void check_tftp_listeners(time_t now)
{
struct tftp_transfer *transfer, *tmp, **up;
ssize_t len;
struct ack {
unsigned short op, block;
} *mess = (struct ack *)daemon->packet;
/* Check for activity on any existing transfers */
for (transfer = daemon->tftp_trans, up = &daemon->tftp_trans; transfer; transfer = tmp)
{
tmp = transfer->next;
prettyprint_addr(&transfer->peer, daemon->addrbuff);
if (poll_check(transfer->sockfd, POLLIN))
{
/* we overwrote the buffer... */
daemon->srv_save = NULL;
if ((len = recv(transfer->sockfd, daemon->packet, daemon->packet_buff_sz, 0)) >= (ssize_t)sizeof(struct ack))
{
if (ntohs(mess->op) == OP_ACK && ntohs(mess->block) == (unsigned short)transfer->block)
{
/* Got ack, ensure we take the (re)transmit path */
transfer->timeout = now;
transfer->backoff = 0;
if (transfer->block++ != 0)
transfer->offset += transfer->blocksize - transfer->expansion;
}
else if (ntohs(mess->op) == OP_ERR)
{
char *p = daemon->packet + sizeof(struct ack);
char *end = daemon->packet + len;
char *err = next(&p, end);
/* Sanitise error message */
if (!err)
err = "";
else
sanitise(err);
my_syslog(MS_TFTP | LOG_ERR, _("error %d %s received from %s"),
(int)ntohs(mess->block), err,
daemon->addrbuff);
/* Got err, ensure we take abort */
transfer->timeout = now;
transfer->backoff = 100;
}
}
}
if (difftime(now, transfer->timeout) >= 0.0)
{
int endcon = 0;
/* timeout, retransmit */
transfer->timeout += 1 + (1<<transfer->backoff);
/* we overwrote the buffer... */
daemon->srv_save = NULL;
if ((len = get_block(daemon->packet, transfer)) == -1)
{
len = tftp_err_oops(daemon->packet, transfer->file->filename);
endcon = 1;
}
/* don't complain about timeout when we're awaiting the last
ACK, some clients never send it */
else if (++transfer->backoff > 7 && len != 0)
{
endcon = 1;
len = 0;
}
if (len != 0)
while(sendto(transfer->sockfd, daemon->packet, len, 0,
(struct sockaddr *)&transfer->peer, sa_len(&transfer->peer)) == -1 && errno == EINTR);
if (endcon || len == 0)
{
strcpy(daemon->namebuff, transfer->file->filename);
sanitise(daemon->namebuff);
my_syslog(MS_TFTP | LOG_INFO, endcon ? _("failed sending %s to %s") : _("sent %s to %s"), daemon->namebuff, daemon->addrbuff);
/* unlink */
*up = tmp;
if (endcon)
free_transfer(transfer);
else
{
/* put on queue to be sent to script and deleted */
transfer->next = daemon->tftp_done_trans;
daemon->tftp_done_trans = transfer;
}
continue;
}
}
up = &transfer->next;
}
}
void tftp_request(struct listener *listen, time_t now)
{
ssize_t len;
char *packet = daemon->packet;
char *filename, *mode, *p, *end, *opt;
union mysockaddr addr, peer;
struct msghdr msg;
struct iovec iov;
struct ifreq ifr;
int is_err = 1, if_index = 0, mtu = 0;
struct iname *tmp;
struct tftp_transfer *transfer;
int port = daemon->start_tftp_port; /* may be zero to use ephemeral port */
#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
int mtuflag = IP_PMTUDISC_DONT;
#endif
char namebuff[IF_NAMESIZE];
char *name = NULL;
char *prefix = daemon->tftp_prefix;
struct tftp_prefix *pref;
union all_addr addra;
/* Can always get recvd interface for IPv6 */
int check_dest = !option_bool(OPT_NOWILD) || listen->family == AF_INET6;
union {
struct cmsghdr align; /* this ensures alignment */
char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
#if defined(HAVE_LINUX_NETWORK)
char control[CMSG_SPACE(sizeof(struct in_pktinfo))];
#elif defined(HAVE_SOLARIS_NETWORK)
char control[CMSG_SPACE(sizeof(unsigned int))];
#elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF)
char control[CMSG_SPACE(sizeof(struct sockaddr_dl))];
#endif
} control_u;
msg.msg_controllen = sizeof(control_u);
msg.msg_control = control_u.control;
msg.msg_flags = 0;
msg.msg_name = &peer;
msg.msg_namelen = sizeof(peer);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
iov.iov_base = packet;
iov.iov_len = daemon->packet_buff_sz;
/* we overwrote the buffer... */
daemon->srv_save = NULL;
if ((len = recvmsg(listen->tftpfd, &msg, 0)) < 2)
return;
/* Can always get recvd interface for IPv6 */
if (!check_dest)
{
if (listen->iface)
{
addr = listen->iface->addr;
name = listen->iface->name;
mtu = listen->iface->mtu;
if (daemon->tftp_mtu != 0 && daemon->tftp_mtu < mtu)
mtu = daemon->tftp_mtu;
}
else
{
/* we're listening on an address that doesn't appear on an interface,
ask the kernel what the socket is bound to */
socklen_t tcp_len = sizeof(union mysockaddr);
if (getsockname(listen->tftpfd, (struct sockaddr *)&addr, &tcp_len) == -1)
return;
}
}
else
{
struct cmsghdr *cmptr;
if (msg.msg_controllen < sizeof(struct cmsghdr))
return;
addr.sa.sa_family = listen->family;
#if defined(HAVE_LINUX_NETWORK)
if (listen->family == AF_INET)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_PKTINFO)
{
union {
unsigned char *c;
struct in_pktinfo *p;
} p;
p.c = CMSG_DATA(cmptr);
addr.in.sin_addr = p.p->ipi_spec_dst;
if_index = p.p->ipi_ifindex;
}
#elif defined(HAVE_SOLARIS_NETWORK)
if (listen->family == AF_INET)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
{
union {
unsigned char *c;
struct in_addr *a;
unsigned int *i;
} p;
p.c = CMSG_DATA(cmptr);
if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR)
addr.in.sin_addr = *(p.a);
else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF)
if_index = *(p.i);
}
#elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF)
if (listen->family == AF_INET)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
{
union {
unsigned char *c;
struct in_addr *a;
struct sockaddr_dl *s;
} p;
p.c = CMSG_DATA(cmptr);
if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR)
addr.in.sin_addr = *(p.a);
else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF)
if_index = p.s->sdl_index;
}
#endif
if (listen->family == AF_INET6)
{
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == IPPROTO_IPV6 && cmptr->cmsg_type == daemon->v6pktinfo)
{
union {
unsigned char *c;
struct in6_pktinfo *p;
} p;
p.c = CMSG_DATA(cmptr);
addr.in6.sin6_addr = p.p->ipi6_addr;
if_index = p.p->ipi6_ifindex;
}
}
if (!indextoname(listen->tftpfd, if_index, namebuff))
return;
name = namebuff;
addra.addr4 = addr.in.sin_addr;
if (listen->family == AF_INET6)
addra.addr6 = addr.in6.sin6_addr;
if (daemon->tftp_interfaces)
{
/* dedicated tftp interface list */
for (tmp = daemon->tftp_interfaces; tmp; tmp = tmp->next)
if (tmp->name && wildcard_match(tmp->name, name))
break;
if (!tmp)
return;
}
else
{
/* Do the same as DHCP */
if (!iface_check(listen->family, &addra, name, NULL))
{
if (!option_bool(OPT_CLEVERBIND))
enumerate_interfaces(0);
if (!loopback_exception(listen->tftpfd, listen->family, &addra, name) &&
!label_exception(if_index, listen->family, &addra))
return;
}
#ifdef HAVE_DHCP
/* allowed interfaces are the same as for DHCP */
for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
if (tmp->name && wildcard_match(tmp->name, name))
return;
#endif
}
safe_strncpy(ifr.ifr_name, name, IF_NAMESIZE);
if (ioctl(listen->tftpfd, SIOCGIFMTU, &ifr) != -1)
{
mtu = ifr.ifr_mtu;
if (daemon->tftp_mtu != 0 && daemon->tftp_mtu < mtu)
mtu = daemon->tftp_mtu;
}
}
/* Failed to get interface mtu - can use configured value. */
if (mtu == 0)
mtu = daemon->tftp_mtu;
if (name)
{
/* check for per-interface prefix */
for (pref = daemon->if_prefix; pref; pref = pref->next)
if (strcmp(pref->interface, name) == 0)
prefix = pref->prefix;
}
if (listen->family == AF_INET)
{
addr.in.sin_port = htons(port);
#ifdef HAVE_SOCKADDR_SA_LEN
addr.in.sin_len = sizeof(addr.in);
#endif
}
else
{
addr.in6.sin6_port = htons(port);
addr.in6.sin6_flowinfo = 0;
addr.in6.sin6_scope_id = 0;
#ifdef HAVE_SOCKADDR_SA_LEN
addr.in6.sin6_len = sizeof(addr.in6);
#endif
}
if (!(transfer = whine_malloc(sizeof(struct tftp_transfer))))
return;
if ((transfer->sockfd = socket(listen->family, SOCK_DGRAM, 0)) == -1)
{
free(transfer);
return;
}
transfer->peer = peer;
transfer->timeout = now + 2;
transfer->backoff = 1;
transfer->block = 1;
transfer->blocksize = 512;
transfer->offset = 0;
transfer->file = NULL;
transfer->opt_blocksize = transfer->opt_transize = 0;
transfer->netascii = transfer->carrylf = 0;
prettyprint_addr(&peer, daemon->addrbuff);
/* if we have a nailed-down range, iterate until we find a free one. */
while (1)
{
if (bind(transfer->sockfd, &addr.sa, sa_len(&addr)) == -1 ||
#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
setsockopt(transfer->sockfd, IPPROTO_IP, IP_MTU_DISCOVER, &mtuflag, sizeof(mtuflag)) == -1 ||
#endif
!fix_fd(transfer->sockfd))
{
if (errno == EADDRINUSE && daemon->start_tftp_port != 0)
{
if (++port <= daemon->end_tftp_port)
{
if (listen->family == AF_INET)
addr.in.sin_port = htons(port);
else
addr.in6.sin6_port = htons(port);
continue;
}
my_syslog(MS_TFTP | LOG_ERR, _("unable to get free port for TFTP"));
}
free_transfer(transfer);
return;
}
break;
}
p = packet + 2;
end = packet + len;
if (ntohs(*((unsigned short *)packet)) != OP_RRQ ||
!(filename = next(&p, end)) ||
!(mode = next(&p, end)) ||
(strcasecmp(mode, "octet") != 0 && strcasecmp(mode, "netascii") != 0))
{
len = tftp_err(ERR_ILL, packet, _("unsupported request from %s"), daemon->addrbuff);
is_err = 1;
}
else
{
if (strcasecmp(mode, "netascii") == 0)
transfer->netascii = 1;
while ((opt = next(&p, end)))
{
if (strcasecmp(opt, "blksize") == 0)
{
if ((opt = next(&p, end)) && !option_bool(OPT_TFTP_NOBLOCK))
{
/* 32 bytes for IP, UDP and TFTP headers, 52 bytes for IPv6 */
int overhead = (listen->family == AF_INET) ? 32 : 52;
transfer->blocksize = atoi(opt);
if (transfer->blocksize < 1)
transfer->blocksize = 1;
if (transfer->blocksize > (unsigned)daemon->packet_buff_sz - 4)
transfer->blocksize = (unsigned)daemon->packet_buff_sz - 4;
if (mtu != 0 && transfer->blocksize > (unsigned)mtu - overhead)
transfer->blocksize = (unsigned)mtu - overhead;
transfer->opt_blocksize = 1;
transfer->block = 0;
}
}
else if (strcasecmp(opt, "tsize") == 0 && next(&p, end) && !transfer->netascii)
{
transfer->opt_transize = 1;
transfer->block = 0;
}
}
/* cope with backslashes from windows boxen. */
for (p = filename; *p; p++)
if (*p == '\\')
*p = '/';
else if (option_bool(OPT_TFTP_LC))
*p = tolower(*p);
strcpy(daemon->namebuff, "/");
if (prefix)
{
if (prefix[0] == '/')
daemon->namebuff[0] = 0;
strncat(daemon->namebuff, prefix, (MAXDNAME-1) - strlen(daemon->namebuff));
if (prefix[strlen(prefix)-1] != '/')
strncat(daemon->namebuff, "/", (MAXDNAME-1) - strlen(daemon->namebuff));
if (option_bool(OPT_TFTP_APREF_IP))
{
size_t oldlen = strlen(daemon->namebuff);
struct stat statbuf;
strncat(daemon->namebuff, daemon->addrbuff, (MAXDNAME-1) - strlen(daemon->namebuff));
strncat(daemon->namebuff, "/", (MAXDNAME-1) - strlen(daemon->namebuff));
/* remove unique-directory if it doesn't exist */
if (stat(daemon->namebuff, &statbuf) == -1 || !S_ISDIR(statbuf.st_mode))
daemon->namebuff[oldlen] = 0;
}
if (option_bool(OPT_TFTP_APREF_MAC))
{
unsigned char *macaddr = NULL;
unsigned char macbuf[DHCP_CHADDR_MAX];
#ifdef HAVE_DHCP
if (daemon->dhcp && peer.sa.sa_family == AF_INET)
{
/* Check if the client IP is in our lease database */
struct dhcp_lease *lease = lease_find_by_addr(peer.in.sin_addr);
if (lease && lease->hwaddr_type == ARPHRD_ETHER && lease->hwaddr_len == ETHER_ADDR_LEN)
macaddr = lease->hwaddr;
}
#endif
/* If no luck, try to find in ARP table. This only works if client is in same (V)LAN */
if (!macaddr && find_mac(&peer, macbuf, 1, now) > 0)
macaddr = macbuf;
if (macaddr)
{
size_t oldlen = strlen(daemon->namebuff);
struct stat statbuf;
snprintf(daemon->namebuff + oldlen, (MAXDNAME-1) - oldlen, "%.2x-%.2x-%.2x-%.2x-%.2x-%.2x/",
macaddr[0], macaddr[1], macaddr[2], macaddr[3], macaddr[4], macaddr[5]);
/* remove unique-directory if it doesn't exist */
if (stat(daemon->namebuff, &statbuf) == -1 || !S_ISDIR(statbuf.st_mode))
daemon->namebuff[oldlen] = 0;
}
}
/* Absolute pathnames OK if they match prefix */
if (filename[0] == '/')
{
if (strstr(filename, daemon->namebuff) == filename)
daemon->namebuff[0] = 0;
else
filename++;
}
}
else if (filename[0] == '/')
daemon->namebuff[0] = 0;
strncat(daemon->namebuff, filename, (MAXDNAME-1) - strlen(daemon->namebuff));
/* check permissions and open file */
if ((transfer->file = check_tftp_fileperm(&len, prefix)))
{
if ((len = get_block(packet, transfer)) == -1)
len = tftp_err_oops(packet, daemon->namebuff);
else
is_err = 0;
}
}
while (sendto(transfer->sockfd, packet, len, 0,
(struct sockaddr *)&peer, sa_len(&peer)) == -1 && errno == EINTR);
if (is_err)
free_transfer(transfer);
else
{
transfer->next = daemon->tftp_trans;
daemon->tftp_trans = transfer;
}
}
static struct tftp_file *check_tftp_fileperm(ssize_t *len, char *prefix)
{
char *packet = daemon->packet, *namebuff = daemon->namebuff;
struct tftp_file *file;
struct tftp_transfer *t;
uid_t uid = geteuid();
struct stat statbuf;
int fd = -1;
/* trick to ban moving out of the subtree */
if (prefix && strstr(namebuff, "/../"))
goto perm;
if ((fd = open(namebuff, O_RDONLY)) == -1)
{
if (errno == ENOENT)
{
*len = tftp_err(ERR_FNF, packet, _("file %s not found"), namebuff);
return NULL;
}
else if (errno == EACCES)
goto perm;
else
goto oops;
}
/* stat the file descriptor to avoid stat->open races */
if (fstat(fd, &statbuf) == -1)
goto oops;
/* running as root, must be world-readable */
if (uid == 0)
{
if (!(statbuf.st_mode & S_IROTH))
goto perm;
}
/* in secure mode, must be owned by user running dnsmasq */
else if (option_bool(OPT_TFTP_SECURE) && uid != statbuf.st_uid)
goto perm;
/* If we're doing many transfers from the same file, only
open it once this saves lots of file descriptors
when mass-booting a big cluster, for instance.
Be conservative and only share when inode and name match
this keeps error messages sane. */
for (t = daemon->tftp_trans; t; t = t->next)
if (t->file->dev == statbuf.st_dev &&
t->file->inode == statbuf.st_ino &&
strcmp(t->file->filename, namebuff) == 0)
{
close(fd);
t->file->refcount++;
return t->file;
}
if (!(file = whine_malloc(sizeof(struct tftp_file) + strlen(namebuff) + 1)))
{
errno = ENOMEM;
goto oops;
}
file->fd = fd;
file->size = statbuf.st_size;
file->dev = statbuf.st_dev;
file->inode = statbuf.st_ino;
file->refcount = 1;
strcpy(file->filename, namebuff);
return file;
perm:
errno = EACCES;
*len = tftp_err(ERR_PERM, packet, _("cannot access %s: %s"), namebuff);
if (fd != -1)
close(fd);
return NULL;
oops:
*len = tftp_err_oops(packet, namebuff);
if (fd != -1)
close(fd);
return NULL;
}
void tftp_request(struct listener *listen, struct daemon *daemon, time_t now)
{
ssize_t len;
char *packet = daemon->packet;
char *filename, *mode, *p, *end, *opt;
struct sockaddr_in addr, peer;
struct msghdr msg;
struct cmsghdr *cmptr;
struct iovec iov;
struct ifreq ifr;
int is_err = 1, if_index = 0;
struct iname *tmp;
struct tftp_transfer *transfer, *t;
union {
struct cmsghdr align; /* this ensures alignment */
#ifdef HAVE_LINUX_NETWORK
char control[CMSG_SPACE(sizeof(struct in_pktinfo))];
#else
char control[CMSG_SPACE(sizeof(struct sockaddr_dl))];
#endif
} control_u;
msg.msg_controllen = sizeof(control_u);
msg.msg_control = control_u.control;
msg.msg_flags = 0;
msg.msg_name = &peer;
msg.msg_namelen = sizeof(peer);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
iov.iov_base = packet;
iov.iov_len = daemon->packet_buff_sz;
/* we overwrote the buffer... */
daemon->srv_save = NULL;
if ((len = recvmsg(listen->tftpfd, &msg, 0)) < 2)
return;
if (daemon->options & OPT_NOWILD)
addr = listen->iface->addr.in;
else
{
addr.sin_addr.s_addr = 0;
#if defined(HAVE_LINUX_NETWORK)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == SOL_IP && cmptr->cmsg_type == IP_PKTINFO)
{
addr.sin_addr = ((struct in_pktinfo *)CMSG_DATA(cmptr))->ipi_spec_dst;
if_index = ((struct in_pktinfo *)CMSG_DATA(cmptr))->ipi_ifindex;
}
if (!(ifr.ifr_ifindex = if_index) ||
ioctl(listen->tftpfd, SIOCGIFNAME, &ifr) == -1)
return;
#elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR)
addr.sin_addr = *((struct in_addr *)CMSG_DATA(cmptr));
else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF)
if_index = ((struct sockaddr_dl *)CMSG_DATA(cmptr))->sdl_index;
if (if_index == 0 || !if_indextoname(if_index, ifr.ifr_name))
return;
#endif
if (addr.sin_addr.s_addr == 0)
return;
if (!iface_check(daemon, AF_INET, (struct all_addr *)&addr, &ifr, &if_index))
return;
/* allowed interfaces are the same as for DHCP */
for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
if (tmp->name && (strcmp(tmp->name, ifr.ifr_name) == 0))
return;
}
/* tell kernel to use ephemeral port */
addr.sin_port = 0;
addr.sin_family = AF_INET;
#ifdef HAVE_SOCKADDR_SA_LEN
addr.sin_len = sizeof(addr);
#endif
if (!(transfer = malloc(sizeof(struct tftp_transfer))))
return;
if ((transfer->sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
{
free(transfer);
return;
}
transfer->peer = peer;
transfer->timeout = now + 1;
transfer->backoff = 1;
transfer->block = 1;
transfer->blocksize = 512;
transfer->file = NULL;
transfer->opt_blocksize = transfer->opt_transize = 0;
if (bind(transfer->sockfd, (struct sockaddr *)&addr, sizeof(addr)) == -1 ||
!fix_fd(transfer->sockfd))
{
free_transfer(transfer);
return;
}
p = packet + 2;
end = packet + len;
if (ntohs(*((unsigned short *)packet)) != OP_RRQ ||
!(filename = next(&p, end)) ||
!(mode = next(&p, end)) ||
strcasecmp(mode, "octet") != 0)
len = tftp_err(ERR_ILL, packet, _("unsupported request from %s"), inet_ntoa(peer.sin_addr));
else
{
while ((opt = next(&p, end)))
{
if (strcasecmp(opt, "blksize") == 0 &&
(opt = next(&p, end)) &&
!(daemon->options & OPT_TFTP_NOBLOCK))
{
transfer->blocksize = atoi(opt);
if (transfer->blocksize < 1)
transfer->blocksize = 1;
if (transfer->blocksize > (unsigned)daemon->packet_buff_sz - 4)
transfer->blocksize = (unsigned)daemon->packet_buff_sz - 4;
transfer->opt_blocksize = 1;
transfer->block = 0;
}
if (strcasecmp(opt, "tsize") == 0 && next(&p, end))
{
transfer->opt_transize = 1;
transfer->block = 0;
}
}
if (daemon->tftp_prefix)
{
strncpy(daemon->namebuff, daemon->tftp_prefix, MAXDNAME);
if (daemon->tftp_prefix[strlen(daemon->tftp_prefix)-1] != '/' &&
filename[0] != '/')
strncat(daemon->namebuff, "/", MAXDNAME);
}
else if (filename[0] != '/')
strncpy(daemon->namebuff, "/", MAXDNAME);
else
daemon->namebuff[0] = 0;
strncat(daemon->namebuff, filename, MAXDNAME);
daemon->namebuff[MAXDNAME-1] = 0;
/* If we're doing many tranfers from the same file, only
open it once this saves lots of file descriptors
when mass-booting a big cluster, for instance. */
for (t = daemon->tftp_trans; t; t = t->next)
if (strcmp(t->file->filename, daemon->namebuff) == 0)
break;
if (t)
{
/* file already open */
transfer->file = t->file;
transfer->file->refcount++;
}
else
/* check permissions and open file */
transfer->file = check_tftp_fileperm(daemon, &len);
if (transfer->file)
{
if ((len = get_block(packet, transfer)) == -1)
len = tftp_err_oops(packet, daemon->namebuff);
else
is_err = 0;
}
}
while (sendto(transfer->sockfd, packet, len, 0,
(struct sockaddr *)&peer, sizeof(peer)) == -1 && errno == EINTR);
if (is_err)
free_transfer(transfer);
else
{
syslog(LOG_INFO, _("TFTP sent %s to %s"), daemon->namebuff, inet_ntoa(peer.sin_addr));
transfer->next = daemon->tftp_trans;
daemon->tftp_trans = transfer;
}
}
void check_tftp_listeners(struct daemon *daemon, fd_set *rset, time_t now)
{
struct tftp_transfer *transfer, *tmp, **up;
ssize_t len;
struct ack {
unsigned short op, block;
} *mess = (struct ack *)daemon->packet;
/* Check for activity on any existing transfers */
for (transfer = daemon->tftp_trans, up = &daemon->tftp_trans; transfer; transfer = tmp)
{
tmp = transfer->next;
if (FD_ISSET(transfer->sockfd, rset))
{
/* we overwrote the buffer... */
daemon->srv_save = NULL;
if ((len = recv(transfer->sockfd, daemon->packet, daemon->packet_buff_sz, 0)) >= (ssize_t)sizeof(struct ack))
{
if (ntohs(mess->op) == OP_ACK && ntohs(mess->block) == (unsigned short)transfer->block)
{
/* Got ack, ensure we take the (re)transmit path */
transfer->timeout = now;
transfer->backoff = 0;
transfer->block++;
}
else if (ntohs(mess->op) == OP_ERR)
{
char *p = daemon->packet + sizeof(struct ack);
char *end = daemon->packet + len;
char *err = next(&p, end);
/* Sanitise error message */
if (!err)
err = "";
else
{
char *q, *r;
for (q = r = err; *r; r++)
if (isprint(*r))
*(q++) = *r;
*q = 0;
}
syslog(LOG_ERR, _("TFTP error %d %s received from %s"),
(int)ntohs(mess->block), err,
inet_ntoa(transfer->peer.sin_addr));
/* Got err, ensure we take abort */
transfer->timeout = now;
transfer->backoff = 100;
}
}
}
if (difftime(now, transfer->timeout) >= 0.0)
{
int endcon = 0;
/* timeout, retransmit */
transfer->timeout += 1<<(transfer->backoff);
/* we overwrote the buffer... */
daemon->srv_save = NULL;
if ((len = get_block(daemon->packet, transfer)) == -1)
{
len = tftp_err_oops(daemon->packet, transfer->file->filename);
endcon = 1;
}
else if (++transfer->backoff > 5)
{
/* don't complain about timeout when we're awaiting the last
ACK, some clients never send it */
if (len != 0)
syslog(LOG_ERR, _("TFTP failed sending %s to %s"),
transfer->file->filename, inet_ntoa(transfer->peer.sin_addr));
len = 0;
}
if (len != 0)
while(sendto(transfer->sockfd, daemon->packet, len, 0,
(struct sockaddr *)&transfer->peer, sizeof(transfer->peer)) == -1 && errno == EINTR);
if (endcon || len == 0)
{
/* unlink */
*up = tmp;
free_transfer(transfer);
continue;
}
}
up = &transfer->next;
}
}
static struct tftp_file *check_tftp_fileperm(struct daemon *daemon, ssize_t *len)
{
char *packet = daemon->packet, *namebuff = daemon->namebuff;
struct tftp_file *file;
uid_t uid = geteuid();
struct stat statbuf;
/* trick to ban moving out of the subtree */
if (daemon->tftp_prefix && strstr(namebuff, "/../"))
{
errno = EACCES;
goto perm;
}
if (stat(namebuff, &statbuf) == -1)
{
if (errno == ENOENT || errno == ENOTDIR)
goto nofile;
else if (errno == EACCES)
goto perm;
else
goto oops;
}
/* running as root, must be world-readable */
if (uid == 0)
{
if (!(statbuf.st_mode & S_IROTH))
{
errno = EACCES;
goto perm;
}
}
/* in secure mode, must be owned by user running dnsmasq */
else if ((daemon->options & OPT_TFTP_SECURE) && uid != statbuf.st_uid)
{
errno = EACCES;
goto perm;
}
if (!(file = malloc(sizeof(struct tftp_file) + strlen(namebuff) + 1)))
{
errno = ENOMEM;
goto oops;
}
if ((file->fd = open(namebuff, O_RDONLY)) == -1)
{
free(file);
if (errno == EACCES || errno == EISDIR)
goto perm;
else
goto oops;
}
file->size = statbuf.st_size;
file->refcount = 1;
strcpy(file->filename, namebuff);
return file;
nofile:
*len = tftp_err(ERR_FNF, packet, _("file %s not found"), namebuff);
return NULL;
perm:
*len = tftp_err(ERR_PERM, packet, _("cannot access %s: %s"), namebuff);
return NULL;
oops:
*len = tftp_err_oops(packet, namebuff);
return NULL;
}
void tftp_request(struct listener *listen, time_t now)
{
ssize_t len;
char *packet = daemon->packet;
char *filename, *mode, *p, *end, *opt;
struct sockaddr_in addr, peer;
struct msghdr msg;
struct cmsghdr *cmptr;
struct iovec iov;
struct ifreq ifr;
int is_err = 1, if_index = 0;
struct iname *tmp;
struct tftp_transfer *transfer;
int port = daemon->start_tftp_port; /* may be zero to use ephemeral port */
#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
int mtu = IP_PMTUDISC_DONT;
#endif
union {
struct cmsghdr align; /* this ensures alignment */
#if defined(HAVE_LINUX_NETWORK)
char control[CMSG_SPACE(sizeof(struct in_pktinfo))];
#elif defined(HAVE_SOLARIS_NETWORK)
char control[CMSG_SPACE(sizeof(unsigned int))];
#else
char control[CMSG_SPACE(sizeof(struct sockaddr_dl))];
#endif
} control_u;
msg.msg_controllen = sizeof(control_u);
msg.msg_control = control_u.control;
msg.msg_flags = 0;
msg.msg_name = &peer;
msg.msg_namelen = sizeof(peer);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
iov.iov_base = packet;
iov.iov_len = daemon->packet_buff_sz;
/* we overwrote the buffer... */
daemon->srv_save = NULL;
if ((len = recvmsg(listen->tftpfd, &msg, 0)) < 2)
return;
if (daemon->options & OPT_NOWILD)
addr = listen->iface->addr.in;
else
{
addr.sin_addr.s_addr = 0;
#if defined(HAVE_LINUX_NETWORK)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == SOL_IP && cmptr->cmsg_type == IP_PKTINFO)
{
addr.sin_addr = ((struct in_pktinfo *)CMSG_DATA(cmptr))->ipi_spec_dst;
if_index = ((struct in_pktinfo *)CMSG_DATA(cmptr))->ipi_ifindex;
}
if (!(ifr.ifr_ifindex = if_index) ||
ioctl(listen->tftpfd, SIOCGIFNAME, &ifr) == -1)
return;
#elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR)
addr.sin_addr = *((struct in_addr *)CMSG_DATA(cmptr));
else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF)
#ifdef HAVE_SOLARIS_NETWORK
if_index = *((unsigned int *)CMSG_DATA(cmptr));
#else
if_index = ((struct sockaddr_dl *)CMSG_DATA(cmptr))->sdl_index;
#endif
if (if_index == 0 || !if_indextoname(if_index, ifr.ifr_name))
return;
#endif
if (addr.sin_addr.s_addr == 0)
return;
if (!iface_check(AF_INET, (struct all_addr *)&addr.sin_addr,
&ifr, &if_index))
return;
/* allowed interfaces are the same as for DHCP */
for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
if (tmp->name && (strcmp(tmp->name, ifr.ifr_name) == 0))
return;
}
addr.sin_port = htons(port);
addr.sin_family = AF_INET;
#ifdef HAVE_SOCKADDR_SA_LEN
addr.sin_len = sizeof(addr);
#endif
if (!(transfer = whine_malloc(sizeof(struct tftp_transfer))))
return;
if ((transfer->sockfd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
{
free(transfer);
return;
}
transfer->peer = peer;
transfer->timeout = now + 2;
transfer->backoff = 1;
transfer->block = 1;
transfer->blocksize = 512;
transfer->offset = 0;
transfer->file = NULL;
transfer->opt_blocksize = transfer->opt_transize = 0;
transfer->netascii = transfer->carrylf = 0;
/* if we have a nailed-down range, iterate until we find a free one. */
while (1)
{
if (bind(transfer->sockfd, (struct sockaddr *)&addr, sizeof(addr)) == -1 ||
#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
setsockopt(transfer->sockfd, SOL_IP, IP_MTU_DISCOVER, &mtu, sizeof(mtu)) == -1 ||
#endif
!fix_fd(transfer->sockfd))
{
if (errno == EADDRINUSE && daemon->start_tftp_port != 0)
{
if (++port <= daemon->end_tftp_port)
{
addr.sin_port = htons(port);
continue;
}
my_syslog(LOG_ERR, _("unable to get free port for TFTP"));
}
free_transfer(transfer);
return;
}
break;
}
p = packet + 2;
end = packet + len;
if (ntohs(*((unsigned short *)packet)) != OP_RRQ ||
!(filename = next(&p, end)) ||
!(mode = next(&p, end)) ||
(strcasecmp(mode, "octet") != 0 && strcasecmp(mode, "netascii") != 0))
len = tftp_err(ERR_ILL, packet, _("unsupported request from %s"), inet_ntoa(peer.sin_addr));
else
{
if (strcasecmp(mode, "netascii") == 0)
transfer->netascii = 1;
while ((opt = next(&p, end)))
{
if (strcasecmp(opt, "blksize") == 0)
{
if ((opt = next(&p, end)) &&
!(daemon->options & OPT_TFTP_NOBLOCK))
{
transfer->blocksize = atoi(opt);
if (transfer->blocksize < 1)
transfer->blocksize = 1;
if (transfer->blocksize > (unsigned)daemon->packet_buff_sz - 4)
transfer->blocksize = (unsigned)daemon->packet_buff_sz - 4;
transfer->opt_blocksize = 1;
transfer->block = 0;
}
}
else if (strcasecmp(opt, "tsize") == 0 && next(&p, end) && !transfer->netascii)
{
transfer->opt_transize = 1;
transfer->block = 0;
}
}
strcpy(daemon->namebuff, "/");
if (daemon->tftp_prefix)
{
if (daemon->tftp_prefix[0] == '/')
daemon->namebuff[0] = 0;
strncat(daemon->namebuff, daemon->tftp_prefix, (MAXDNAME-1) - strlen(daemon->namebuff));
if (daemon->tftp_prefix[strlen(daemon->tftp_prefix)-1] != '/')
strncat(daemon->namebuff, "/", (MAXDNAME-1) - strlen(daemon->namebuff));
if (daemon->options & OPT_TFTP_APREF)
{
size_t oldlen = strlen(daemon->namebuff);
struct stat statbuf;
strncat(daemon->namebuff, inet_ntoa(peer.sin_addr), (MAXDNAME-1) - strlen(daemon->namebuff));
strncat(daemon->namebuff, "/", (MAXDNAME-1) - strlen(daemon->namebuff));
/* remove unique-directory if it doesn't exist */
if (stat(daemon->namebuff, &statbuf) == -1 || !S_ISDIR(statbuf.st_mode))
daemon->namebuff[oldlen] = 0;
}
/* Absolute pathnames OK if they match prefix */
if (filename[0] == '/')
{
if (strstr(filename, daemon->namebuff) == filename)
daemon->namebuff[0] = 0;
else
filename++;
}
}
else if (filename[0] == '/')
daemon->namebuff[0] = 0;
strncat(daemon->namebuff, filename, (MAXDNAME-1) - strlen(daemon->namebuff));
/* check permissions and open file */
if ((transfer->file = check_tftp_fileperm(&len)))
{
if ((len = get_block(packet, transfer)) == -1)
len = tftp_err_oops(packet, daemon->namebuff);
else
is_err = 0;
}
}
while (sendto(transfer->sockfd, packet, len, 0,
(struct sockaddr *)&peer, sizeof(peer)) == -1 && errno == EINTR);
if (is_err)
free_transfer(transfer);
else
{
my_syslog(LOG_INFO, _("TFTP sent %s to %s"), daemon->namebuff, inet_ntoa(peer.sin_addr));
transfer->next = daemon->tftp_trans;
daemon->tftp_trans = transfer;
}
}
void tftp_request(struct listener *listen, time_t now)
{
ssize_t len;
char *packet = daemon->packet;
char *filename, *mode, *p, *end, *opt;
union mysockaddr addr, peer;
struct msghdr msg;
struct iovec iov;
struct ifreq ifr;
int is_err = 1, if_index = 0, mtu = 0, special = 0;
#ifdef HAVE_DHCP
struct iname *tmp;
#endif
struct tftp_transfer *transfer;
int port = daemon->start_tftp_port; /* may be zero to use ephemeral port */
#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
int mtuflag = IP_PMTUDISC_DONT;
#endif
char namebuff[IF_NAMESIZE];
char pretty_addr[ADDRSTRLEN];
char *name;
char *prefix = daemon->tftp_prefix;
struct tftp_prefix *pref;
struct interface_list *ir;
union {
struct cmsghdr align; /* this ensures alignment */
#ifdef HAVE_IPV6
char control6[CMSG_SPACE(sizeof(struct in6_pktinfo))];
#endif
#if defined(HAVE_LINUX_NETWORK)
char control[CMSG_SPACE(sizeof(struct in_pktinfo))];
#elif defined(HAVE_SOLARIS_NETWORK)
char control[CMSG_SPACE(sizeof(unsigned int))];
#elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF)
char control[CMSG_SPACE(sizeof(struct sockaddr_dl))];
#endif
} control_u;
msg.msg_controllen = sizeof(control_u);
msg.msg_control = control_u.control;
msg.msg_flags = 0;
msg.msg_name = &peer;
msg.msg_namelen = sizeof(peer);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
iov.iov_base = packet;
iov.iov_len = daemon->packet_buff_sz;
/* we overwrote the buffer... */
daemon->srv_save = NULL;
if ((len = recvmsg(listen->tftpfd, &msg, 0)) < 2)
return;
if (option_bool(OPT_NOWILD))
{
addr = listen->iface->addr;
mtu = listen->iface->mtu;
name = listen->iface->name;
}
else
{
struct cmsghdr *cmptr;
int check;
struct interface_list *ir;
if (msg.msg_controllen < sizeof(struct cmsghdr))
return;
addr.sa.sa_family = listen->family;
#if defined(HAVE_LINUX_NETWORK)
if (listen->family == AF_INET)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == SOL_IP && cmptr->cmsg_type == IP_PKTINFO)
{
union {
unsigned char *c;
struct in_pktinfo *p;
} p;
p.c = CMSG_DATA(cmptr);
addr.in.sin_addr = p.p->ipi_spec_dst;
if_index = p.p->ipi_ifindex;
}
#elif defined(HAVE_SOLARIS_NETWORK)
if (listen->family == AF_INET)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
{
union {
unsigned char *c;
struct in_addr *a;
unsigned int *i;
} p;
p.c = CMSG_DATA(cmptr);
if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR)
addr.in.sin_addr = *(p.a);
else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF)
if_index = *(p.i);
}
#elif defined(IP_RECVDSTADDR) && defined(IP_RECVIF)
if (listen->family == AF_INET)
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
{
union {
unsigned char *c;
struct in_addr *a;
struct sockaddr_dl *s;
} p;
p.c = CMSG_DATA(cmptr);
if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVDSTADDR)
addr.in.sin_addr = *(p.a);
else if (cmptr->cmsg_level == IPPROTO_IP && cmptr->cmsg_type == IP_RECVIF)
if_index = p.s->sdl_index;
}
#endif
#ifdef HAVE_IPV6
if (listen->family == AF_INET6)
{
for (cmptr = CMSG_FIRSTHDR(&msg); cmptr; cmptr = CMSG_NXTHDR(&msg, cmptr))
if (cmptr->cmsg_level == IPV6_LEVEL && cmptr->cmsg_type == daemon->v6pktinfo)
{
union {
unsigned char *c;
struct in6_pktinfo *p;
} p;
p.c = CMSG_DATA(cmptr);
addr.in6.sin6_addr = p.p->ipi6_addr;
if_index = p.p->ipi6_ifindex;
}
}
#endif
if (!indextoname(listen->tftpfd, if_index, namebuff))
return;
name = namebuff;
#ifdef HAVE_IPV6
if (listen->family == AF_INET6)
check = iface_check(AF_INET6, (struct all_addr *)&addr.in6.sin6_addr, name, &if_index);
else
#endif
check = iface_check(AF_INET, (struct all_addr *)&addr.in.sin_addr, name, &if_index);
/* wierd TFTP service override */
for (ir = daemon->tftp_interfaces; ir; ir = ir->next)
if (strcmp(ir->interface, name) == 0)
break;
if (!ir)
{
if (!daemon->tftp_unlimited || !check)
return;
#ifdef HAVE_DHCP
/* allowed interfaces are the same as for DHCP */
for (tmp = daemon->dhcp_except; tmp; tmp = tmp->next)
if (tmp->name && (strcmp(tmp->name, name) == 0))
return;
#endif
}
strncpy(ifr.ifr_name, name, IF_NAMESIZE);
if (ioctl(listen->tftpfd, SIOCGIFMTU, &ifr) != -1)
mtu = ifr.ifr_mtu;
}
/* check for per-interface prefix */
for (pref = daemon->if_prefix; pref; pref = pref->next)
if (strcmp(pref->interface, name) == 0)
prefix = pref->prefix;
/* wierd TFTP interfaces disable special options. */
for (ir = daemon->tftp_interfaces; ir; ir = ir->next)
if (strcmp(ir->interface, name) == 0)
special = 1;
#ifdef HAVE_SOCKADDR_SA_LEN
addr.sa.sa_len = sa_len(&addr);
#endif
if (listen->family == AF_INET)
addr.in.sin_port = htons(port);
#ifdef HAVE_IPV6
else
{
addr.in6.sin6_port = htons(port);
addr.in6.sin6_flowinfo = 0;
}
#endif
if (!(transfer = whine_malloc(sizeof(struct tftp_transfer))))
return;
if ((transfer->sockfd = socket(listen->family, SOCK_DGRAM, 0)) == -1)
{
free(transfer);
return;
}
transfer->peer = peer;
transfer->timeout = now + 2;
transfer->backoff = 1;
transfer->block = 1;
transfer->blocksize = 512;
transfer->offset = 0;
transfer->file = NULL;
transfer->opt_blocksize = transfer->opt_transize = 0;
transfer->netascii = transfer->carrylf = 0;
prettyprint_addr(&peer, pretty_addr);
/* if we have a nailed-down range, iterate until we find a free one. */
while (1)
{
if (bind(transfer->sockfd, &addr.sa, sizeof(addr)) == -1 ||
#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
setsockopt(transfer->sockfd, SOL_IP, IP_MTU_DISCOVER, &mtuflag, sizeof(mtuflag)) == -1 ||
#endif
!fix_fd(transfer->sockfd))
{
if (errno == EADDRINUSE && daemon->start_tftp_port != 0)
{
if (++port <= daemon->end_tftp_port)
{
if (listen->family == AF_INET)
addr.in.sin_port = htons(port);
#ifdef HAVE_IPV6
else
addr.in6.sin6_port = htons(port);
#endif
continue;
}
my_syslog(MS_TFTP | LOG_ERR, _("unable to get free port for TFTP"));
}
free_transfer(transfer);
return;
}
break;
}
p = packet + 2;
end = packet + len;
if (ntohs(*((unsigned short *)packet)) != OP_RRQ ||
!(filename = next(&p, end)) ||
!(mode = next(&p, end)) ||
(strcasecmp(mode, "octet") != 0 && strcasecmp(mode, "netascii") != 0))
len = tftp_err(ERR_ILL, packet, _("unsupported request from %s"), pretty_addr);
else
{
if (strcasecmp(mode, "netascii") == 0)
transfer->netascii = 1;
while ((opt = next(&p, end)))
{
if (strcasecmp(opt, "blksize") == 0)
{
if ((opt = next(&p, end)) &&
(special || !option_bool(OPT_TFTP_NOBLOCK)))
{
transfer->blocksize = atoi(opt);
if (transfer->blocksize < 1)
transfer->blocksize = 1;
if (transfer->blocksize > (unsigned)daemon->packet_buff_sz - 4)
transfer->blocksize = (unsigned)daemon->packet_buff_sz - 4;
/* 32 bytes for IP, UDP and TFTP headers */
if (mtu != 0 && transfer->blocksize > (unsigned)mtu - 32)
transfer->blocksize = (unsigned)mtu - 32;
transfer->opt_blocksize = 1;
transfer->block = 0;
}
}
else if (strcasecmp(opt, "tsize") == 0 && next(&p, end) && !transfer->netascii)
{
transfer->opt_transize = 1;
transfer->block = 0;
}
}
/* cope with backslashes from windows boxen. */
while ((p = strchr(filename, '\\')))
*p = '/';
strcpy(daemon->namebuff, "/");
if (prefix)
{
if (prefix[0] == '/')
daemon->namebuff[0] = 0;
strncat(daemon->namebuff, prefix, (MAXDNAME-1) - strlen(daemon->namebuff));
if (prefix[strlen(prefix)-1] != '/')
strncat(daemon->namebuff, "/", (MAXDNAME-1) - strlen(daemon->namebuff));
if (!special && option_bool(OPT_TFTP_APREF))
{
size_t oldlen = strlen(daemon->namebuff);
struct stat statbuf;
strncat(daemon->namebuff, pretty_addr, (MAXDNAME-1) - strlen(daemon->namebuff));
strncat(daemon->namebuff, "/", (MAXDNAME-1) - strlen(daemon->namebuff));
/* remove unique-directory if it doesn't exist */
if (stat(daemon->namebuff, &statbuf) == -1 || !S_ISDIR(statbuf.st_mode))
daemon->namebuff[oldlen] = 0;
}
/* Absolute pathnames OK if they match prefix */
if (filename[0] == '/')
{
if (strstr(filename, daemon->namebuff) == filename)
daemon->namebuff[0] = 0;
else
filename++;
}
}
else if (filename[0] == '/')
daemon->namebuff[0] = 0;
strncat(daemon->namebuff, filename, (MAXDNAME-1) - strlen(daemon->namebuff));
/* check permissions and open file */
if ((transfer->file = check_tftp_fileperm(&len, prefix, special)))
{
if ((len = get_block(packet, transfer)) == -1)
len = tftp_err_oops(packet, daemon->namebuff);
else
is_err = 0;
}
}
while (sendto(transfer->sockfd, packet, len, 0,
(struct sockaddr *)&peer, sizeof(peer)) == -1 && errno == EINTR);
if (is_err)
free_transfer(transfer);
else
{
transfer->next = daemon->tftp_trans;
daemon->tftp_trans = transfer;
}
}
