83 lines
2.7 KiB
C
83 lines
2.7 KiB
C
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <string.h>
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#include <sinkStruct.h>
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#include <logging.h>
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#include <libconfig.h>
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int receiver(config_t *cfg) {
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config_setting_t *devicesConfig = config_lookup(cfg, "devices");
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if (devicesConfig == NULL) {
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logmsg(LOG_ERR, "receiver: no devices configuration found");
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return -1;
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}
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int sockfd;
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struct sockaddr_in servaddr, cliaddr;
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socklen_t cliaddrlen = sizeof(cliaddr);
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sockfd = socket(AF_INET, SOCK_DGRAM, 0);
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memset(&servaddr, 0, sizeof(servaddr));
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servaddr.sin_family = AF_INET;
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servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
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servaddr.sin_port = htons(20169);
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bind(sockfd, (const struct sockaddr *) &servaddr, sizeof(servaddr));
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t_minuteBuffer buf;
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while (1) {
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int n = recvfrom(sockfd, buf.b, sizeof(buf.b), MSG_TRUNC,
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(struct sockaddr *) &cliaddr, &cliaddrlen);
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logmsg(LOG_INFO, "received %d octets from %04x", n, cliaddr.sin_addr.s_addr);
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if (n != sizeof(buf.b)) {
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logmsg(LOG_INFO, "Illegal packet size: %d", n);
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continue;
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}
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config_setting_t *deviceConfig = config_lookup(devicesConfig, buf.s.deviceId);
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if (deviceConfig == NULL) {
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logmsg(LOG_INFO, "Unknown device: %s", buf.s.deviceId);
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continue;
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}
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const char *sharedSecret;
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if (! config_setting_lookup_string(deviceConfig, "sharedSecret", &sharedSecret)) {
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logmsg(LOG_ERR, "No sharedsecret configured for device %s", buf.s.deviceId);
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continue;
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}
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if (strlen(sharedSecret) > SHA256_BLOCK_SIZE) {
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logmsg(LOG_ERR, "Configured sharedsecret for device %s is too long", buf.s.deviceId);
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continue;
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}
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uint8_t receivedHash[SHA256_BLOCK_SIZE];
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memcpy(receivedHash, buf.s.hash, SHA256_BLOCK_SIZE);
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memcpy(buf.s.hash, sharedSecret, SHA256_BLOCK_SIZE);
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SHA256_CTX ctx;
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uint8_t calculatedHash[SHA256_BLOCK_SIZE];
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sha256_init(&ctx);
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sha256_update(&ctx, buf.b, sizeof(buf.b));
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sha256_final(&ctx, calculatedHash);
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if (memcmp(receivedHash, calculatedHash, SHA256_BLOCK_SIZE) != 0) {
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logmsg(LOG_INFO, "Invalid hash in msg for device %s", buf.s.deviceId);
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continue;
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}
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logmsg(LOG_INFO, "DeviceId: %s", buf.s.deviceId);
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logmsg(LOG_INFO, "Location: %s", buf.s.location);
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for (uint8_t j = 0; j < SECONDS_PER_MINUTE; j++) {
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logmsg(LOG_INFO, "Time: %lu, Frequency: %u", buf.s.events[j].timestamp, buf.s.events[j].frequency);
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}
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}
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return 0;
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}
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