ring.c

   1 #include "server.h"
   2
   3 static FILE *urandom;
   4
   5 AVL_TREE(rings, udebug_id_cmp, true, NULL);
   6
   7 struct client_ring *client_ring_get_by_id(struct client *cl, uint32_t id)
   8 {
   9         struct client_ring *r;
  10
  11         list_for_each_entry(r, &cl->bufs, list)
  12                 if (r->id == id)
  13                         return r;
  14
  15         return NULL;
  16 }
  17
  18 static uint32_t gen_ring_id(void)
  19 {
  20         uint32_t val = 0;
  21
  22         if (!urandom && (urandom = fopen("/dev/urandom", "r")) == NULL)
  23                 return 0;
  24
  25         if (fread(&val, sizeof(val), 1, urandom) != 1)
  26                 return 0;
  27
  28         return val;
  29 }
  30
  31 struct client_ring *client_ring_alloc(struct client *cl)
  32 {
  33         enum {
  34                 RING_ATTR_NAME,
  35                 RING_ATTR_FLAGS,
  36                 __RING_ATTR_MAX,
  37         };
  38         static const struct blobmsg_policy policy[__RING_ATTR_MAX] = {
  39                 [RING_ATTR_NAME] = { "name", BLOBMSG_TYPE_STRING },
  40                 [RING_ATTR_FLAGS] = { "flags", BLOBMSG_TYPE_ARRAY },
  41         };
  42         struct udebug_client_msg *msg = &cl->rx_buf.msg;
  43         struct blob_attr *tb[__RING_ATTR_MAX], *meta;
  44         struct client_ring *r;
  45         size_t meta_len;
  46
  47         if (cl->rx_fd < 0) {
  48                 DC(2, cl, "missing file descriptor");
  49                 return NULL;
  50         }
  51
  52         meta_len = blob_pad_len(&cl->rx_buf.data);
  53         r = calloc_a(sizeof(*r), &meta, meta_len);
  54         memcpy(meta, cl->rx_buf.buf, meta_len);
  55
  56         blobmsg_parse_attr(policy, __RING_ATTR_MAX, tb, meta);
  57         if (!tb[RING_ATTR_NAME]) {
  58                 DC(2, cl, "missing ring name");
  59                 close(cl->rx_fd);
  60                 free(r);
  61                 return NULL;
  62         }
  63
  64         r->name = blobmsg_get_string(tb[RING_ATTR_NAME]);
  65         r->flags = tb[RING_ATTR_FLAGS];
  66
  67         r->cl = cl;
  68         r->id = msg->id;
  69         r->fd = cl->rx_fd;
  70         cl->rx_fd = -1;
  71         r->ring_size = msg->ring_size;
  72         r->data_size = msg->data_size;
  73         list_add_tail(&r->list, &cl->bufs);
  74
  75         r->node.key = (void *)(uintptr_t)gen_ring_id();
  76         avl_insert(&rings, &r->node);
  77         udebug_ubus_ring_notify(r, true);
  78         DC(2, cl, "add ring %d [%x] ring_size=%x data_size=%x", r->id, ring_id(r), r->ring_size, r->data_size);
  79
  80         return r;
  81 }
  82
  83 void client_ring_free(struct client_ring *r)
  84 {
  85         DC(2, r->cl, "free ring %d [%x]", r->id, ring_id(r));
  86         udebug_ubus_ring_notify(r, false);
  87         avl_delete(&rings, &r->node);
  88         list_del(&r->list);
  89         close(r->fd);
  90         free(r);
  91 }