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#ifdef __linux__
#define _POSIX_C_SOURCE 200809L
#define _DEFAULT_SOURCE
#endif
#include <stdlib.h>
#include <stdio.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <string.h>
#include <syslog.h>
#include <limits.h>
#include <errno.h>
#include <unistd.h>
#ifdef __FreeBSD__
#include <sys/param.h>
#endif
#include "handlers.h"
#include "packet.h"
#include "netascii.h"
nbd_opmode get_mode(char *mode) {
nbd_opmode opmode;
if (strncmp(mode, (char *)&"netascii", NBD_NBTPD_ARGS_MODE_MAX) == 0) {
opmode = NETASCII;
} else if (strncmp(mode, (char *)&"octet", NBD_NBTPD_ARGS_MODE_MAX) == 0) {
opmode = OCTET;
} else if (strncmp(mode, (char *)&"mail", NBD_NBTPD_ARGS_MODE_MAX) == 0) {
opmode = MAIL;
} else {
opmode = NOT_FOUND;
}
return opmode;
}
void *read_req_resp(void *args) {
char *fname = NULL, *wd = NULL, *buf = NULL, *rxb = NULL;
FILE *fp = NULL;
nbd_nbtpd_args *argptr = (nbd_nbtpd_args *)args;
syslog(LOG_DEBUG, "%s:%d is requesting file %s", inet_ntoa(argptr->client.sin_addr), ntohs(argptr->client.sin_port), argptr->path);
if (!is_netascii_str((char *)&argptr->path)) {
argptr->err = 1;
goto pre_socket;
}
fname = realpath((char *)&argptr->path, NULL);
if (fname == NULL) {
syslog(LOG_ERR, "unable to get real path: %s", strerror(errno));
argptr->err = 1;
goto pre_socket;
}
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* POSIX does not define what happens when getcwd() is given NULL. *
* This means that illumos libc and GNU libc both return a newly *
* malloc()'d string, while FreeBSD libc does not. Also, FreeBSD uses *
* constant MAXPATHLEN defined in <sys/param.h> rather than PATH_MAX. *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
#ifdef __FreeBSD__
wd = malloc(MAXPATHLEN);
if (wd == NULL) {
syslog(LOG_ERR, "unable to allocate PATH_MAX memory: %s", strerror(errno));
argptr->err = 0;
goto pre_socket;
}
if (getcwd(wd, MAXPATHLEN) == NULL) {
argptr->err = 0;
goto pre_socket;
}
#else
if ((wd = getcwd(NULL, PATH_MAX)) == NULL) {
argptr->err = 0;
goto pre_socket;
}
#endif
syslog(LOG_DEBUG, "cwd: %s :: realpath: %s", wd, fname);
if (strncmp(wd, fname, strlen(wd))) {
syslog(
LOG_ERR,
"%s:%d requested invalid file %s",
inet_ntoa(argptr->client.sin_addr),
ntohs(argptr->client.sin_port),
fname
);
argptr->err = 2;
goto pre_socket;
}
if (!is_netascii_str((char *)&(argptr->mode))) {
syslog(
LOG_ERR,
"%s:%d mode is invalid %s",
inet_ntoa(argptr->client.sin_addr),
ntohs(argptr->client.sin_port),
argptr->mode
);
argptr->err = 4;
goto pre_socket;
}
nbd_opmode opmode = get_mode((char *)&(argptr->mode));
if ((opmode != NETASCII) && (opmode != OCTET)) {
argptr->err = 4;
goto pre_socket;
}
fp = fopen(fname, "r");
if (fp == NULL) {
syslog(
LOG_ERR,
"failed to open file for reading: %s",
strerror(errno)
);
argptr->err = 2;
goto pre_socket;
}
buf = malloc(512);
rxb = malloc(256);
if (buf == NULL) {
syslog(
LOG_CRIT,
"failed to allocate memory: %s",
strerror(errno)
);
argptr->err = 0;
goto pre_socket;
}
int s = socket(AF_INET, SOCK_DGRAM, 0);
if (s <= 0) {
syslog(LOG_ERR, "unable to define socket: %s", strerror(errno));
goto cleanup;
}
struct timeval timeout = { 30, 0 };
if (setsockopt(s, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout)) < 0) {
syslog(LOG_ERR, "unable to set socket timeout: %s", strerror(errno));
goto socket_clean;
}
if (connect(s, (struct sockaddr *)&(argptr->client), sizeof(struct sockaddr)) < 0) {
syslog(
LOG_ERR,
"unable to connect to client %s: %s",
inet_ntoa(argptr->client.sin_addr),
strerror(errno)
);
goto socket_clean;
}
uint8_t rxon = 0, lon = 1;
uint16_t bnum = 0;
while (lon) {
memset(buf, '\0', 512);
uint8_t verif = 0;
uint8_t vcount = 0;
size_t num_read = fread(buf, 1, 512, fp);
if (((num_read < 512) && (!feof(fp))) || (vcount > 5)) {
//TODO: error response function!
}
char *packet = nbd_tftp_ser_data_from_parts(++bnum, buf, num_read);
while (!verif) {
syslog(LOG_DEBUG, "sending block number %d to %s:%d",
bnum,
inet_ntoa(argptr->client.sin_addr),
htons(argptr->client.sin_port)
);
if (send(s, packet, num_read + 4, 0) < 0) {
syslog(
LOG_ERR,
"unable to send data to %s: %s",
inet_ntoa(argptr->client.sin_addr),
strerror(errno)
);
continue;
}
rxon = 1;
uint8_t rxcount = 0;
while (rxon) {
syslog(LOG_DEBUG, "waiting for ack %d from %s:%d",
bnum,
inet_ntoa(argptr->client.sin_addr),
htons(argptr->client.sin_port)
);
memset(rxb, '\0', 256);
ssize_t rcv = recv(s, rxb, 256, 0);
syslog(LOG_DEBUG, "recv'd %ld bytes from %s:%d",
rcv,
inet_ntoa(argptr->client.sin_addr),
htons(argptr->client.sin_port)
);
if (rcv == 4) {
nbd_tftp_packet_ack ack = nbd_tftp_de_ack(rxb, rcv);
syslog(LOG_DEBUG, "%s:%d ack'd with block number: %d (expect %d)",
inet_ntoa(argptr->client.sin_addr),
htons(argptr->client.sin_port),
ack.block_num,
bnum
);
if (ack.block_num == bnum) {
rxon = 0;
verif = 1;
break;
}
if (ack.block_num == (bnum - 1)) {
rxon = 0;
vcount++;
break;
}
}
if (++rxcount > 30) {
//TODO: error response function!
}
}
}
free(packet);
if (num_read < 512) {
lon = 0;
}
}
socket_clean:
close(s);
cleanup:
fclose(fp);
free(buf);
free(rxb);
free(fname);
free(wd);
free(args);
return (void *)NULL;
pre_socket:
if (fp != NULL) {
fclose(fp);
}
free(buf);
free(rxb);
free(fname);
free(wd);
return nbd_nbtpd_resp_error(args);
}
void *write_req_resp(void *args) {
free(args);
return (void *)NULL;
}
void *nbd_nbtpd_resp_error(void *args) {
//TODO: open socket and scream error, then cleanup.
//TODO: error response function!
free(args);
return (void *)NULL;
}
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