Publish link state info to the snode

cjdelisle · Oct 4, 2018 · ac9e0c0 · ac9e0c0
1 parent 764107e
commit ac9e0c0
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Showing 11 changed files with 437 additions and 109 deletions.
diff --git a/subnode/LinkState.h b/subnode/LinkState.h
@@ -15,10 +15,13 @@
 #ifndef LinkState_H
 #define LinkState_H
 
+#include "benc/String.h"
 #include "util/VarInt.h"
 #include "wire/Message.h"
+#include "wire/Announce.h"
 
 #include <stdint.h>
+#include <stdbool.h>
 
 #define LinkState_SLOTS 18
 
@@ -27,39 +30,116 @@ struct LinkState {
     uint16_t dropSlots[LinkState_SLOTS];
     uint32_t kbRecvSlots[LinkState_SLOTS];
     uint32_t samples;
-};
-/*
-struct LinkState_AllPeers {
-
+    uint16_t nodeId;
 };
 
-static int LinkState_encode(struct Message* msg, struct LinkState* ls, int lastSamples)
+static inline int LinkState_encode(
+    struct Message* msg,
+    struct LinkState* ls,
+    uint32_t lastSamples)
 {
+    // Only encode the message if there is at least 255 bytes of headspace
+    // We can then encode as many as possible and finally pop one which spills over the
+    // size limit and then encode it again in the next message.
+    if (msg->padding < 255) { return 1; }
+
     struct VarInt_Iter iter = {
         .ptr = msg->bytes,
         .end = msg->bytes,
         .start = &msg->bytes[-msg->padding]
     };
-    if (iter.end - iter.start > 255) { iter.start = &iter.end[-255]; }
-
-    int startingPoint = ls->samples - lastSamples;
 
+    // Take the newest X entries where X = MIN(ls->samples - lastSamples, LinkState_SLOTS)
+    uint32_t i = ls->samples - 1;
+    int count = 0;
     int err = 0;
-    for (int i = 0; i < LinkState_SLOTS; i++) { err |= VarInt_push(&iter, ls->lagSlots[i]); }
-    for (int i = 0; i < LinkState_SLOTS; i++) { err |= VarInt_push(&iter, ls->dropSlots[i]); }
-    for (int i = 0; i < LinkState_SLOTS; i++) { err |= VarInt_push(&iter, ls->kbRecvSlots[i]); }
-    err |= VarInt_push(&iter, ls->samples);
-    err |= VarInt_push(&iter, 0xfc);
-    while ((((uintptr_t)iter.ptr) & 7) != 2) { err |= VarInt_push(&iter, 0); }
-    if (iter.end - iter.ptr) { }
-    VarInt_push(&iter, 0);
-    Announce_Type_LINK_STATE
-    err |= VarInt_push(&iter, 0xfc);
-    if (!err) {
-        Message_shift(msg, iter.end - iter.ptr )
+    for (; i >= lastSamples && count < LinkState_SLOTS; i--, count++) {
+        int idx = i % LinkState_SLOTS;
+        err |= VarInt_push(&iter, ls->kbRecvSlots[idx]);
+        err |= VarInt_push(&iter, ls->dropSlots[idx]);
+        err |= VarInt_push(&iter, ls->lagSlots[idx]);
+    }
+    if (err) { return 1; }
+
+    // index of the first slot which should be updated when parsing
+    Assert_true(!VarInt_push(&iter, (i + 1) % LinkState_SLOTS));
+    Assert_true(!VarInt_push(&iter, ls->nodeId));
+
+    int beginLength = msg->length;
+    Message_shift(msg, (msg->bytes - iter.ptr), NULL);
+    Assert_true(msg->bytes == iter.ptr);
+
+    int padCount = 0;
+    while ((uintptr_t)(&msg->bytes[-3]) & 7) {
+        Message_push8(msg, 0, NULL);
+        padCount++;
+    }
+    Message_push8(msg, padCount, NULL);
+
+    Message_push8(msg, Announce_Type_LINK_STATE, NULL);
+    int finalLength = msg->length - beginLength;
+    Message_push8(msg, finalLength + 1, NULL);
+
+    Assert_true(!((iter.end - msg->bytes) & 7));
+    return 0;
+}
+
+static inline int LinkState_mkDecoder(struct Message* msg, struct VarInt_Iter* it)
+{
+    if (!msg->length) { return 1; }
+    uint8_t len = msg->bytes[0];
+    if (msg->length < len) { return 1; }
+    if (len < 3) { return 1; }
+    it->ptr = &msg->bytes[1];
+    it->start = it->ptr;
+    it->end = &msg->bytes[len];
+    // Ok to pop this using VarInt because it's supposed to be 3, which is less than 253
+    uint64_t type = 0;
+    if (VarInt_pop(it, &type)) { return 1; }
+    if (type != Announce_Type_LINK_STATE) { return 1; }
+    // Should be < 8
+    uint64_t padCount = 0;
+    if (VarInt_pop(it, &padCount)) { return 1; }
+    for (unsigned int i = 0; i < padCount; i++) {
+        if (VarInt_pop(it, NULL)) { return 1; }
     }
+    return 0;
+}
 
+static inline int LinkState_getNodeId(const struct VarInt_Iter* iter, uint32_t* nodeId)
+{
+    struct VarInt_Iter it;
+    VarInt_clone(&it, iter);
+    uint64_t id;
+    if (VarInt_pop(&it, &id)) { return 1; }
+    *nodeId = id;
+    return 0;
+}
+
+#define LinkState_POP(it) (__extension__ ({ \
+    uint64_t x; \
+    if (VarInt_pop((it), &x)) { return 1; } \
+    x; \
+}))
+
+static inline int LinkState_decode(const struct VarInt_Iter* iter, struct LinkState* ls)
+{
+    struct VarInt_Iter it;
+    VarInt_clone(&it, iter);
+    ls->nodeId = LinkState_POP(&it);
+    uint32_t i = LinkState_POP(&it);
+    uint32_t count = 0;
+    if (i >= LinkState_SLOTS) { return 1; }
+    for (;;) {
+        if (it.ptr == it.end) { break; }
+        ls->lagSlots[i] = LinkState_POP(&it);
+        ls->dropSlots[i] = LinkState_POP(&it);
+        ls->kbRecvSlots[i] = LinkState_POP(&it);
+        i = (i + 1) % LinkState_SLOTS;
+        count++;
+    }
+    ls->samples += count;
+    return 0;
 }
-*/
 
 #endif