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