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
  40         if (strncmp(port->name, "/dev/", 5))
  41                 RETURN_ERROR(SP_ERR_ARG, "Device name not recognized");
  42
  43         snprintf(file_name, sizeof(file_name), "/sys/class/tty/%s", dev);
  44         count = readlink(file_name, file_name, sizeof(file_name));
  45         if (count <= 0 || count >= (int)(sizeof(file_name) - 1))
  46                 RETURN_ERROR(SP_ERR_ARG, "Device not found");
  47         file_name[count] = 0;
  48         if (strstr(file_name, "bluetooth"))
  49                 port->transport = SP_TRANSPORT_BLUETOOTH;
  50         else if (strstr(file_name, "usb"))
  51                 port->transport = SP_TRANSPORT_USB;
  52
  53         if (port->transport == SP_TRANSPORT_USB) {
  54                 for (i = 0; i < 5; i++) {
  55                         strcat(sub_dir, "../");
  56
  57                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "busnum");
  58                         if (!(file = fopen(file_name, "r")))
  59                                 continue;
  60                         count = fscanf(file, "%d", &bus);
  61                         fclose(file);
  62                         if (count != 1)
  63                                 continue;
  64
  65                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "devnum");
  66                         if (!(file = fopen(file_name, "r")))
  67                                 continue;
  68                         count = fscanf(file, "%d", &address);
  69                         fclose(file);
  70                         if (count != 1)
  71                                 continue;
  72
  73                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "idVendor");
  74                         if (!(file = fopen(file_name, "r")))
  75                                 continue;
  76                         count = fscanf(file, "%4x", &vid);
  77                         fclose(file);
  78                         if (count != 1)
  79                                 continue;
  80
  81                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "idProduct");
  82                         if (!(file = fopen(file_name, "r")))
  83                                 continue;
  84                         count = fscanf(file, "%4x", &pid);
  85                         fclose(file);
  86                         if (count != 1)
  87                                 continue;
  88
  89                         port->usb_bus = bus;
  90                         port->usb_address = address;
  91                         port->usb_vid = vid;
  92                         port->usb_pid = pid;
  93
  94                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "product");
  95                         if ((file = fopen(file_name, "r"))) {
  96                                 if ((ptr = fgets(description, sizeof(description), file))) {
  97                                         ptr = description + strlen(description) - 1;
  98                                         if (ptr >= description && *ptr == '\n')
  99                                                 *ptr = 0;
 100                                         port->description = strdup(description);
 101                                 }
 102                                 fclose(file);
 103                         }
 104                         if (!file || !ptr)
 105                                 port->description = strdup(dev);
 106
 107                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "manufacturer");
 108                         if ((file = fopen(file_name, "r"))) {
 109                                 if ((ptr = fgets(manufacturer, sizeof(manufacturer), file))) {
 110                                         ptr = manufacturer + strlen(manufacturer) - 1;
 111                                         if (ptr >= manufacturer && *ptr == '\n')
 112                                                 *ptr = 0;
 113                                         port->usb_manufacturer = strdup(manufacturer);
 114                                 }
 115                                 fclose(file);
 116                         }
 117
 118                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "product");
 119                         if ((file = fopen(file_name, "r"))) {
 120                                 if ((ptr = fgets(product, sizeof(product), file))) {
 121                                         ptr = product + strlen(product) - 1;
 122                                         if (ptr >= product && *ptr == '\n')
 123                                                 *ptr = 0;
 124                                         port->usb_product = strdup(product);
 125                                 }
 126                                 fclose(file);
 127                         }
 128
 129                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "serial");
 130                         if ((file = fopen(file_name, "r"))) {
 131                                 if ((ptr = fgets(serial, sizeof(serial), file))) {
 132                                         ptr = serial + strlen(serial) - 1;
 133                                         if (ptr >= serial && *ptr == '\n')
 134                                                 *ptr = 0;
 135                                         port->usb_serial = strdup(serial);
 136                                 }
 137                                 fclose(file);
 138                         }
 139
 140                         /* If present, add serial to description for better identification. */
 141                         if (port->usb_serial && strlen(port->usb_serial)) {
 142                                 snprintf(description, sizeof(description),
 143                                         "%s - %s", port->description, port->usb_serial);
 144                                 if (port->description)
 145                                         free(port->description);
 146                                 port->description = strdup(description);
 147                         }
 148
 149                         break;
 150                 }
 151         } else {
 152                 port->description = strdup(dev);
 153
 154                 if (port->transport == SP_TRANSPORT_BLUETOOTH) {
 155                         snprintf(file_name, sizeof(file_name), dir_name, dev, "", "address");
 156                         if ((file = fopen(file_name, "r"))) {
 157                                 if ((ptr = fgets(baddr, sizeof(baddr), file))) {
 158                                         ptr = baddr + strlen(baddr) - 1;
 159                                         if (ptr >= baddr && *ptr == '\n')
 160                                                 *ptr = 0;
 161                                         port->bluetooth_address = strdup(baddr);
 162                                 }
 163                                 fclose(file);
 164                         }
 165                 }
 166         }
 167
 168         RETURN_OK();
 169 }
 170
 171 SP_PRIV enum sp_return list_ports(struct sp_port ***list)
 172 {
 173         char name[PATH_MAX], target[PATH_MAX];
 174         struct dirent entry, *result;
 175 #ifdef HAVE_SERIAL_STRUCT
 176         struct serial_struct serial_info;
 177         int ioctl_result;
 178 #endif
 179         char buf[sizeof(entry.d_name) + 16];
 180         int len, fd;
 181         DIR *dir;
 182         int ret = SP_OK;
 183
 184         DEBUG("Enumerating tty devices");
 185         if (!(dir = opendir("/sys/class/tty")))
 186                 RETURN_FAIL("Could not open /sys/class/tty");
 187
 188         DEBUG("Iterating over results");
 189         while (!readdir_r(dir, &entry, &result) && result) {
 190                 snprintf(buf, sizeof(buf), "/sys/class/tty/%s", entry.d_name);
 191                 len = readlink(buf, target, sizeof(target));
 192                 if (len <= 0 || len >= (int)(sizeof(target) - 1))
 193                         continue;
 194                 target[len] = 0;
 195                 if (strstr(target, "virtual"))
 196                         continue;
 197                 snprintf(name, sizeof(name), "/dev/%s", entry.d_name);
 198                 DEBUG_FMT("Found device %s", name);
 199                 if (strstr(target, "serial8250")) {
 200                         /*
 201                          * The serial8250 driver has a hardcoded number of ports.
 202                          * The only way to tell which actually exist on a given system
 203                          * is to try to open them and make an ioctl call.
 204                          */
 205                         DEBUG("serial8250 device, attempting to open");
 206                         if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0) {
 207                                 DEBUG("Open failed, skipping");
 208                                 continue;
 209                         }
 210 #ifdef HAVE_SERIAL_STRUCT
 211                         ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
 212 #endif
 213                         close(fd);
 214 #ifdef HAVE_SERIAL_STRUCT
 215                         if (ioctl_result != 0) {
 216                                 DEBUG("ioctl failed, skipping");
 217                                 continue;
 218                         }
 219                         if (serial_info.type == PORT_UNKNOWN) {
 220                                 DEBUG("Port type is unknown, skipping");
 221                                 continue;
 222                         }
 223 #endif
 224                 }
 225                 DEBUG_FMT("Found port %s", name);
 226                 *list = list_append(*list, name);
 227                 if (!list) {
 228                         SET_ERROR(ret, SP_ERR_MEM, "List append failed");
 229                         break;
 230                 }
 231         }
 232         closedir(dir);
 233
 234         return ret;
 235 }