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249 lines
8.0 KiB
249 lines
8.0 KiB
From c8665ebbdadb72f7c2cb74b9704f68704c13653b Mon Sep 17 00:00:00 2001 |
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From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com> |
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Date: Fri, 4 Jun 2021 20:01:20 +0400 |
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Subject: [PATCH 6/7] tftp: introduce a header structure |
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MIME-Version: 1.0 |
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Content-Type: text/plain; charset=UTF-8 |
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Content-Transfer-Encoding: 8bit |
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Instead of using a composed structure and potentially reading past the |
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incoming buffer, use a different structure for the header. |
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Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> |
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(cherry picked from commit 990163cf3ac86b7875559f49602c4d76f46f6f30) |
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--- |
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src/tftp.c | 60 ++++++++++++++++++++++++++++-------------------------- |
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src/tftp.h | 6 +++++- |
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2 files changed, 36 insertions(+), 30 deletions(-) |
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diff --git a/src/tftp.c b/src/tftp.c |
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index e06911d..a19c889 100644 |
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--- a/src/tftp.c |
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+++ b/src/tftp.c |
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@@ -50,7 +50,7 @@ static void tftp_session_terminate(struct tftp_session *spt) |
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} |
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static int tftp_session_allocate(Slirp *slirp, struct sockaddr_storage *srcsas, |
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- struct tftp_t *tp) |
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+ struct tftphdr *hdr) |
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{ |
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struct tftp_session *spt; |
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int k; |
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@@ -75,7 +75,7 @@ found: |
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memcpy(&spt->client_addr, srcsas, sockaddr_size(srcsas)); |
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spt->fd = -1; |
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spt->block_size = 512; |
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- spt->client_port = tp->udp.uh_sport; |
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+ spt->client_port = hdr->udp.uh_sport; |
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spt->slirp = slirp; |
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tftp_session_update(spt); |
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@@ -84,7 +84,7 @@ found: |
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} |
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static int tftp_session_find(Slirp *slirp, struct sockaddr_storage *srcsas, |
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- struct tftp_t *tp) |
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+ struct tftphdr *hdr) |
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{ |
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struct tftp_session *spt; |
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int k; |
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@@ -94,7 +94,7 @@ static int tftp_session_find(Slirp *slirp, struct sockaddr_storage *srcsas, |
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if (tftp_session_in_use(spt)) { |
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if (sockaddr_equal(&spt->client_addr, srcsas)) { |
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- if (spt->client_port == tp->udp.uh_sport) { |
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+ if (spt->client_port == hdr->udp.uh_sport) { |
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return k; |
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} |
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} |
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@@ -148,13 +148,13 @@ static struct tftp_t *tftp_prep_mbuf_data(struct tftp_session *spt, |
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} |
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static void tftp_udp_output(struct tftp_session *spt, struct mbuf *m, |
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- struct tftp_t *recv_tp) |
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+ struct tftphdr *hdr) |
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{ |
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if (spt->client_addr.ss_family == AF_INET6) { |
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struct sockaddr_in6 sa6, da6; |
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sa6.sin6_addr = spt->slirp->vhost_addr6; |
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- sa6.sin6_port = recv_tp->udp.uh_dport; |
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+ sa6.sin6_port = hdr->udp.uh_dport; |
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da6.sin6_addr = ((struct sockaddr_in6 *)&spt->client_addr)->sin6_addr; |
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da6.sin6_port = spt->client_port; |
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@@ -163,7 +163,7 @@ static void tftp_udp_output(struct tftp_session *spt, struct mbuf *m, |
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struct sockaddr_in sa4, da4; |
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sa4.sin_addr = spt->slirp->vhost_addr; |
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- sa4.sin_port = recv_tp->udp.uh_dport; |
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+ sa4.sin_port = hdr->udp.uh_dport; |
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da4.sin_addr = ((struct sockaddr_in *)&spt->client_addr)->sin_addr; |
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da4.sin_port = spt->client_port; |
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@@ -185,14 +185,14 @@ static int tftp_send_oack(struct tftp_session *spt, const char *keys[], |
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tp = tftp_prep_mbuf_data(spt, m); |
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- tp->tp_op = htons(TFTP_OACK); |
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+ tp->hdr.tp_op = htons(TFTP_OACK); |
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for (i = 0; i < nb; i++) { |
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n += slirp_fmt0(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%s", keys[i]); |
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n += slirp_fmt0(tp->x.tp_buf + n, sizeof(tp->x.tp_buf) - n, "%u", values[i]); |
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} |
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- m->m_len = G_SIZEOF_MEMBER(struct tftp_t, tp_op) + n; |
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- tftp_udp_output(spt, m, recv_tp); |
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+ m->m_len = G_SIZEOF_MEMBER(struct tftp_t, hdr.tp_op) + n; |
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+ tftp_udp_output(spt, m, &recv_tp->hdr); |
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return 0; |
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} |
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@@ -213,21 +213,21 @@ static void tftp_send_error(struct tftp_session *spt, uint16_t errorcode, |
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tp = tftp_prep_mbuf_data(spt, m); |
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- tp->tp_op = htons(TFTP_ERROR); |
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+ tp->hdr.tp_op = htons(TFTP_ERROR); |
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tp->x.tp_error.tp_error_code = htons(errorcode); |
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slirp_pstrcpy((char *)tp->x.tp_error.tp_msg, sizeof(tp->x.tp_error.tp_msg), |
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msg); |
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m->m_len = sizeof(struct tftp_t) - (TFTP_BLOCKSIZE_MAX + 2) + 3 + |
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strlen(msg) - sizeof(struct udphdr); |
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- tftp_udp_output(spt, m, recv_tp); |
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+ tftp_udp_output(spt, m, &recv_tp->hdr); |
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out: |
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tftp_session_terminate(spt); |
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} |
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static void tftp_send_next_block(struct tftp_session *spt, |
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- struct tftp_t *recv_tp) |
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+ struct tftphdr *hdr) |
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{ |
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struct mbuf *m; |
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struct tftp_t *tp; |
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@@ -241,7 +241,7 @@ static void tftp_send_next_block(struct tftp_session *spt, |
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tp = tftp_prep_mbuf_data(spt, m); |
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- tp->tp_op = htons(TFTP_DATA); |
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+ tp->hdr.tp_op = htons(TFTP_DATA); |
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tp->x.tp_data.tp_block_nr = htons((spt->block_nr + 1) & 0xffff); |
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nobytes = tftp_read_data(spt, spt->block_nr, tp->x.tp_data.tp_buf, |
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@@ -259,7 +259,7 @@ static void tftp_send_next_block(struct tftp_session *spt, |
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m->m_len = sizeof(struct tftp_t) - (TFTP_BLOCKSIZE_MAX - nobytes) - |
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sizeof(struct udphdr); |
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- tftp_udp_output(spt, m, recv_tp); |
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+ tftp_udp_output(spt, m, hdr); |
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if (nobytes == spt->block_size) { |
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tftp_session_update(spt); |
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@@ -282,12 +282,12 @@ static void tftp_handle_rrq(Slirp *slirp, struct sockaddr_storage *srcsas, |
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int nb_options = 0; |
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/* check if a session already exists and if so terminate it */ |
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- s = tftp_session_find(slirp, srcsas, tp); |
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+ s = tftp_session_find(slirp, srcsas, &tp->hdr); |
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if (s >= 0) { |
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tftp_session_terminate(&slirp->tftp_sessions[s]); |
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} |
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- s = tftp_session_allocate(slirp, srcsas, tp); |
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+ s = tftp_session_allocate(slirp, srcsas, &tp->hdr); |
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if (s < 0) { |
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return; |
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@@ -413,29 +413,29 @@ static void tftp_handle_rrq(Slirp *slirp, struct sockaddr_storage *srcsas, |
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} |
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spt->block_nr = 0; |
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- tftp_send_next_block(spt, tp); |
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+ tftp_send_next_block(spt, &tp->hdr); |
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} |
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static void tftp_handle_ack(Slirp *slirp, struct sockaddr_storage *srcsas, |
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- struct tftp_t *tp, int pktlen) |
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+ struct tftphdr *hdr) |
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{ |
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int s; |
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- s = tftp_session_find(slirp, srcsas, tp); |
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+ s = tftp_session_find(slirp, srcsas, hdr); |
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if (s < 0) { |
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return; |
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} |
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- tftp_send_next_block(&slirp->tftp_sessions[s], tp); |
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+ tftp_send_next_block(&slirp->tftp_sessions[s], hdr); |
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} |
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static void tftp_handle_error(Slirp *slirp, struct sockaddr_storage *srcsas, |
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- struct tftp_t *tp, int pktlen) |
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+ struct tftphdr *hdr) |
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{ |
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int s; |
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- s = tftp_session_find(slirp, srcsas, tp); |
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+ s = tftp_session_find(slirp, srcsas, hdr); |
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if (s < 0) { |
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return; |
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@@ -446,23 +446,25 @@ static void tftp_handle_error(Slirp *slirp, struct sockaddr_storage *srcsas, |
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void tftp_input(struct sockaddr_storage *srcsas, struct mbuf *m) |
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{ |
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- struct tftp_t *tp = mtod_check(m, offsetof(struct tftp_t, x.tp_buf)); |
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+ struct tftphdr *hdr = mtod_check(m, sizeof(struct tftphdr)); |
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- if (tp == NULL) { |
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+ if (hdr == NULL) { |
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return; |
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} |
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- switch (ntohs(tp->tp_op)) { |
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+ switch (ntohs(hdr->tp_op)) { |
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case TFTP_RRQ: |
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- tftp_handle_rrq(m->slirp, srcsas, tp, m->m_len); |
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+ tftp_handle_rrq(m->slirp, srcsas, |
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+ mtod(m, struct tftp_t *), |
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+ m->m_len); |
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break; |
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case TFTP_ACK: |
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- tftp_handle_ack(m->slirp, srcsas, tp, m->m_len); |
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+ tftp_handle_ack(m->slirp, srcsas, hdr); |
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break; |
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case TFTP_ERROR: |
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- tftp_handle_error(m->slirp, srcsas, tp, m->m_len); |
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+ tftp_handle_error(m->slirp, srcsas, hdr); |
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break; |
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} |
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} |
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diff --git a/src/tftp.h b/src/tftp.h |
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index 6d75478..cafab03 100644 |
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--- a/src/tftp.h |
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+++ b/src/tftp.h |
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@@ -20,9 +20,13 @@ |
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#define TFTP_FILENAME_MAX 512 |
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#define TFTP_BLOCKSIZE_MAX 1428 |
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-struct tftp_t { |
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+struct tftphdr { |
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struct udphdr udp; |
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uint16_t tp_op; |
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+} SLIRP_PACKED; |
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+ |
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+struct tftp_t { |
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+ struct tftphdr hdr; |
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union { |
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struct { |
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uint16_t tp_block_nr; |
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-- |
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2.29.0 |
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