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