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-rw-r--r--src/main.c498
1 files changed, 29 insertions, 469 deletions
diff --git a/src/main.c b/src/main.c
index df6080d..f81d289 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,491 +1,51 @@
-#include "routing.h"
-#include "benc.h"
-#include "query.h"
+#include "proto.h"
#include "log.h"
-#include <errno.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <ctype.h>
-#include <assert.h>
-#include <stdlib.h>
-#include <stdint.h>
-#include <limits.h>
-#include <unistd.h>
-#include <stdbool.h>
-#include <string.h>
-#include <sys/socket.h>
-#include <netdb.h>
-#include <arpa/inet.h>
-#include <netdb.h>
-#include <sys/types.h>
-#include <stdio.h>
-
-#define MAX(a, b) \
- ({ \
- __typeof__ (a) _a = (a); \
- __typeof__ (b) _b = (b); \
- _a > _b ? _a : _b; \
- })
-
-#define MIN(a, b) \
- ({ \
- __typeof__ (a) _a = (a); \
- __typeof__ (b) _b = (b); \
- _a < _b ? _a : _b; \
- })
-
-
-void dbgl_id(struct nodeid* id) {
- for(uint8_t i = 0; i < 5; i++) {
- fprintf(stderr, "0x%08x ", id->inner[i]);
- }
- fprintf(stderr, "\n");
- fflush(stderr);
-}
-
-struct discovery {
- uint16_t port;
- struct nodeid expected_id;
-};
-
-int sockaddr_cmp(struct sockaddr* x, struct sockaddr* y) {
-#define CMP(a, b) \
- do { \
- typeof(a) cmp = a - b; \
- if(cmp != 0) return cmp; \
- } while(0)
- if (x->sa_family == AF_INET) {
- struct sockaddr_in *xin = (void*)x;
- struct sockaddr_in *yin = (void*)y;
-
- CMP(ntohl(xin->sin_addr.s_addr), ntohl(yin->sin_addr.s_addr));
- CMP(ntohs(xin->sin_port), ntohs(yin->sin_port));
- } else if (x->sa_family == AF_INET6) {
- struct sockaddr_in6 *xin6 = (void*)x, *yin6 = (void*)y;
- int r = memcmp(xin6->sin6_addr.s6_addr, yin6->sin6_addr.s6_addr, sizeof(xin6->sin6_addr.s6_addr));
- if (r != 0)
- return r;
- CMP(ntohs(xin6->sin6_port), ntohs(yin6->sin6_port));
- CMP(xin6->sin6_flowinfo, yin6->sin6_flowinfo);
- CMP(xin6->sin6_scope_id, yin6->sin6_scope_id);
- } else {
- err("Unsupported sa_family");
- abort();
- }
-
- return 0;
-};
-
-#define UNDEF_ADDR (struct in_addr){0xC0000200}
-#define MAX_DISC 32
-struct in_addr addrs[MAX_DISC];
-struct discovery pending_discover[MAX_DISC];
-
-typedef void (*cont)(struct nodeid* self, char* packet, size_t packet_len, int socket, struct sockaddr_in* remote, socklen_t remote_len);
-
-#define MAX_INFLIGHT 32
-bool reqalloc[MAX_INFLIGHT] = { false };
-struct {
- struct sockaddr addr;
- cont fun;
-} requestdata[MAX_INFLIGHT];
-
-bool alloc_req(uint16_t* reqId) {
- for(size_t i = 0; i < MAX_INFLIGHT; i++) {
- if(!reqalloc[i]) {
- reqalloc[i] = true;
- *reqId = i;
- return true;
- }
- }
- return false;
-}
-
-bool find_req(uint32_t transId, uint16_t* reqId) {
- *reqId = transId;
- return reqalloc[transId];
-}
-
-void getclient_response(struct nodeid* self, char* packet, size_t packet_len, int socket, struct sockaddr_in* remote, socklen_t remote_len);
-
-uint8_t rand_byte() {
- int limit = RAND_MAX - (RAND_MAX % UINT8_MAX);
- int val;
- while((val = rand()) > limit);
-
- return val;
-}
-
-int send_ping(struct nodeid* self, const int sfd, const struct sockaddr* dest_addr, socklen_t dest_len) {
- // Generate a random target
- struct nodeid target;
- for(uint8_t *target_byte = (uint8_t*)&target; target_byte < ((uint8_t*)&target)+sizeof(target); target_byte++) {
- *target_byte = rand_byte();
- }
-
- uint16_t reqId;
- if(!alloc_req(&reqId)) {
- return ENOBUFS;
- }
- char buff[128];
- size_t i = 0;
-
- dbg("Allocating request %d", reqId);
- requestdata[reqId].fun = &getclient_response;
- requestdata[reqId].addr = *dest_addr;
-
- int rc = snprintf(buff+i, 128-i, "d1:ad2:id20:");
- if(rc < 0)
- return EPERM;
- i += rc;
- memcpy(buff+i, self, sizeof(struct nodeid));
- i += sizeof(struct nodeid);
- rc = snprintf(buff+i, 128-i, "6:target20:");
- if(rc < 0)
- return EPERM;
- i += rc;
- memcpy(buff+i, &target, sizeof(struct nodeid));
- i += sizeof(struct nodeid);
- rc = snprintf(buff+i, 128-i, "e1:q9:find_node1:t%d:%d1:y1:qe", (reqId/10)+1, reqId);
- if(rc < 0)
- return EPERM;
- i += rc;
-
- //now reply the client with the same data
- rc = sendto(sfd, buff, i, 0, dest_addr, dest_len);
- if (rc == -1) {
- return EPERM; // Operation not permitted is used as the default "generic" error
- }
-
- return 0;
-}
-
-void getclient_response(struct nodeid* self, char* packet, size_t packet_len, int socket, struct sockaddr_in* remote, socklen_t remote_len) {
- struct benc_node stream[256];
- struct bcursor bcursor;
- bcur_open(&bcursor, packet, packet+packet_len, stream, 256);
-
- if(bcursor.end - bcursor.readhead <= 0) {
- err("Reponse too short");
- exit(EXIT_FAILURE);
- }
-
- struct nodeid id;
- uint8_t nodes_len;
- struct nodeid nodes[8];
- struct in_addr ips[8];
- uint16_t ports[8];
-
-
- // Read the payload
- {
- // Check that we have a dict
- if(bcursor.readhead->type != BNT_DICT) {
- err("Response is not a dict");
- exit(EXIT_FAILURE);
- }
- bcur_next(&bcursor, 1);
-
- bcur_find_key(&bcursor, (const enum benc_nodetype[]){BNT_STRING}, (const char*[]){"r"}, (const size_t[]){1}, 1);
- // Skip the key
- bcur_next(&bcursor, 1);
-
- if(bcursor.readhead->type != BNT_DICT) {
- err("Wrong value type for response");
- exit(EXIT_FAILURE);
- }
-
- // Skip the dict element
- bcur_next(&bcursor, 1);
-
- while(bcursor.readhead->type != BNT_END) {
- switch(bcur_find_key(&bcursor, (const enum benc_nodetype[]){BNT_STRING, BNT_STRING}, (const char*[]){"nodes", "id"}, (const size_t[]){5, 2}, 2)) {
- case 0:
- // Skip the key
- bcur_next(&bcursor, 1);
-
- if(bcursor.readhead->type != BNT_STRING) {
- err("Wrong value type for response");
- exit(EXIT_FAILURE);
- }
-
- if((bcursor.readhead->size % 26) != 0) {
- err("get_nodes call returned an incorrect nodes array");
- exit(EXIT_FAILURE);
- }
-
- nodes_len = MIN(bcursor.readhead->size/26, 8);
- dbg("We have %d (%d/26) nodes", nodes_len, bcursor.readhead->size);
- for(int i = 0; i < nodes_len; i++) {
- memcpy(nodes+i, bcursor.readhead->loc+(26*i), 20);
- memcpy(ips+i, bcursor.readhead->loc+(26*i)+20, 4);
- memcpy(ports+i, bcursor.readhead->loc+(26*i)+24, 2);
- }
-
- // Skip the value
- bcur_next(&bcursor, 1);
- break;
- case 1:
- // Skip the key
- bcur_next(&bcursor, 1);
-
- if(bcursor.readhead->type != BNT_STRING) {
- err("Wrong value type for response");
- exit(EXIT_FAILURE);
- }
-
- if(bcursor.readhead->size != 20) {
- err("remote node id was not 20 bytes long");
- exit(EXIT_FAILURE);
- }
-
- memcpy(&id, bcursor.readhead->loc, 20);
-
- // Skip the value
- bcur_next(&bcursor, 1);
- break;
- }
+void flush_messages(int sfd, struct message* cursor, const struct message* const end) {
+ dbg("Flushing %ld pending messages", end - cursor);
+ for(; cursor < end; cursor++) {
+ //now reply the client with the same data
+ int rc = sendto(sfd, cursor->payload, cursor->payload_len, 0, (const struct sockaddr*)&cursor->dest, cursor->dest_len);
+ if (rc < 0) {
+ fatal("Failed to send message");
}
}
-
- // Print the candidates
- for(uint8_t i = 0; i < nodes_len; i++) {
- dbgl_id(&nodes[i]);
- printf("Candidate %s:%d\n", inet_ntoa(ips[i]), ntohs(ports[i]));
-
- struct sockaddr_in dest = {
- .sin_family = AF_INET,
- .sin_addr = ips[i],
- .sin_port = ports[i],
- };
-
- if(routing_interested(&nodes[i])) {
- int rc = send_ping(self, socket, (struct sockaddr*)&dest, sizeof(struct sockaddr_in));
- if(rc != 0) {
- err("send_ping failed %d", rc);
- }
- } else {
- dbg("Not interested in node");
- }
- }
-
- struct entry* entry;
- routing_offer(&id, &entry);
}
-enum commandType {
- CT_QUERY,
- CT_RESPONSE,
- CT_ERROR,
-};
-
int main(int argc, char** argv) {
- for(int i = 0; i < MAX_DISC; i++) {
- // 192.0.2.0
- addrs[i] = UNDEF_ADDR;
- }
-
- struct nodeid self = {.inner={0x0034048f, 0x08000020, 0x00888880, 0x02008460, 0x0ab00521}};
- routing_init(&self);
- dbgl_id(&self);
-
- int sfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
- if(sfd == -1) {
- err("Failed creating socket");
- exit(1);
- }
- struct sockaddr_in bindAddr = {0};
- bindAddr.sin_family = AF_INET;
- bindAddr.sin_port = htons(6881);
- bindAddr.sin_addr.s_addr = htonl(INADDR_ANY);
- bind(sfd, (struct sockaddr*)&bindAddr, sizeof(struct sockaddr_in));
-
- struct addrinfo hints = {0};
- hints.ai_family = AF_INET;
- hints.ai_socktype = SOCK_DGRAM;
- hints.ai_protocol = IPPROTO_UDP;
- hints.ai_flags = AI_NUMERICSERV;
+ struct message outbuff[10] = {0};
- struct addrinfo* res;
- int rc = getaddrinfo("router.bittorrent.com", "6881", &hints, &res);
- if(rc != 0) {
- err("Failed getting the bootstrap ip: %s", gai_strerror(rc));
- exit(EXIT_FAILURE);
- }
-
- for(struct addrinfo* cur = res; cur != NULL; cur = cur->ai_next) {
- char buff[128];
- inet_ntop(cur->ai_family, &((struct sockaddr_in*)cur->ai_addr)->sin_addr, buff, 128);
- dbg("IP %s", buff);
-
- /* size_t i = 0; */
- /* int rc = snprintf(buff+i, 128-i, "d1:ad2:id20:"); */
- /* i += rc; */
- /* memcpy(buff+i, &self, sizeof(struct nodeid)); */
- /* i += sizeof(struct nodeid); */
- /* rc = snprintf(buff+i, 128-i, "e1:q4:ping1:t2:ab1:y1:qe"); */
- /* i += rc; */
+ struct dht dht;
+ dht.self = (struct nodeid){.inner={0x0034048f, 0x08000020, 0x00888880, 0x02008460, 0x0ab00521}};
+ struct message* message_cursor = outbuff;
+ proto_begin(&dht, &message_cursor, outbuff+10);
+ flush_messages(dht.sfd, outbuff, message_cursor);
- send_ping(&self, sfd, cur->ai_addr, cur->ai_addrlen);
- }
-
- freeaddrinfo(res);
- //keep listening for data
- while(1) {
+ int rc = 0;
+ while(rc == 0) {
char buff[2049];
printf("Waiting for data...");
fflush(stdout);
-
- //try to receive some data, this is a blocking call
- ssize_t recv_len;
- struct sockaddr_in remote;
+
+ // Try to receive some data, this is a blocking call
+ struct sockaddr_storage remote;
socklen_t remote_len = sizeof(remote);
- if ((recv_len = recvfrom(sfd, buff, 2048, 0, (struct sockaddr *)&remote, &remote_len)) == -1) {
- fatal("recvfrom failed");
- }
- if(recv_len >= 2048) {
- fatal("Recv buffer too small");
+ ssize_t recv_len = recvfrom(dht.sfd, buff, 2048, 0, (struct sockaddr *)&remote, &remote_len);
+ if(recv_len == -1) {
+ fatal("RECV failed");
+ } else if(recv_len >= 2048) {
+ fatal("Receive buffer too small");
}
// Null terminate the packet
buff[recv_len] = '\0';
- printf("Received packet from %s:%d\n", inet_ntoa(remote.sin_addr), ntohs(remote.sin_port));
-
- struct bcursor bcursor;
- struct benc_node stream[256];
- bcur_open(&bcursor, buff, buff+recv_len, stream, 256);
- benc_print(bcursor.readhead, bcursor.end - bcursor.readhead);
-
- if(bcursor.readhead->type != BNT_DICT) {
- fatal("First value is not a dict");
- }
- bcur_next(&bcursor, 1);
-
- bool discard = false;
- enum commandType type;
- bool transaction_set = false;
- char transaction[64];
- size_t transaction_len;
- bool query_set = false;
- char query[64];
- size_t query_len;
- while(bcursor.readhead->type != BNT_END) {
- switch(bcur_find_key(&bcursor, (const enum benc_nodetype[]){BNT_STRING, BNT_STRING, BNT_STRING}, (const char*[]){"y", "t", "q"}, (const size_t[]){1, 1, 1}, 3)) {
- case 0:
- // Skip the key
- bcur_next(&bcursor, 1);
- if(*bcursor.readhead->loc == 'r') {
- type = CT_RESPONSE;
- } else if(*bcursor.readhead->loc == 'q') {
- type = CT_QUERY;
- } else if(*bcursor.readhead->loc == 'e') {
- type = CT_ERROR;
- } else {
- fatal("Unknown command type %c", *bcursor.readhead->loc);
- }
- // Skip the value
- bcur_next(&bcursor, 1);
- break;
- case 1: {
- // Skip the key
- bcur_next(&bcursor, 1);
- if(bcursor.readhead->size > 64-1)
- fatal("Transaction string too long");
-
- transaction_set = true;
- transaction_len = bcursor.readhead->size;
- memcpy(transaction, bcursor.readhead->loc, transaction_len);
- transaction[transaction_len] = '\0';
-
- // Skip the value
- bcur_next(&bcursor, 1);
- break;
- }
- case 2: {
- bcur_next(&bcursor, 1);
- query_set = true;
- query_len = bcursor.readhead->size;
- memcpy(query, bcursor.readhead->loc, query_len);
- query[query_len] = '\0';
- bcur_next(&bcursor, 1);
- }
- }
- }
-
- if(discard)
- continue;
-
- if(type == CT_RESPONSE) {
- uint32_t transaction_number;
-
- if(!transaction_set)
- fatal("No transaction in response");
-
- // Temporary null terminate the string to parse the number without a copy
- char* end;
- transaction_number = strtol(transaction, &end, 10);
-
- if(end != transaction+transaction_len) {
- fatal("DISCARD: Transaction id is not a number %.*s", transaction_len, transaction);
- }
-
- uint16_t reqId;
- if(!find_req(transaction_number, &reqId)) {
- dbg("DISCARD: unknown transaction id %d", transaction);
- continue;
- }
- dbg("Transaction id matches request %d", reqId);
-
- if(sockaddr_cmp(&requestdata[reqId].addr, (struct sockaddr*)&remote) != 0) {
- fatal("Unexpected IP for valid transaction");
- }
-
- requestdata[reqId].fun(&self, buff, recv_len, sfd, &remote, remote_len);
-
- reqalloc[reqId] = false;
- } else if(type == CT_QUERY) { // Must be a query
- if(!query_set)
- fatal("No query function in query request");
- if(!transaction_set)
- fatal("No transaction in request");
-
- assert(strlen(query) == query_len);
-
- char response[1024];
- char* end = response+sizeof(response)-1;
- char* cursor = response;
-
- int rc = snprintf(cursor, end-cursor , "d1:t%ld:", transaction_len);
- if(rc < 0)
- return EPERM;
- cursor += rc;
- memcpy(cursor, transaction, transaction_len);
- cursor += transaction_len;
- rc = snprintf(cursor, end-cursor, "1:y1:r1:r");
- if(rc < 0)
- return EPERM;
- cursor += rc;
-
- rc = handle_request(&self, query, buff, recv_len, &cursor, end-cursor-1);
- if(rc != 0) fatal("Error handling request");
-
- rc = snprintf(cursor, end-cursor, "e");
- if(rc < 0)
- return EPERM;
- cursor += rc;
-
- //now reply the client with the same data
- rc = sendto(sfd, buff, cursor-response, 0, (const struct sockaddr*)&remote, remote_len);
- if (rc == -1) {
- return EPERM; // Operation not permitted is used as the default "generic" error
- }
-
- }
+ struct message* message_cursor = outbuff;
+ rc = proto_run(&dht, buff, recv_len, (struct sockaddr_in*)&remote, remote_len, &message_cursor, outbuff+10);
+ flush_messages(dht.sfd, outbuff, message_cursor);
}
- close(sfd);
+ proto_end(&dht);
- return 0;
+ return rc;
}
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