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;
  29         unsigned int vid, pid;
  30         char manufacturer[128], product[128], serial[128];
  31         char baddr[32];
  32         const char dir_name[] = "/sys/class/tty/%s/device/%s%s";
  33         char sub_dir[32] = "", file_name[PATH_MAX];
  34         char *ptr, *dev = port->name + 5;
  35         FILE *file;
  36         int i, count;
  37
  38         if (strncmp(port->name, "/dev/", 5))
  39                 RETURN_ERROR(SP_ERR_ARG, "Device name not recognized.");
  40
  41         snprintf(file_name, sizeof(file_name), "/sys/class/tty/%s", dev);
  42         count = readlink(file_name, file_name, sizeof(file_name));
  43         if (count <= 0 || count >= (int) sizeof(file_name)-1)
  44                 RETURN_ERROR(SP_ERR_ARG, "Device not found.");
  45         file_name[count] = 0;
  46         if (strstr(file_name, "bluetooth"))
  47                 port->transport = SP_TRANSPORT_BLUETOOTH;
  48         else if (strstr(file_name, "usb"))
  49                 port->transport = SP_TRANSPORT_USB;
  50
  51         if (port->transport == SP_TRANSPORT_USB) {
  52                 for (i=0; i<5; i++) {
  53                         strcat(sub_dir, "../");
  54
  55                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "busnum");
  56                         if (!(file = fopen(file_name, "r")))
  57                                 continue;
  58                         count = fscanf(file, "%d", &bus);
  59                         fclose(file);
  60                         if (count != 1)
  61                                 continue;
  62
  63                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "devnum");
  64                         if (!(file = fopen(file_name, "r")))
  65                                 continue;
  66                         count = fscanf(file, "%d", &address);
  67                         fclose(file);
  68                         if (count != 1)
  69                                 continue;
  70
  71                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "idVendor");
  72                         if (!(file = fopen(file_name, "r")))
  73                                 continue;
  74                         count = fscanf(file, "%4x", &vid);
  75                         fclose(file);
  76                         if (count != 1)
  77                                 continue;
  78
  79                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "idProduct");
  80                         if (!(file = fopen(file_name, "r")))
  81                                 continue;
  82                         count = fscanf(file, "%4x", &pid);
  83                         fclose(file);
  84                         if (count != 1)
  85                                 continue;
  86
  87                         port->usb_bus = bus;
  88                         port->usb_address = address;
  89                         port->usb_vid = vid;
  90                         port->usb_pid = pid;
  91
  92                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "product");
  93                         if ((file = fopen(file_name, "r"))) {
  94                                 if ((ptr = fgets(description, sizeof(description), file))) {
  95                                         ptr = description + strlen(description) - 1;
  96                                         if (ptr >= description && *ptr == '\n')
  97                                                 *ptr = 0;
  98                                         port->description = strdup(description);
  99                                 }
 100                                 fclose(file);
 101                         }
 102                         if (!file || !ptr)
 103                                 port->description = strdup(dev);
 104
 105                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "manufacturer");
 106                         if ((file = fopen(file_name, "r"))) {
 107                                 if ((ptr = fgets(manufacturer, sizeof(manufacturer), file))) {
 108                                         ptr = manufacturer + strlen(manufacturer) - 1;
 109                                         if (ptr >= manufacturer && *ptr == '\n')
 110                                                 *ptr = 0;
 111                                         port->usb_manufacturer = strdup(manufacturer);
 112                                 }
 113                                 fclose(file);
 114                         }
 115
 116                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "product");
 117                         if ((file = fopen(file_name, "r"))) {
 118                                 if ((ptr = fgets(product, sizeof(product), file))) {
 119                                         ptr = product + strlen(product) - 1;
 120                                         if (ptr >= product && *ptr == '\n')
 121                                                 *ptr = 0;
 122                                         port->usb_product = strdup(product);
 123                                 }
 124                                 fclose(file);
 125                         }
 126
 127                         snprintf(file_name, sizeof(file_name), dir_name, dev, sub_dir, "serial");
 128                         if ((file = fopen(file_name, "r"))) {
 129                                 if ((ptr = fgets(serial, sizeof(serial), file))) {
 130                                         ptr = serial + strlen(serial) - 1;
 131                                         if (ptr >= serial && *ptr == '\n')
 132                                                 *ptr = 0;
 133                                         port->usb_serial = strdup(serial);
 134                                 }
 135                                 fclose(file);
 136                         }
 137
 138                         break;
 139                 }
 140         } else {
 141                 port->description = strdup(dev);
 142
 143                 if (port->transport == SP_TRANSPORT_BLUETOOTH) {
 144                         snprintf(file_name, sizeof(file_name), dir_name, dev, "", "address");
 145                         if ((file = fopen(file_name, "r"))) {
 146                                 if ((ptr = fgets(baddr, sizeof(baddr), file))) {
 147                                         ptr = baddr + strlen(baddr) - 1;
 148                                         if (ptr >= baddr && *ptr == '\n')
 149                                                 *ptr = 0;
 150                                         port->bluetooth_address = strdup(baddr);
 151                                 }
 152                                 fclose(file);
 153                         }
 154                 }
 155         }
 156
 157         RETURN_OK();
 158 }
 159
 160 SP_PRIV enum sp_return list_ports(struct sp_port ***list)
 161 {
 162         char name[PATH_MAX], target[PATH_MAX];
 163         struct dirent entry, *result;
 164 #ifdef HAVE_SERIAL_STRUCT
 165         struct serial_struct serial_info;
 166         int ioctl_result;
 167 #endif
 168 #ifndef HAVE_READLINKAT
 169         char buf[sizeof(entry.d_name) + 16];
 170 #endif
 171         int len, fd;
 172         DIR *dir;
 173         int ret = SP_OK;
 174
 175         DEBUG("Enumerating tty devices");
 176         if (!(dir = opendir("/sys/class/tty")))
 177                 RETURN_FAIL("could not open /sys/class/tty");
 178
 179         DEBUG("Iterating over results");
 180         while (!readdir_r(dir, &entry, &result) && result) {
 181 #ifdef HAVE_READLINKAT
 182                 len = readlinkat(dirfd(dir), entry.d_name, target, sizeof(target));
 183 #else
 184                 snprintf(buf, sizeof(buf), "/sys/class/tty/%s", entry.d_name);
 185                 len = readlink(buf, target, sizeof(target));
 186 #endif
 187                 if (len <= 0 || len >= (int) sizeof(target)-1)
 188                         continue;
 189                 target[len] = 0;
 190                 if (strstr(target, "virtual"))
 191                         continue;
 192                 snprintf(name, sizeof(name), "/dev/%s", entry.d_name);
 193                 DEBUG_FMT("Found device %s", name);
 194                 if (strstr(target, "serial8250")) {
 195                         /* The serial8250 driver has a hardcoded number of ports.
 196                          * The only way to tell which actually exist on a given system
 197                          * is to try to open them and make an ioctl call. */
 198                         DEBUG("serial8250 device, attempting to open");
 199                         if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0) {
 200                                 DEBUG("open failed, skipping");
 201                                 continue;
 202                         }
 203 #ifdef HAVE_SERIAL_STRUCT
 204                         ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
 205 #endif
 206                         close(fd);
 207 #ifdef HAVE_SERIAL_STRUCT
 208                         if (ioctl_result != 0) {
 209                                 DEBUG("ioctl failed, skipping");
 210                                 continue;
 211                         }
 212                         if (serial_info.type == PORT_UNKNOWN) {
 213                                 DEBUG("port type is unknown, skipping");
 214                                 continue;
 215                         }
 216 #endif
 217                 }
 218                 DEBUG_FMT("Found port %s", name);
 219                 *list = list_append(*list, name);
 220                 if (!list) {
 221                         SET_ERROR(ret, SP_ERR_MEM, "list append failed");
 222                         break;
 223                 }
 224         }
 225         closedir(dir);
 226
 227         return ret;
 228 }