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Commit 990163cf authored by Marc-André Lureau's avatar Marc-André Lureau
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tftp: introduce a header structure 



Instead of using a composed structure and potentially reading past the
incoming buffer, use a different structure for the header.

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
parent 3f179481
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src/tftp.c
View file @ 990163cf
......@@ -50,7 +50,7 @@ static void tftp_session_terminate(struct tftp_session *spt)
}
static int tftp_session_allocate(Slirp *slirp, struct sockaddr_storage *srcsas,
struct tftp_t *tp)
struct tftphdr *hdr)
{
struct tftp_session *spt;
int k;
......@@ -75,7 +75,7 @@ found:
memcpy(&spt->client_addr, srcsas, sockaddr_size(srcsas));
spt->fd = -1;
spt->block_size = 512;
spt->client_port = tp->udp.uh_sport;
spt->client_port = hdr->udp.uh_sport;
spt->slirp = slirp;
tftp_session_update(spt);
......@@ -84,7 +84,7 @@ found:
}
static int tftp_session_find(Slirp *slirp, struct sockaddr_storage *srcsas,
struct tftp_t *tp)
struct tftphdr *hdr)
{
struct tftp_session *spt;
int k;
......@@ -94,7 +94,7 @@ static int tftp_session_find(Slirp *slirp, struct sockaddr_storage *srcsas,
if (tftp_session_in_use(spt)) {
if (sockaddr_equal(&spt->client_addr, srcsas)) {
if (spt->client_port == tp->udp.uh_sport) {
if (spt->client_port == hdr->udp.uh_sport) {
return k;
}
}
......@@ -148,13 +148,13 @@ static struct tftp_t *tftp_prep_mbuf_data(struct tftp_session *spt,
}
static void tftp_udp_output(struct tftp_session *spt, struct mbuf *m,
struct tftp_t *recv_tp)
struct tftphdr *hdr)
{
if (spt->client_addr.ss_family == AF_INET6) {
struct sockaddr_in6 sa6, da6;
sa6.sin6_addr = spt->slirp->vhost_addr6;
sa6.sin6_port = recv_tp->udp.uh_dport;
sa6.sin6_port = hdr->udp.uh_dport;
da6.sin6_addr = ((struct sockaddr_in6 *)&spt->client_addr)->sin6_addr;
da6.sin6_port = spt->client_port;
......@@ -163,7 +163,7 @@ static void tftp_udp_output(struct tftp_session *spt, struct mbuf *m,
struct sockaddr_in sa4, da4;
sa4.sin_addr = spt->slirp->vhost_addr;
sa4.sin_port = recv_tp->udp.uh_dport;
sa4.sin_port = hdr->udp.uh_dport;
da4.sin_addr = ((struct sockaddr_in *)&spt->client_addr)->sin_addr;
da4.sin_port = spt->client_port;
......@@ -185,14 +185,14 @@ static int tftp_send_oack(struct tftp_session *spt, const char *keys[],
tp = tftp_prep_mbuf_data(spt, m);
tp->tp_op = htons(TFTP_OACK);
tp->hdr.tp_op = htons(TFTP_OACK);
for (i = 0; i < nb; i++) {
n += slirp_fmt0(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%s", keys[i]);
n += slirp_fmt0(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%u", values[i]);
}
m->m_len = G_SIZEOF_MEMBER(struct tftp_t, tp_op) + n;
tftp_udp_output(spt, m, recv_tp);
m->m_len = G_SIZEOF_MEMBER(struct tftp_t, hdr.tp_op) + n;
tftp_udp_output(spt, m, &recv_tp->hdr);
return 0;
}
......@@ -213,21 +213,21 @@ static void tftp_send_error(struct tftp_session *spt, uint16_t errorcode,
tp = tftp_prep_mbuf_data(spt, m);
tp->tp_op = htons(TFTP_ERROR);
tp->hdr.tp_op = htons(TFTP_ERROR);
tp->x.tp_error.tp_error_code = htons(errorcode);
slirp_pstrcpy((char *)tp->x.tp_error.tp_msg, sizeof(tp->x.tp_error.tp_msg),
msg);
m->m_len = sizeof(struct tftp_t) - (TFTP_BLOCKSIZE_MAX + 2) + 3 +
strlen(msg) - sizeof(struct udphdr);
tftp_udp_output(spt, m, recv_tp);
tftp_udp_output(spt, m, &recv_tp->hdr);
out:
tftp_session_terminate(spt);
}
static void tftp_send_next_block(struct tftp_session *spt,
struct tftp_t *recv_tp)
struct tftphdr *hdr)
{
struct mbuf *m;
struct tftp_t *tp;
......@@ -241,7 +241,7 @@ static void tftp_send_next_block(struct tftp_session *spt,
tp = tftp_prep_mbuf_data(spt, m);
tp->tp_op = htons(TFTP_DATA);
tp->hdr.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,
......@@ -259,7 +259,7 @@ static void tftp_send_next_block(struct tftp_session *spt,
m->m_len = sizeof(struct tftp_t) - (TFTP_BLOCKSIZE_MAX - nobytes) -
sizeof(struct udphdr);
tftp_udp_output(spt, m, recv_tp);
tftp_udp_output(spt, m, hdr);
if (nobytes == spt->block_size) {
tftp_session_update(spt);
......@@ -282,12 +282,12 @@ static void tftp_handle_rrq(Slirp *slirp, struct sockaddr_storage *srcsas,
int nb_options = 0;
/* check if a session already exists and if so terminate it */
s = tftp_session_find(slirp, srcsas, tp);
s = tftp_session_find(slirp, srcsas, &tp->hdr);
if (s >= 0) {
tftp_session_terminate(&slirp->tftp_sessions[s]);
}
s = tftp_session_allocate(slirp, srcsas, tp);
s = tftp_session_allocate(slirp, srcsas, &tp->hdr);
if (s < 0) {
return;
......@@ -413,29 +413,29 @@ static void tftp_handle_rrq(Slirp *slirp, struct sockaddr_storage *srcsas,
}
spt->block_nr = 0;
tftp_send_next_block(spt, tp);
tftp_send_next_block(spt, &tp->hdr);
}
static void tftp_handle_ack(Slirp *slirp, struct sockaddr_storage *srcsas,
struct tftp_t *tp, int pktlen)
struct tftphdr *hdr)
{
int s;
s = tftp_session_find(slirp, srcsas, tp);
s = tftp_session_find(slirp, srcsas, hdr);
if (s < 0) {
return;
}
tftp_send_next_block(&slirp->tftp_sessions[s], tp);
tftp_send_next_block(&slirp->tftp_sessions[s], hdr);
}
static void tftp_handle_error(Slirp *slirp, struct sockaddr_storage *srcsas,
struct tftp_t *tp, int pktlen)
struct tftphdr *hdr)
{
int s;
s = tftp_session_find(slirp, srcsas, tp);
s = tftp_session_find(slirp, srcsas, hdr);
if (s < 0) {
return;
......@@ -446,23 +446,25 @@ static void tftp_handle_error(Slirp *slirp, struct sockaddr_storage *srcsas,
void tftp_input(struct sockaddr_storage *srcsas, struct mbuf *m)
{
struct tftp_t *tp = mtod_check(m, offsetof(struct tftp_t, x.tp_buf));
struct tftphdr *hdr = mtod_check(m, sizeof(struct tftphdr));
if (tp == NULL) {
if (hdr == NULL) {
return;
}
switch (ntohs(tp->tp_op)) {
switch (ntohs(hdr->tp_op)) {
case TFTP_RRQ:
tftp_handle_rrq(m->slirp, srcsas, tp, m->m_len);
tftp_handle_rrq(m->slirp, srcsas,
mtod(m, struct tftp_t *),
m->m_len);
break;
case TFTP_ACK:
tftp_handle_ack(m->slirp, srcsas, tp, m->m_len);
tftp_handle_ack(m->slirp, srcsas, hdr);
break;
case TFTP_ERROR:
tftp_handle_error(m->slirp, srcsas, tp, m->m_len);
tftp_handle_error(m->slirp, srcsas, hdr);
break;
}
}
src/tftp.h
View file @ 990163cf
......@@ -20,9 +20,13 @@
#define TFTP_FILENAME_MAX 512
#define TFTP_BLOCKSIZE_MAX 1428
struct tftp_t {
struct tftphdr {
struct udphdr udp;
uint16_t tp_op;
} SLIRP_PACKED;
struct tftp_t {
struct tftphdr hdr;
union {
struct {
uint16_t tp_block_nr;
......
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