main.c

   1 #include <stdio.h>
   2 #include <getopt.h>
   3 #include <stdbool.h>
   4 #include <ctype.h>
   5
   6 #include <libubox/blobmsg_json.h>
   7 #include <libubox/avl.h>
   8 #include <libubox/avl-cmp.h>
   9 #include "switch.h"
  10
  11 #define DEFAULT_CONFIG "/etc/usb-mode.json"
  12
  13 struct device {
  14         struct avl_node avl;
  15         struct blob_attr *data;
  16 };
  17
  18 static int verbose = 0;
  19 static const char *config_file = DEFAULT_CONFIG;
  20 static struct blob_buf conf;
  21
  22 static struct blob_attr **messages;
  23 static int n_messages;
  24
  25 static struct avl_tree devices;
  26
  27 static struct libusb_context *usb;
  28 static struct libusb_device **usbdevs;
  29 static int n_usbdevs;
  30
  31 static int hex2num(char c)
  32 {
  33         if (c >= '0' && c <= '9')
  34                 return c - '0';
  35
  36         c = toupper(c);
  37         if (c >= 'A' && c <= 'F')
  38                 return c - 'A' + 10;
  39
  40         return -1;
  41 }
  42
  43 static int hex2byte(const char *hex)
  44 {
  45         int a, b;
  46
  47         a = hex2num(*hex++);
  48         if (a < 0)
  49                 return -1;
  50
  51         b = hex2num(*hex++);
  52         if (b < 0)
  53                 return -1;
  54
  55         return (a << 4) | b;
  56 }
  57
  58 static int hexstr2bin(const char *hex, char *buffer, int len)
  59 {
  60         const char *ipos = hex;
  61         char *opos = buffer;
  62         int i, a;
  63
  64         for (i = 0; i < len; i++) {
  65                 a = hex2byte(ipos);
  66                 if (a < 0)
  67                         return -1;
  68
  69                 *opos++ = a;
  70                 ipos += 2;
  71         }
  72
  73         return 0;
  74 }
  75
  76 static bool convert_message(struct blob_attr *attr)
  77 {
  78         char *data;
  79         int len;
  80
  81         if (!attr)
  82                 return true;
  83
  84         data = blobmsg_data(attr);
  85         len = strlen(data);
  86         if (len % 2)
  87                 return false;
  88
  89         return !hexstr2bin(data, data, len / 2);
  90 }
  91
  92 static int parse_config(void)
  93 {
  94         enum {
  95                 CONF_MESSAGES,
  96                 CONF_DEVICES,
  97                 __CONF_MAX
  98         };
  99         static const struct blobmsg_policy policy[__CONF_MAX] = {
 100                 [CONF_MESSAGES] = { .name = "messages", .type = BLOBMSG_TYPE_ARRAY },
 101                 [CONF_DEVICES] = { .name = "devices", .type = BLOBMSG_TYPE_TABLE },
 102         };
 103         struct blob_attr *tb[__CONF_MAX];
 104         struct blob_attr *cur;
 105         struct device *dev;
 106         int rem;
 107
 108         blobmsg_parse(policy, __CONF_MAX, tb, blob_data(conf.head), blob_len(conf.head));
 109         if (!tb[CONF_MESSAGES] || !tb[CONF_DEVICES]) {
 110                 fprintf(stderr, "Configuration incomplete\n");
 111                 return -1;
 112         }
 113
 114         blobmsg_for_each_attr(cur, tb[CONF_MESSAGES], rem)
 115                 n_messages++;
 116
 117         messages = calloc(n_messages, sizeof(*messages));
 118         n_messages = 0;
 119         blobmsg_for_each_attr(cur, tb[CONF_MESSAGES], rem) {
 120                 if (!convert_message(cur)) {
 121                         fprintf(stderr, "Invalid data in message %d\n", n_messages);
 122                         return -1;
 123                 }
 124                 messages[n_messages++] = cur;
 125         }
 126
 127         blobmsg_for_each_attr(cur, tb[CONF_DEVICES], rem) {
 128             dev = calloc(1, sizeof(*dev));
 129             dev->avl.key = blobmsg_name(cur);
 130             dev->data = cur;
 131             avl_insert(&devices, &dev->avl);
 132         }
 133
 134         return 0;
 135 }
 136
 137 static int usage(const char *prog)
 138 {
 139         fprintf(stderr, "Usage: %s <command> <options>\n"
 140                 "Commands:\n"
 141                 "       -l              List matching devices\n"
 142                 "       -s              Modeswitch matching devices\n"
 143                 "\n"
 144                 "Options:\n"
 145                 "       -v              Verbose output\n"
 146                 "       -c <file>       Set configuration file to <file> (default: %s)\n"
 147                 "\n", prog, DEFAULT_CONFIG);
 148         return 1;
 149 }
 150
 151 typedef void (*cmd_cb_t)(struct usbdev_data *data);
 152
 153 static struct blob_attr *
 154 find_dev_data(struct usbdev_data *data, struct device *dev)
 155 {
 156         struct blob_attr *cur;
 157         int rem;
 158
 159         blobmsg_for_each_attr(cur, dev->data, rem) {
 160                 const char *name = blobmsg_name(cur);
 161                 const char *next;
 162                 char *val;
 163
 164                 if (!strcmp(blobmsg_name(cur), "*"))
 165                         return cur;
 166
 167                 next = strchr(name, '=');
 168                 if (!next)
 169                         continue;
 170
 171                 next++;
 172                 if (!strncmp(name, "uMa", 3)) {
 173                         val = data->mfg;
 174                 } else if (!strncmp(name, "uPr", 3)) {
 175                         val = data->prod;
 176                 } else if (!strncmp(name, "uSe", 3)) {
 177                         val = data->serial;
 178                 } else {
 179                         /* ignore unsupported scsi attributes */
 180                         return cur;
 181                 }
 182
 183                 if (!strcmp(val, next))
 184                         return cur;
 185         }
 186
 187         return NULL;
 188 }
 189
 190 static void
 191 parse_interface_config(libusb_device *dev, struct usbdev_data *data)
 192 {
 193         struct libusb_config_descriptor *config;
 194         const struct libusb_interface *iface;
 195
 196         data->interface = -1;
 197         if (libusb_get_config_descriptor(dev, 0, &config))
 198                 return;
 199
 200         data->config = config;
 201         if (!config->bNumInterfaces)
 202                 return;
 203
 204         iface = &config->interface[0];
 205         if (!iface->num_altsetting)
 206                 return;
 207
 208         data->interface = iface->altsetting[0].bInterfaceNumber;
 209 }
 210
 211 static void iterate_devs(cmd_cb_t cb)
 212 {
 213         struct usbdev_data data;
 214         struct device *dev;
 215         int i;
 216
 217         if (!cb)
 218                 return;
 219
 220         for (i = 0; i < n_usbdevs; i++) {
 221                 memset(&data, 0, sizeof(data));
 222
 223                 if (libusb_get_device_descriptor(usbdevs[i], &data.desc))
 224                         continue;
 225
 226                 sprintf(data.idstr, "%04x:%04x", data.desc.idVendor, data.desc.idProduct);
 227
 228                 dev = avl_find_element(&devices, data.idstr, dev, avl);
 229                 if (!dev)
 230                         continue;
 231
 232                 if (libusb_open(usbdevs[i], &data.devh))
 233                         continue;
 234
 235                 libusb_get_string_descriptor_ascii(
 236                         data.devh, data.desc.iManufacturer,
 237                         (void *) data.mfg, sizeof(data.mfg));
 238                 libusb_get_string_descriptor_ascii(
 239                         data.devh, data.desc.iProduct,
 240                         (void *) data.prod, sizeof(data.prod));
 241                 libusb_get_string_descriptor_ascii(
 242                         data.devh, data.desc.iSerialNumber,
 243                         (void *) data.serial, sizeof(data.serial));
 244
 245                 parse_interface_config(usbdevs[i], &data);
 246
 247                 data.info = find_dev_data(&data, dev);
 248                 if (data.info)
 249                         cb(&data);
 250
 251                 if (data.config)
 252                         libusb_free_config_descriptor(data.config);
 253
 254                 libusb_close(data.devh);
 255         }
 256 }
 257
 258 static void handle_list(struct usbdev_data *data)
 259 {
 260         fprintf(stderr, "Found device: %s (Manufacturer: \"%s\", Product: \"%s\", Serial: \"%s\")\n",
 261                 data->idstr, data->mfg, data->prod, data->serial);
 262 }
 263
 264 int main(int argc, char **argv)
 265 {
 266         cmd_cb_t cb = NULL;
 267         int ret;
 268         int ch;
 269
 270         avl_init(&devices, avl_strcmp, false, NULL);
 271
 272         while ((ch = getopt(argc, argv, "lsc:v")) != -1) {
 273                 switch (ch) {
 274                 case 'l':
 275                         cb = handle_list;
 276                         break;
 277                 case 's':
 278                         cb = handle_switch;
 279                         break;
 280                 case 'c':
 281                         config_file = optarg;
 282                         break;
 283                 case 'v':
 284                         verbose++;
 285                         break;
 286                 default:
 287                         return usage(argv[0]);
 288                 }
 289         }
 290
 291         blob_buf_init(&conf, 0);
 292         if (!blobmsg_add_json_from_file(&conf, config_file) ||
 293             parse_config()) {
 294                 fprintf(stderr, "Failed to load config file\n");
 295                 return 1;
 296         }
 297
 298         ret = libusb_init(&usb);
 299         if (ret) {
 300                 fprintf(stderr, "Failed to initialize libusb: %s\n", libusb_error_name(ret));
 301                 return 1;
 302         }
 303
 304         n_usbdevs = libusb_get_device_list(usb, &usbdevs);
 305         iterate_devs(cb);
 306         libusb_free_device_list(usbdevs, 1);
 307         libusb_exit(usb);
 308
 309         return 0;
 310 }