handler_virt_tender.c

   1 #include "handler_virt_tender.h"
   2 #include <float.h>
   3 #include <string.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <unistd.h>
   7
   8 #ifdef NOTRACE
   9     #define TRACE(...)
  10 #else
  11     #include <cherokee/cherokee.h>
  12 #endif
  13
  14 #include <avahi-client/client.h>
  15 #include <avahi-client/publish.h>
  16 #include <avahi-client/lookup.h>
  17
  18 #include <avahi-common/alternative.h>
  19 #include <avahi-common/simple-watch.h>
  20 #include <avahi-common/malloc.h>
  21 #include <avahi-common/error.h>
  22 #include <avahi-common/timeval.h>
  23 #include <avahi-common/thread-watch.h>
  24
  25 static void entry_group_callback(AvahiEntryGroup *g, AvahiEntryGroupState state, AVAHI_GCC_UNUSED void *userdata) {
  26     switch (state) {
  27         case AVAHI_ENTRY_GROUP_ESTABLISHED :
  28             /* The entry group has been established successfully */
  29             break;
  30
  31         case AVAHI_ENTRY_GROUP_COLLISION : {
  32             /* A service name collision with a remote service
  33              * happened. */
  34             break;
  35         }
  36
  37         case AVAHI_ENTRY_GROUP_FAILURE :
  38             /* Some kind of failure happened while we were registering our services */
  39             break;
  40
  41         case AVAHI_ENTRY_GROUP_UNCOMMITED:
  42         case AVAHI_ENTRY_GROUP_REGISTERING:
  43             ;
  44     }
  45 }
  46
  47 static void tender_resolve_callback(
  48     AvahiServiceResolver *r,
  49     AVAHI_GCC_UNUSED AvahiIfIndex interface,
  50     AVAHI_GCC_UNUSED AvahiProtocol protocol,
  51     AvahiResolverEvent event,
  52     const char *name,
  53     const char *type,
  54     const char *domain,
  55     const char *host_name,
  56     const AvahiAddress *address,
  57     uint16_t port,
  58     AvahiStringList *txt,
  59     AvahiLookupResultFlags flags,
  60     void* userdata) {
  61
  62     tender_t *tender = userdata;
  63
  64     assert(r);
  65
  66     /* Called whenever a service has been resolved successfully or timed out */
  67
  68     switch (event) {
  69         case AVAHI_RESOLVER_FAILURE:
  70             TRACE("avahi", "(Resolver) FAILURE!\n");
  71             avahi_service_resolver_free(r);
  72             break;
  73
  74         case AVAHI_RESOLVER_FOUND: {
  75             char a[AVAHI_ADDRESS_STR_MAX], *t;
  76             AvahiStringList *needle;
  77
  78             TRACE("avahi", "(Resolver) Service '%s' of type '%s' in domain '%s':\n", name, type, domain);
  79
  80             avahi_address_snprint(a, sizeof(a), address);
  81             t = avahi_string_list_to_string(txt);
  82             TRACE("avahi",
  83                     "\t%s:%u (%s)\n"
  84                     "\tTXT=%s\n"
  85                     "\tcookie is %u\n"
  86                     "\tis_local: %i\n"
  87                     "\tour_own: %i\n"
  88                     "\twide_area: %i\n"
  89                     "\tmulticast: %i\n"
  90                     "\tcached: %i\n",
  91                     host_name, port, a,
  92                     t,
  93                     avahi_string_list_get_service_cookie(txt),
  94                     !!(flags & AVAHI_LOOKUP_RESULT_LOCAL),
  95                     !!(flags & AVAHI_LOOKUP_RESULT_OUR_OWN),
  96                     !!(flags & AVAHI_LOOKUP_RESULT_WIDE_AREA),
  97                     !!(flags & AVAHI_LOOKUP_RESULT_MULTICAST),
  98                     !!(flags & AVAHI_LOOKUP_RESULT_CACHED));
  99
 100
 101             avahi_free(t);
 102
 103             if (tender->name) {
 104                 unsigned int len = strlen(tender->name);
 105                 if (strlen(name) > len && name[len] == '.' && strncmp(tender->name, name, len) == 0) {
 106                     if ((needle = avahi_string_list_find (txt, "cost")) != NULL) {
 107
 108                         float amount;
 109                         char *cost;
 110                         avahi_string_list_get_pair (needle, NULL, &cost, NULL);
 111                         amount = atof(cost);
 112
 113                         TRACE("tender", "%s will run %s for the cost of L$W %f\n", host_name, tender->name, amount);
 114                         if (amount < tender->cost) {
 115                             /* TODO: LOCK */
 116                             tender->cost = amount;
 117                             free(tender->dom);
 118                             tender->dom = strdup(host_name);
 119                             TRACE("tender", "We will consider %ss offer!\n", tender->dom);
 120                         }
 121
 122                         avahi_free(cost);
 123                     }
 124                 }
 125             }
 126             break;
 127         }
 128     }
 129 }
 130
 131 static void tender_browse_callback(
 132     AvahiServiceBrowser *b,
 133     AvahiIfIndex interface,
 134     AvahiProtocol protocol,
 135     AvahiBrowserEvent event,
 136     const char *name,
 137     const char *type,
 138     const char *domain,
 139     AVAHI_GCC_UNUSED AvahiLookupResultFlags flags,
 140     void* userdata) {
 141         AvahiClient *c;
 142         assert(b);
 143
 144         c = avahi_service_browser_get_client(b);
 145
 146     /* Called whenever a new services becomes available on the LAN or is removed from the LAN */
 147
 148     switch (event) {
 149         case AVAHI_BROWSER_FAILURE:
 150             TRACE("avahi", "(Browser) %s\n", avahi_strerror(avahi_client_errno(c)));
 151             return;
 152
 153         case AVAHI_BROWSER_NEW:
 154             TRACE("avahi", "(Browser) NEW: service '%s' of type '%s' in domain '%s'\n", name, type, domain);
 155
 156             /* We ignore the returned resolver object. In the callback
 157                function we free it. If the server is terminated before
 158                the callback function is called the server will free
 159                the resolver for us. */
 160
 161             if (!(avahi_service_resolver_new(c, interface, protocol, name, type, domain, AVAHI_PROTO_UNSPEC, 0, tender_resolve_callback, userdata)))
 162                 TRACE("avahi", "Failed to resolve service '%s': %s\n", name, avahi_strerror(avahi_client_errno(c)));
 163
 164             break;
 165
 166         case AVAHI_BROWSER_REMOVE:
 167             TRACE("avahi", "%s, (Browser) REMOVE: service '%s' of type '%s' in domain '%s'\n", __func__, name, type, domain);
 168             break;
 169
 170         case AVAHI_BROWSER_ALL_FOR_NOW:
 171         case AVAHI_BROWSER_CACHE_EXHAUSTED:
 172             TRACE("avahi", "(Browser) %s\n", event == AVAHI_BROWSER_CACHE_EXHAUSTED ? "CACHE_EXHAUSTED" : "ALL_FOR_NOW");
 173             break;
 174     }
 175 }
 176
 177 char * create_tender(AvahiClient *client, AvahiThreadedPoll *threaded_poll, const char *name, unsigned long memory) {
 178     char txt[255];
 179     tender_t best_tender;
 180
 181     snprintf(txt, 253, "memory=%lu", memory);
 182     txt[254] = '\0';
 183
 184     best_tender.name = name;
 185     best_tender.cost = FLT_MAX;
 186     best_tender.dom  = NULL;
 187
 188     avahi_threaded_poll_lock(threaded_poll);
 189     AvahiServiceBrowser *sb = avahi_service_browser_new(client, AVAHI_IF_UNSPEC,
 190                                                         AVAHI_PROTO_UNSPEC, "_tender._tcp",
 191                                                         NULL, 0, tender_browse_callback, &best_tender);
 192
 193     if (sb == NULL) {
 194         TRACE("avahi", "For whatever reason the sb is NULL\n");
 195     } else {
 196         AvahiEntryGroup *group = avahi_entry_group_new(client, entry_group_callback, NULL);
 197
 198         if (group == NULL) {
 199             TRACE("avahi", "For whatever reason the group is NULL\n");
 200         } else {
 201             avahi_entry_group_add_service(group, AVAHI_IF_UNSPEC, AVAHI_PROTO_UNSPEC, 0,
 202                                           best_tender.name, "_offer._tcp", NULL, NULL, 651, txt, NULL, NULL);
 203             avahi_entry_group_commit(group);
 204             avahi_threaded_poll_unlock(threaded_poll);
 205
 206             sleep(3); /* we are for quick bidding ;) */
 207
 208             avahi_threaded_poll_lock(threaded_poll);
 209             avahi_entry_group_free(group);
 210         }
 211
 212         avahi_service_browser_free(sb);
 213     }
 214     avahi_threaded_poll_unlock(threaded_poll);
 215
 216     return best_tender.dom;
 217 }