static int tftp_send_oack(struct tftp_session *spt,
const char *keys[], uint32_t values[], int nb,
struct tftp_t *recv_tp)
{
struct mbuf *m;
struct tftp_t *tp;
int i, n = 0;
m = m_get(spt->slirp);
if (!m)
return -1;
tp = tftp_prep_mbuf_data(spt, m);
tp->tp_op = htons(TFTP_OACK);
for (i = 0; i < nb; i++) {
n += snprintf(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%s",
keys[i]) + 1;
n += snprintf(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%u",
values[i]) + 1;
}
m->m_len = sizeof(struct tftp_t) - 514 + n - sizeof(struct udphdr);
tftp_udp_output(spt, m, recv_tp);
return 0;
}
static void tftp_send_error(struct tftp_session *spt,
uint16_t errorcode, const char *msg,
struct tftp_t *recv_tp)
{
struct mbuf *m;
struct tftp_t *tp;
m = m_get(spt->slirp);
if (!m) {
goto out;
}
tp = tftp_prep_mbuf_data(spt, m);
tp->tp_op = htons(TFTP_ERROR);
tp->x.tp_error.tp_error_code = htons(errorcode);
pstrcpy((char *)tp->x.tp_error.tp_msg, sizeof(tp->x.tp_error.tp_msg), msg);
m->m_len = sizeof(struct tftp_t) - 514 + 3 + strlen(msg)
- sizeof(struct udphdr);
tftp_udp_output(spt, m, recv_tp);
out:
tftp_session_terminate(spt);
}
static void tftp_send_next_block(struct tftp_session *spt,
struct tftp_t *recv_tp)
{
struct mbuf *m;
struct tftp_t *tp;
int nobytes;
m = m_get(spt->slirp);
if (!m) {
return;
}
tp = tftp_prep_mbuf_data(spt, m);
tp->tp_op = htons(TFTP_DATA);
tp->x.tp_data.tp_block_nr = htons((spt->block_nr + 1) & 0xffff);
nobytes = tftp_read_data(spt, spt->block_nr, tp->x.tp_data.tp_buf,
spt->block_size);
if (nobytes < 0) {
m_free(m);
/* send "file not found" error back */
tftp_send_error(spt, 1, "File not found", tp);
return;
}
m->m_len = sizeof(struct tftp_t) - (TFTP_BLOCKSIZE_MAX - nobytes)
- sizeof(struct udphdr);
tftp_udp_output(spt, m, recv_tp);
if (nobytes == spt->block_size) {
tftp_session_update(spt);
}
else {
tftp_session_terminate(spt);
}
spt->block_nr++;
}