diff options
Diffstat (limited to 'util_ack/src/util_ack.c')
| -rw-r--r-- | util_ack/src/util_ack.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/util_ack/src/util_ack.c b/util_ack/src/util_ack.c new file mode 100644 index 0000000..7acd32e --- /dev/null +++ b/util_ack/src/util_ack.c @@ -0,0 +1,193 @@ +/* + / _____) _ | | +( (____ _____ ____ _| |_ _____ ____| |__ + \____ \| ___ | (_ _) ___ |/ ___) _ \ + _____) ) ____| | | || |_| ____( (___| | | | +(______/|_____)_|_|_| \__)_____)\____)_| |_| + (C)2013 Semtech-Cycleo + +Description: + Network sink, receives UDP packets and sends an acknowledge + +License: Revised BSD License, see LICENSE.TXT file include in the project +Maintainer: Sylvain Miermont +*/ + + +/* -------------------------------------------------------------------------- */ +/* --- DEPENDANCIES --------------------------------------------------------- */ + +/* fix an issue between POSIX and C99 */ +#if __STDC_VERSION__ >= 199901L + #define _XOPEN_SOURCE 600 +#else + #define _XOPEN_SOURCE 500 +#endif + +#include <stdint.h> /* C99 types */ +#include <stdio.h> /* printf, fprintf, sprintf, fopen, fputs */ +#include <unistd.h> /* usleep */ + +#include <string.h> /* memset */ +#include <time.h> /* time, clock_gettime, strftime, gmtime, clock_nanosleep*/ +#include <stdlib.h> /* atoi, exit */ +#include <errno.h> /* error messages */ + +#include <sys/socket.h> /* socket specific definitions */ +#include <netinet/in.h> /* INET constants and stuff */ +#include <arpa/inet.h> /* IP address conversion stuff */ +#include <netdb.h> /* gai_strerror */ + +/* -------------------------------------------------------------------------- */ +/* --- PRIVATE MACROS ------------------------------------------------------- */ + +#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) +#define STRINGIFY(x) #x +#define STR(x) STRINGIFY(x) +#define MSG(args...) fprintf(stderr, args) /* message that is destined to the user */ + +/* -------------------------------------------------------------------------- */ +/* --- PRIVATE CONSTANTS ---------------------------------------------------- */ + +#define PROTOCOL_VERSION 2 + +#define PKT_PUSH_DATA 0 +#define PKT_PUSH_ACK 1 +#define PKT_PULL_DATA 2 +#define PKT_PULL_RESP 3 +#define PKT_PULL_ACK 4 + +/* -------------------------------------------------------------------------- */ +/* --- MAIN FUNCTION -------------------------------------------------------- */ + +int main(int argc, char **argv) +{ + int i; /* loop variable and temporary variable for return value */ + + /* server socket creation */ + int sock; /* socket file descriptor */ + struct addrinfo hints; + struct addrinfo *result; /* store result of getaddrinfo */ + struct addrinfo *q; /* pointer to move into *result data */ + char host_name[64]; + char port_name[64]; + + /* variables for receiving and sending packets */ + struct sockaddr_storage dist_addr; + socklen_t addr_len = sizeof dist_addr; + uint8_t databuf[4096]; + int byte_nb; + + /* variables for protocol management */ + uint32_t raw_mac_h; /* Most Significant Nibble, network order */ + uint32_t raw_mac_l; /* Least Significant Nibble, network order */ + uint64_t gw_mac; /* MAC address of the client (gateway) */ + uint8_t ack_command; + + /* check if port number was passed as parameter */ + if (argc != 2) { + MSG("Usage: util_ack <port number>\n"); + exit(EXIT_FAILURE); + } + + /* prepare hints to open network sockets */ + memset(&hints, 0, sizeof hints); + hints.ai_family = AF_UNSPEC; /* should handle IP v4 or v6 automatically */ + hints.ai_socktype = SOCK_DGRAM; + hints.ai_flags = AI_PASSIVE; /* will assign local IP automatically */ + + /* look for address */ + i = getaddrinfo(NULL, argv[1], &hints, &result); + if (i != 0) { + MSG("ERROR: getaddrinfo returned %s\n", gai_strerror(i)); + exit(EXIT_FAILURE); + } + + /* try to open socket and bind it */ + for (q=result; q!=NULL; q=q->ai_next) { + sock = socket(q->ai_family, q->ai_socktype,q->ai_protocol); + if (sock == -1) { + continue; /* socket failed, try next field */ + } else { + i = bind(sock, q->ai_addr, q->ai_addrlen); + if (i == -1) { + shutdown(sock, SHUT_RDWR); + continue; /* bind failed, try next field */ + } else { + break; /* success, get out of loop */ + } + } + } + if (q == NULL) { + MSG("ERROR: failed to open socket or to bind to it\n"); + i = 1; + for (q=result; q!=NULL; q=q->ai_next) { + getnameinfo(q->ai_addr, q->ai_addrlen, host_name, sizeof host_name, port_name, sizeof port_name, NI_NUMERICHOST); + MSG("INFO: result %i host:%s service:%s\n", i, host_name, port_name); + ++i; + } + exit(EXIT_FAILURE); + } + MSG("INFO: util_ack listening on port %s\n", argv[1]); + freeaddrinfo(result); + + while (1) { + /* wait to receive a packet */ + byte_nb = recvfrom(sock, databuf, sizeof databuf, 0, (struct sockaddr *)&dist_addr, &addr_len); + if (byte_nb == -1) { + MSG("ERROR: recvfrom returned %s \n", strerror(errno)); + exit(EXIT_FAILURE); + } + + /* display info about the sender */ + i = getnameinfo((struct sockaddr *)&dist_addr, addr_len, host_name, sizeof host_name, port_name, sizeof port_name, NI_NUMERICHOST); + if (i == -1) { + MSG("ERROR: getnameinfo returned %s \n", gai_strerror(i)); + exit(EXIT_FAILURE); + } + printf(" -> pkt in , host %s (port %s), %i bytes", host_name, port_name, byte_nb); + + /* check and parse the payload */ + if (byte_nb < 12) { /* not enough bytes for packet from gateway */ + printf(" (too short for GW <-> MAC protocol)\n"); + continue; + } + /* don't touch the token in position 1-2, it will be sent back "as is" for acknowledgement */ + if (databuf[0] != PROTOCOL_VERSION) { /* check protocol version number */ + printf(", invalid version %u\n", databuf[0]); + continue; + } + raw_mac_h = *((uint32_t *)(databuf+4)); + raw_mac_l = *((uint32_t *)(databuf+8)); + gw_mac = ((uint64_t)ntohl(raw_mac_h) << 32) + (uint64_t)ntohl(raw_mac_l); + + /* interpret gateway command */ + switch (databuf[3]) { + case PKT_PUSH_DATA: + printf(", PUSH_DATA from gateway 0x%08X%08X\n", (uint32_t)(gw_mac >> 32), (uint32_t)(gw_mac & 0xFFFFFFFF)); + ack_command = PKT_PUSH_ACK; + printf("<- pkt out, PUSH_ACK for host %s (port %s)", host_name, port_name); + break; + case PKT_PULL_DATA: + printf(", PULL_DATA from gateway 0x%08X%08X\n", (uint32_t)(gw_mac >> 32), (uint32_t)(gw_mac & 0xFFFFFFFF)); + ack_command = PKT_PULL_ACK; + printf("<- pkt out, PULL_ACK for host %s (port %s)", host_name, port_name); + break; + default: + printf(", unexpected command %u\n", databuf[3]); + continue; + } + + /* add some artificial latency */ + usleep(30000); /* 30 ms */ + + /* send acknowledge and check return value */ + databuf[3] = ack_command; + byte_nb = sendto(sock, (void *)databuf, 4, 0, (struct sockaddr *)&dist_addr, addr_len); + if (byte_nb == -1) { + printf(", send error:%s\n", strerror(errno)); + } else { + printf(", %i bytes sent\n", byte_nb); + } + } +} |