#pragma once
#include <arpa/inet.h>
#include <sys/socket.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <sys/select.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <netdb.h>
#include <string.h>
#include <sys/time.h>
#define ERR_INET_ADDR "0.9.9.0"
#define TCPC_READ_BUF 1024 /* en kilobajt */
#define TCPC_RESOLVE_RETRIES 12
union ip_conv {
unsigned char c[4];
struct in_addr in;
};
struct in_addr hostname_to_ip (const char * hostname) {
struct hostent *he; /* STATIC! */
union ip_conv ipconverter;
struct in_addr *error_addr = malloc(sizeof(struct in_addr));
/* int ret = */ inet_aton(ERR_INET_ADDR, error_addr); /* TODO: chek for err */
if ( (he = gethostbyname(hostname)) == NULL ) {
herror("gethostbyname");
return *error_addr;
} else {
memcpy(ipconverter.c, he->h_addr, 4); // fuck yes now it works
// fprintf(stderr, "debug: %s\n", inet_ntoa(ipconverter.in));
return ipconverter.in;
}
}
int spawn_conn (const char * address, const int port) {
int ret;
int conn_fd;
struct sockaddr_in server_addr = { 0 };
unsigned short int r /* etries */= TCPC_RESOLVE_RETRIES;
server_addr.sin_family = AF_INET;
server_addr.sin_port = htons(port);
ret = inet_pton(AF_INET, address, &server_addr.sin_addr);
if (ret != 1) {
if (ret == -1)
perror("inet_pton");
fprintf(stderr, "%s is not an IPv4, trying to resolve ...\n", address);
struct in_addr ret; /* zakaj sem tudi to poimenoval ret!? sicer dela. */
struct in_addr error_addr;
retry_resolve:
ret = hostname_to_ip(address);
inet_aton(ERR_INET_ADDR, &error_addr);
if (memcmp(&ret, &error_addr, 4) == 0) {
fprintf(stderr, "failed to resolve-%s.\n", r ? "retrying" : "failing");
if (r--)
goto retry_resolve;
return -1;
}
server_addr.sin_addr = ret;
fprintf(stderr, "resolved to %s.\n", inet_ntoa(server_addr.sin_addr));
}
conn_fd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
if(conn_fd == -1) {
perror("socket");
return -1;
}
ret = connect(conn_fd, (struct sockaddr*)&server_addr, sizeof(server_addr));
if (ret == 1) {
perror("connect");
return -1;
}
return conn_fd;
}
int kill_conn (int conn_fd) {
int ret = shutdown(conn_fd, SHUT_RDWR); // preprečimo tako read kot write.:wq
if (ret == -1) {
perror("shutdown");
return -1;
}
ret = close(conn_fd);
if (ret == -1) {
perror("close");
return -1;
}
return 0;
}
int read_until(int conn_fd, FILE * out, unsigned int timeout, const char * ma,
unsigned long long int max_bytes) {
int ret = 0;
unsigned int match = 0;
struct timeval start, stop;
gettimeofday(&start, NULL);
char c[TCPC_READ_BUF+1];
while (1) {
ret = read(conn_fd, c, ma ? 1 : TCPC_READ_BUF);
if (ret == -1) {
if (errno == EWOULDBLOCK) {
} else {
fprintf(stderr, "%s@" __FILE__ ":%d read(): %s%d\n", __func__, __LINE__, strerror(errno), ret);
return 1;
}
} else if (ret == 0) { /* strežnik ni poslal ničesar */
fprintf(stderr, "%s@" __FILE__ ":%d read(): server closed connection\n", __func__, __LINE__);
return 0;
} else {
fwrite(c, ret, 1, out);
max_bytes--;
if (max_bytes <= 0) {
return 0;
}
if (ma != NULL) {
if (ma[match] == c[0]) {
match++;
if (match == strlen(ma)) {
return 0;
}
} else {
match = 0;
}
}
}
gettimeofday(&stop, NULL);
if (stop.tv_sec - start.tv_sec > timeout) {
fprintf(stderr, "%s@" __FILE__ ":%d E_TIMEOUT %ld-%ld>%u\n", __func__,
__LINE__, stop.tv_sec, start.tv_sec, timeout);
return 2;
}
}
return 0;
}
int sync_write(int conn_fd, const char * req, int len, unsigned int timeout) {
int ret = write(conn_fd, req, len);
struct timeval start, stop;
gettimeofday(&start, NULL);
if (ret == -1) {
if (errno == EBADF) {
fprintf(stderr, "tcp.c: sync_write: write EBADF: %s\n", strerror(errno));
return -1;
}
while (errno == EWOULDBLOCK) {
ret = write(conn_fd, req, len);
if(ret != -1) {
return 0;
}
gettimeofday(&stop, NULL);
if (stop.tv_sec - start.tv_sec > timeout) {
fprintf(stderr, "tcp.c: sync_write: E_TIMEOUT %ld-%ld>%u\n",
start.tv_sec, stop.tv_sec, timeout);
return -2;
}
}
}
return 0;
}
#if __INCLUDE_LEVEL__ == 0
static volatile int sigint = 0;
void intHandler(int sig) {
signal(sig, SIG_IGN);
if (sig == SIGINT)
sigint++;
if (sigint >= 3) // some people smash CtrlC multiple times to force quit!
exit(130);
signal(sig, intHandler);
}
int main (int argc, char ** argv) {
if (argc != 1+2) {
fprintf(stderr, "usage: %s ip.v4.ad.dr port\n", argv[0]);
return 1;
}
signal(SIGINT, intHandler);
#define ADDRESS_ARG argv[1]
#define PORT_ARG argv[2]
int conn_fd = spawn_conn(ADDRESS_ARG, atoi(PORT_ARG));
if (conn_fd < 0) {
fprintf(stderr, "error connecting!\n");
return 2;
} else {
fprintf(stderr, "suc. conn with fd %d\n\n", conn_fd);
}
int buf = 0;
#define READ_MAX_SIZE 1024
char read_buf[READ_MAX_SIZE];
int i = 0;
char input;
fcntl(STDIN_FILENO, F_SETFL, fcntl(STDIN_FILENO, F_GETFL) | O_NONBLOCK);
while (1) {
if (sigint > 0) {
// fprintf(stderr, "\n" USERSTRING_EXIT_CONFIRM " (y/N)\n");
// char gotchar = getchar();
// if (gotchar == 'y' || gotchar == 'Y' || gotchar == 'd' ||
// gotchar == 'D' || gotchar == 'j' || gotchar == 'J') {
// kill_conn(conn_fd);
// return 0;
// }
if (kill_conn(conn_fd) == 0) {
fprintf(stderr, "\nconnection killed successfully, exiting ...\n");
} else {
fprintf(stderr, "\nconnection killing FAILED, exiting ...\n");
}
return 0;
}
buf = read(conn_fd, read_buf, READ_MAX_SIZE);
if (buf == -1 && errno != EWOULDBLOCK) {
fprintf(stderr, "\nerror reading from socket.\n");
if (kill_conn(conn_fd) != 0) {
fprintf(stderr, "\nerror killing socket\n");
return 3;
}
return 4;
}
if (buf == 0) {
fprintf(stderr, "\nserver closed socket\n");
if (kill_conn(conn_fd) != 0) {
fprintf(stderr, "\nerror killing socket\n");
return 5;
}
return 6;
}
if (errno == EWOULDBLOCK && buf == -1) {
// no data is on socket; sockets are non blocking.
} else {
buf = write(STDOUT_FILENO, read_buf, buf);
if(buf == -1) {
fprintf(stderr, "\nerror writing to stdout\n");
return 7;
}
}
buf = read(STDIN_FILENO, read_buf, READ_MAX_SIZE);
if (buf == -1 && errno != EWOULDBLOCK) {
fprintf(stderr, "\nerror reading from stdin\n");
return 8;
}
if (buf == 0) {
// fprintf(stderr, "\neof on stdin\n"); // that's okay
// return 9;
}
if (errno == EWOULDBLOCK && buf == -1) {
// no data in stdin
} else {
i = write(conn_fd, read_buf, buf);
if (i == -1) {
if(errno != EWOULDBLOCK) {
fprintf(stderr, "\nerror writing to socket\n");
if(kill_conn(conn_fd) != 0) {
fprintf(stderr, "\nerror killing connection\n");
return 10;
}
return 12;
} else {
while (i == -1) {
if (errno == EWOULDBLOCK) {
fprintf(stderr, "\nwrite to socket blocked, trying again\n");
i = write (conn_fd, read_buf, buf);
} else {
fprintf(stderr, "\nerror writing to socket\n");
if (kill_conn(conn_fd) != 0) {
fprintf(stderr, "\nerror killing connection\n");
return 13;
}
return 14;
}
}
}
}
}
buf = 0;
}
}
#endif
