diff --git a/.gitignore b/.gitignore index e660fd9..752c478 100644 --- a/.gitignore +++ b/.gitignore @@ -1 +1,4 @@ bin/ +out/ +net +test diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..95a70e1 --- /dev/null +++ b/Makefile @@ -0,0 +1,15 @@ + + +all: bin/net bin/test + + +bin/net: net.c + mkdir -pv bin + gcc -o bin/net net.c + +bin/test: test.c + mkdir -pv bin + gcc -o bin/test test.c + +clean: + rm -rf bin diff --git a/net.c b/net.c new file mode 100644 index 0000000..d1d7aed --- /dev/null +++ b/net.c @@ -0,0 +1,93 @@ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define PORT "4711" + +void *get_in_addr(struct sockaddr *sa) +{ + if (sa->sa_family == AF_INET) { + return &(((struct sockaddr_in*)sa)->sin_addr); + } + + return &(((struct sockaddr_in6*)sa)->sin6_addr); +} + +int main (int argc, char **argv) { + + struct addrinfo hints, *servinfo; + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = AF_INET; // IPv4 + hints.ai_socktype = SOCK_DGRAM; // UDP + hints.ai_flags = AI_PASSIVE; + + int rv; + if ((rv = getaddrinfo(NULL, PORT, &hints, &servinfo)) != 0) { + fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv)); + return 1; + } + + printf("got local address\n"); + + struct addrinfo *info; + int sockfd; + char s[INET6_ADDRSTRLEN]; + for (info = servinfo; info != NULL; info = info->ai_next) { +/* if (info->ai_addr) { + struct sockaddr_in* p = (struct sockaddr_in *)info->ai_addr; + inet_ntop(p->sin_family, &p->sin_addr, s, INET6_ADDRSTRLEN); + printf(" %d: %s\n", info->ai_addr->sa_family, s); + } +*/ + + if ((sockfd = socket(info->ai_family, info->ai_socktype, info->ai_protocol)) == -1) { + perror("sock"); + continue; + } + + if (bind(sockfd, info->ai_addr, info->ai_addrlen) == -1) { + perror("bind"); + continue; + } + + break; + } + if (!info) { + fprintf(stderr, "unbound\n"); + return 2; + } + printf("check!\n"); + + freeaddrinfo(servinfo); // free whole list + + struct sockaddr_storage their_addr; + socklen_t addr_len = sizeof their_addr; + int numbytes; + char buf[10000]; + do { + if ((numbytes = recvfrom(sockfd, buf, 9999 , 0, (struct sockaddr *)&their_addr, &addr_len)) == -1) { + perror("recvfrom"); + exit(1); + } + + printf("listener: got packet from %s\n", inet_ntop(their_addr.ss_family, get_in_addr((struct sockaddr *)&their_addr), s, sizeof s)); + printf("listener: packet is %d bytes long\n", numbytes); + buf[numbytes] = '\0'; + printf("listener: packet contains \"%s\"\n", buf); + } while (strncmp(buf, "exit", 10000)); + + + close(sockfd); + + return 0; +} + diff --git a/test.c b/test.c new file mode 100644 index 0000000..4dcb391 --- /dev/null +++ b/test.c @@ -0,0 +1,67 @@ +/* +** talker.c -- a datagram "client" demo +*/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define SERVERPORT "4711" // the port users will be connecting to + +int main(int argc, char *argv[]) +{ + int sockfd; + struct addrinfo hints, *servinfo, *p; + int rv; + int numbytes; + + if (argc != 3) { + fprintf(stderr,"usage: talker hostname message\n"); + exit(1); + } + + memset(&hints, 0, sizeof hints); + hints.ai_family = AF_UNSPEC; + hints.ai_socktype = SOCK_DGRAM; + + if ((rv = getaddrinfo(argv[1], SERVERPORT, &hints, &servinfo)) != 0) { + fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv)); + return 1; + } + + // loop through all the results and make a socket + for(p = servinfo; p != NULL; p = p->ai_next) { + if ((sockfd = socket(p->ai_family, p->ai_socktype, + p->ai_protocol)) == -1) { + perror("talker: socket"); + continue; + } + + break; + } + + if (p == NULL) { + fprintf(stderr, "talker: failed to bind socket\n"); + return 2; + } + + if ((numbytes = sendto(sockfd, argv[2], strlen(argv[2]), 0, + p->ai_addr, p->ai_addrlen)) == -1) { + perror("talker: sendto"); + exit(1); + } + + freeaddrinfo(servinfo); + + printf("talker: sent %d bytes to %s\n", numbytes, argv[1]); + close(sockfd); + + return 0; +}