P2P: Move random channel selection into a helper function

The new p2p_channel_select() function can be re-used to implement
random channel selection from a set of operating classes in all
places that need such functonality.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>

diff --git a/src/p2p/p2p_go_neg.c b/src/p2p/p2p_go_neg.c
index 7eaa8dcc26444a1f3db331a5238f76a64412595e..b1703ac8b846bdcd070be6174bbc0b19bdd6f579 100644 (file)
--- a/src/p2p/p2p_go_neg.c
+++ b/src/p2p/p2p_go_neg.c
@@ -348,6 +348,7 @@ void p2p_reselect_channel(struct p2p_data *p2p,
        int freq;
        u8 op_reg_class, op_channel;
        unsigned int i;
+       const int op_classes_5ghz[] = { 115, 124, 0 };
 
        if (p2p->own_freq_preference > 0 &&
            p2p_freq_to_channel(p2p->own_freq_preference,
@@ -438,24 +439,11 @@ void p2p_reselect_channel(struct p2p_data *p2p,
        }
 
        /* Prefer a 5 GHz channel */
-       for (i = 0; i < intersection->reg_classes; i++) {
-               struct p2p_reg_class *c = &intersection->reg_class[i];
-               if ((c->reg_class == 115 || c->reg_class == 124) &&
-                   c->channels) {
-                       unsigned int r;
-
-                       /*
-                        * Pick one of the available channels in the operating
-                        * class at random.
-                        */
-                       os_get_random((u8 *) &r, sizeof(r));
-                       r %= c->channels;
-                       p2p_dbg(p2p, "Pick possible 5 GHz channel (op_class %u channel %u) from intersection",
-                               c->reg_class, c->channel[r]);
-                       p2p->op_reg_class = c->reg_class;
-                       p2p->op_channel = c->channel[r];
-                       return;
-               }
+       if (p2p_channel_select(intersection, op_classes_5ghz,
+                              &p2p->op_reg_class, &p2p->op_channel) == 0) {
+               p2p_dbg(p2p, "Pick possible 5 GHz channel (op_class %u channel %u) from intersection",
+                       p2p->op_reg_class, p2p->op_channel);
+               return;
        }
 
        /*

diff --git a/src/p2p/p2p_i.h b/src/p2p/p2p_i.h
index 6b7f6bdfbfb2254630a41455279588c473cd7586..efc163a08cff8dc880002b0b48281d71a59b7290 100644 (file)
--- a/src/p2p/p2p_i.h
+++ b/src/p2p/p2p_i.h
@@ -581,6 +581,8 @@ int p2p_channels_includes(const struct p2p_channels *channels, u8 reg_class,
                          u8 channel);
 void p2p_channels_dump(struct p2p_data *p2p, const char *title,
                       const struct p2p_channels *chan);
+int p2p_channel_select(struct p2p_channels *chans, const int *classes,
+                      u8 *op_class, u8 *op_channel);
 
 /* p2p_parse.c */
 int p2p_parse_p2p_ie(const struct wpabuf *buf, struct p2p_message *msg);

diff --git a/src/p2p/p2p_utils.c b/src/p2p/p2p_utils.c
index a3dcdebb0eafa52b8d087b5c779c116dfe7d862b..a579509aea8a19acc3d2410b649b56117fc11b42 100644 (file)
--- a/src/p2p/p2p_utils.c
+++ b/src/p2p/p2p_utils.c
@@ -439,3 +439,36 @@ void p2p_channels_dump(struct p2p_data *p2p, const char *title,
 
        p2p_dbg(p2p, "%s:%s", title, buf);
 }
+
+
+int p2p_channel_select(struct p2p_channels *chans, const int *classes,
+                      u8 *op_class, u8 *op_channel)
+{
+       unsigned int i, j, r;
+
+       for (i = 0; i < chans->reg_classes; i++) {
+               struct p2p_reg_class *c = &chans->reg_class[i];
+
+               if (c->channels == 0)
+                       continue;
+
+               for (j = 0; classes[j]; j++) {
+                       if (c->reg_class == classes[j])
+                               break;
+               }
+               if (!classes[j])
+                       continue;
+
+               /*
+                * Pick one of the available channels in the operating class at
+                * random.
+                */
+               os_get_random((u8 *) &r, sizeof(r));
+               r %= c->channels;
+               *op_class = c->reg_class;
+               *op_channel = c->channel[r];
+               return 0;
+       }
+
+       return -1;
+}