(SP_ERR_ARG, "Device not found");
  49         if (!S_ISLNK(statbuf.st_mode))
  50                 snprintf(file_name, sizeof(file_name), "/sys/class/tty/%s/device", dev);
  51         count = readlink(file_name, file_name, sizeof(file_name));
  52         if (count <= 0 || count >= (int)(sizeof(file_name) - 1))
  53                 RETURN_ERROR(SP_ERR_ARG, "Device not found");
  54         file_name[count] = 0;
  55         if (strstr(file_name, "bluetooth"))
  56                 port->transport = SP_TRANSPORT_BLUETOOTH;
  57         else if (strstr(file_name, "usb"))
  58                 port->transport = SP_TRANSPORT_USB;
  59
  60         if (port->transport == SP_TRANSPORT_USB) {
  61                 for (i = 0; i < 5; i++) {
  62                         strcat(sub_dir, "../");
  63
  64                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "busnum");
  65                         if (!(file = fopen(file_name, "r")))
  66                                 continue;
  67                         count = fscanf(file, "%d", &bus);
  68                         fclose(file);
  69                         if (count != 1)
  70                                 continue;
  71
  72                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "devnum");
  73                         if (!(file = fopen(file_name, "r")))
  74                                 continue;
  75                         count = fscanf(file, "%d", &address);
  76                         fclose(file);
  77                         if (count != 1)
  78                                 continue;
  79
  80                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "idVendor");
  81                         if (!(file = fopen(file_name, "r")))
  82                                 continue;
  83                         count = fscanf(file, "%4x", &vid);
  84                         fclose(file);
  85                         if (count != 1)
  86                                 continue;
  87
  88                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "idProduct");
  89                         if (!(file = fopen(file_name, "r")))
  90                                 continue;
  91                         count = fscanf(file, "%4x", &pid);
  92                         fclose(file);
  93                         if (count != 1)
  94                                 continue;
  95
  96                         port->usb_bus = bus;
  97                         port->usb_address = address;
  98                         port->usb_vid = vid;
  99                         port->usb_pid = pid;
 100
 101                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "product");
 102                         if ((file = fopen(file_name, "r"))) {
 103                                 if ((ptr = fgets(description, sizeof(description), file))) {
 104                                         ptr = description + strlen(description) - 1;
 105                                         if (ptr >= description && *ptr == '\n')
 106                                                 *ptr = 0;
 107                                         port->description = strdup(description);
 108                                 }
 109                                 fclose(file);
 110                         }
 111                         if (!file || !ptr)
 112                                 port->description = strdup(dev);
 113
 114                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "manufacturer");
 115                         if ((file = fopen(file_name, "r"))) {
 116                                 if ((ptr = fgets(manufacturer, sizeof(manufacturer), file))) {
 117                                         ptr = manufacturer + strlen(manufacturer) - 1;
 118                                         if (ptr >= manufacturer && *ptr == '\n')
 119                                                 *ptr = 0;
 120                                         port->usb_manufacturer = strdup(manufacturer);
 121                                 }
 122                                 fclose(file);
 123                         }
 124
 125                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "product");
 126                         if ((file = fopen(file_name, "r"))) {
 127                                 if ((ptr = fgets(product, sizeof(product), file))) {
 128                                         ptr = product + strlen(product) - 1;
 129                                         if (ptr >= product && *ptr == '\n')
 130                                                 *ptr = 0;
 131                                         port->usb_product = strdup(product);
 132                                 }
 133                                 fclose(file);
 134                         }
 135
 136                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "serial");
 137                         if ((file = fopen(file_name, "r"))) {
 138                                 if ((ptr = fgets(serial, sizeof(serial), file))) {
 139                                         ptr = serial + strlen(serial) - 1;
 140                                         if (ptr >= serial && *ptr == '\n')
 141                                                 *ptr = 0;
 142                                         port->usb_serial = strdup(serial);
 143                                 }
 144                                 fclose(file);
 145                         }
 146
 147                         /* If present, add serial to description for better identification. */
 148                         if (port->usb_serial && strlen(port->usb_serial)) {
 149                                 snprintf(description, sizeof(description),
 150                                         "%s - %s", port->description, port->usb_serial);
 151                                 if (port->description)
 152                                         free(port->description);
 153                                 port->description = strdup(description);
 154                         }
 155
 156                         break;
 157                 }
 158         } else {
 159                 port->description = strdup(dev);
 160
 161                 if (port->transport == SP_TRANSPORT_BLUETOOTH) {
 162                         snprintf(file_name, sizeof(file_name), dir_name, dev, "", "address");
 163                         if ((file = fopen(file_name, "r"))) {
 164                                 if ((ptr = fgets(baddr, sizeof(baddr), file))) {
 165                                         ptr = baddr + strlen(baddr) - 1;
 166                                         if (ptr >= baddr && *ptr == '\n')
 167                                                 *ptr = 0;
 168                                         port->bluetooth_address = strdup(baddr);
 169                                 }
 170                                 fclose(file);
 171                         }
 172                 }
 173         }
 174
 175         RETURN_OK();
 176 }
 177
 178 SP_PRIV enum sp_return list_ports(struct sp_port ***list)
 179 {
 180         char name[PATH_MAX], target[PATH_MAX];
 181         struct dirent entry, *result;
 182 #ifdef HAVE_STRUCT_SERIAL_STRUCT
 183         struct serial_struct serial_info;
 184         int ioctl_result;
 185 #endif
 186         char buf[sizeof(entry.d_name) + 23];
 187         int len, fd;
 188         DIR *dir;
 189         int ret = SP_OK;
 190         struct stat statbuf;
 191
 192         DEBUG("Enumerating tty devices");
 193         if (!(dir = opendir("/sys/class/tty")))
 194                 RETURN_FAIL("Could not open /sys/class/tty");
 195
 196         DEBUG("Iterating over results");
 197         while (!readdir_r(dir, &entry, &result) && result) {
 198                 snprintf(buf, sizeof(buf), "/sys/class/tty/%s", entry.d_name);
 199                 if (lstat(buf, &statbuf) == -1)
 200                         continue;
 201                 if (!S_ISLNK(statbuf.st_mode))
 202                         snprintf(buf, sizeof(buf), "/sys/class/tty/%s/device", entry.d_name);
 203                 len = readlink(buf, target, sizeof(target));
 204                 if (len <= 0 || len >= (int)(sizeof(target) - 1))
 205                         continue;
 206                 target[len] = 0;
 207                 if (strstr(target, "virtual"))
 208                         continue;
 209                 snprintf(name, sizeof(name), "/dev/%s", entry.d_name);
 210                 DEBUG_FMT("Found device %s", name);
 211                 if (strstr(target, "serial8250")) {
 212                         /*
 213                          * The serial8250 driver has a hardcoded number of ports.
 214                          * The only way to tell which actually exist on a given system
 215                          * is to try to open them and make an ioctl call.
 216                          */
 217                         DEBUG("serial8250 device, attempting to open");
 218                         if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0) {
 219                                 DEBUG("Open failed, skipping");
 220                                 continue;
 221                         }
 222 #ifdef HAVE_STRUCT_SERIAL_STRUCT
 223                         ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
 224 #endif
 225                         close(fd);
 226 #ifdef HAVE_STRUCT_SERIAL_STRUCT
 227                         if (ioctl_result != 0) {
 228                                 DEBUG("ioctl failed, skipping");
 229                                 continue;
 230                         }
 231                         if (serial_info.type == PORT_UNKNOWN) {
 232                                 DEBUG("Port type is unknown, skipping");
 233                                 continue;
 234                         }
 235 #endif
 236                 }
 237                 DEBUG_FMT("Found port %s", name);
 238                 *list = list_append(*list, name);
 239                 if (!list) {
 240                         SET_ERROR(ret, SP_ERR_MEM, "List append failed");
 241                         break;
 242                 }
 243         }
 244         closedir(dir);
 245
 246         return ret;
 247 }