From 907db1f5b9e73a1f088ee4553b729caa2782f36e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Deuc=D0=B5?= <shurd@sasktel.net>
Date: Wed, 27 Dec 2023 12:39:20 -0500
Subject: [PATCH] More refinement and bug fixes...
We can now get the path to the users home directory on the remote
system.
This introduces the use of error fields in the sftpc_state struct,
which should allow result-or-error style stuff pretty easily.
---
src/sftp/sftp.h | 17 ++--
src/sftp/sftp_client.c | 183 ++++++++++++++++++++++++++++++++++++-----
src/sftp/sftp_pkt.c | 12 ++-
src/sftp/sftp_str.c | 2 +-
src/syncterm/ssh.c | 12 ++-
5 files changed, 193 insertions(+), 33 deletions(-)
diff --git a/src/sftp/sftp.h b/src/sftp/sftp.h
index 58a70932b7..5d3e81cd5b 100644
--- a/src/sftp/sftp.h
+++ b/src/sftp/sftp.h
@@ -5,10 +5,10 @@
extern "C" {
#endif
-#include <stdbool.h>
+#include <eventwrap.h>
#include <inttypes.h>
-
-#include "eventwrap.h"
+#include <stdbool.h>
+#include <threadwrap.h>
// draft-ietf-secsh-filexfer-02
@@ -96,8 +96,14 @@ typedef struct sftp_client_state {
xpevent_t recv_event;
sftp_rx_pkt_t rxp;
sftp_tx_pkt_t txp;
- pthread_t thread;
+ sftp_str_t home;
void *cb_data;
+ sftp_str_t err_msg;
+ sftp_str_t err_lang;
+ pthread_t thread;
+ uint32_t id;
+ uint32_t err_id;
+ uint32_t err_code;
} *sftpc_state_t;
/* sftp_pkt.c */
@@ -110,7 +116,7 @@ bool sftp_have_full_pkt(sftp_rx_pkt_t pkt);
void sftp_remove_packet(sftp_rx_pkt_t pkt);
uint32_t sftp_get32(sftp_rx_pkt_t pkt);
uint32_t sftp_get64(sftp_rx_pkt_t pkt);
-sftp_str_t sftp_getstring(sftp_rx_pkt_t pkt, uint8_t **str);
+sftp_str_t sftp_getstring(sftp_rx_pkt_t pkt);
bool sftp_rx_pkt_append(sftp_rx_pkt_t *pkt, uint8_t *inbuf, uint32_t len);
bool sftp_tx_pkt_reset(sftp_tx_pkt_t *pktp);
bool sftp_appendbyte(sftp_tx_pkt_t *pktp, uint8_t u8);
@@ -132,5 +138,6 @@ void sftpc_finish(sftpc_state_t state);
sftpc_state_t sftpc_begin(bool (*send_cb)(uint8_t *buf, size_t len, void *cb_data), void *cb_data);
bool sftpc_init(sftpc_state_t state);
bool sftpc_recv(sftpc_state_t state, uint8_t *buf, uint32_t sz);
+bool sftpc_realpath(sftpc_state_t state, char *path, sftp_str_t *ret);
#endif
diff --git a/src/sftp/sftp_client.c b/src/sftp/sftp_client.c
index e2ce1c253f..965954778e 100644
--- a/src/sftp/sftp_client.c
+++ b/src/sftp/sftp_client.c
@@ -5,6 +5,51 @@
#include "sftp.h"
+static uint32_t
+get32(sftpc_state_t state)
+{
+ return sftp_get32(state->rxp);
+}
+
+static uint64_t
+get64(sftpc_state_t state)
+{
+ return sftp_get64(state->rxp);
+}
+
+static sftp_str_t
+getstring(sftpc_state_t state)
+{
+ return sftp_getstring(state->rxp);
+}
+
+static bool
+appendbyte(sftpc_state_t state, uint8_t u)
+{
+ return sftp_appendbyte(&state->txp, u);
+}
+
+static bool
+append32(sftpc_state_t state, uint32_t u)
+{
+ return sftp_append32(&state->txp, u);
+}
+
+static bool
+append64(sftpc_state_t state, uint64_t u)
+{
+ return sftp_append64(&state->txp, u);
+}
+
+static bool
+appendstring(sftpc_state_t state, sftp_str_t *s)
+{
+ bool ret = sftp_appendstring(&state->txp, *s);
+ free_sftp_str(*s);
+ *s = NULL;
+ return ret;
+}
+
void
sftpc_finish(sftpc_state_t state)
{
@@ -41,42 +86,110 @@ sftpc_begin(bool (*send_cb)(uint8_t *buf, size_t len, void *cb_data), void *cb_d
ret->send_cb = send_cb;
ret->cb_data = cb_data;
ret->thread = pthread_self();
+ ret->id = 0;
+ ret->err_lang = NULL;
+ ret->err_msg = NULL;
return ret;
}
-bool
-sftpc_init(sftpc_state_t state)
+static void
+response_handled(sftpc_state_t state)
+{
+ sftp_remove_packet(state->rxp);
+ if (!sftp_have_full_pkt(state->rxp))
+ ResetEvent(state->recv_event);
+}
+
+static bool
+check_state(sftpc_state_t state)
{
assert(state);
if (!state)
- goto fail;
+ return false;
assert(state->thread == pthread_self());
if (state->thread != pthread_self())
- goto fail;
- if (!sftp_appendbyte(&state->txp, SSH_FXP_INIT))
- goto fail;
- if (!sftp_append32(&state->txp, SFTP_VERSION))
- goto fail;
+ return false;
+ return true;
+}
+
+static bool
+appendheader(sftpc_state_t state, uint8_t type)
+{
+ if (!check_state(state))
+ return false;
+ state->err_code = 0;
+ state->err_id = 0;
+ free_sftp_str(state->err_lang);
+ state->err_lang = NULL;
+ free_sftp_str(state->err_msg);
+ state->err_msg = NULL;
+ if (!sftp_tx_pkt_reset(&state->txp))
+ return false;
+ if (!sftp_appendbyte(&state->txp, type))
+ return false;
+ if (type != SSH_FXP_INIT) {
+ if (!sftp_append32(&state->txp, ++state->id))
+ return false;
+ }
+ return true;
+}
+
+static bool
+get_result(sftpc_state_t state)
+{
uint8_t *txbuf;
size_t txsz;
+
if (!sftp_prep_tx_packet(state->txp, &txbuf, &txsz))
- goto fail;
+ return false;
if (!state->send_cb(txbuf, txsz, state->cb_data))
- goto fail;
- sftp_tx_pkt_reset(&state->txp);
+ return false;
if (WaitForEvent(state->recv_event, INFINITE) != WAIT_OBJECT_0)
- goto fail;
+ return false;
+ if (state->rxp->type != SSH_FXP_VERSION) {
+ uint32_t id = sftp_get32(state->rxp);
+ if (id != state->id) {
+ response_handled(state);
+ return false;
+ }
+ }
+ return true;
+}
+
+static void
+handle_error(sftpc_state_t state)
+{
+ if (state->rxp->type == SSH_FXP_STATUS) {
+ state->err_id = get32(state);
+ state->err_code = get32(state);
+ if (state->err_msg != NULL)
+ free_sftp_str(state->err_msg);
+ state->err_msg = getstring(state);
+ if (state->err_lang != NULL)
+ free_sftp_str(state->err_lang);
+ state->err_lang = getstring(state);
+ }
+ response_handled(state);
+}
+
+bool
+sftpc_init(sftpc_state_t state)
+{
+ if (!appendheader(state, SSH_FXP_INIT))
+ return false;
+ if (!append32(state, SFTP_VERSION))
+ return false;
+ if (!get_result(state))
+ return false;
if (state->rxp->type != SSH_FXP_VERSION)
- goto fail;
- if (sftp_get32(state->rxp) != SFTP_VERSION)
- goto fail;
- sftp_remove_packet(state->rxp);
- if (!sftp_have_full_pkt(state->rxp))
- ResetEvent(state->recv_event);
+ return false;
+ if (get32(state) != SFTP_VERSION) {
+ response_handled(state);
+ return false;
+ }
+ response_handled(state);
+ state->id = 0;
return true;
-fail:
- sftp_tx_pkt_reset(&state->txp);
- return false;
}
bool
@@ -88,3 +201,31 @@ sftpc_recv(sftpc_state_t state, uint8_t *buf, uint32_t sz)
SetEvent(state->recv_event);
return true;
}
+
+bool
+sftpc_realpath(sftpc_state_t state, char *path, sftp_str_t *ret)
+{
+ assert(ret);
+ if (ret == NULL)
+ return false;
+ if (*ret != NULL)
+ return false;
+ if (!appendheader(state, SSH_FXP_REALPATH))
+ return false;
+ sftp_str_t pstr = sftp_strdup(path);
+ if (!appendstring(state, &pstr))
+ return false;
+ if (!get_result(state))
+ return false;
+ if (state->rxp->type == SSH_FXP_NAME) {
+ if (get32(state) != 1) {
+ response_handled(state);
+ return false;
+ }
+ *ret = getstring(state);
+ response_handled(state);
+ return true;
+ }
+ handle_error(state);
+ return false;
+}
diff --git a/src/sftp/sftp_pkt.c b/src/sftp/sftp_pkt.c
index 064ab91a0f..4c2cc82db7 100644
--- a/src/sftp/sftp_pkt.c
+++ b/src/sftp/sftp_pkt.c
@@ -121,6 +121,7 @@ sftp_remove_packet(sftp_rx_pkt_t pkt)
src += sz;
memmove(&pkt->len, src, newsz);
pkt->used = newsz;
+ pkt->cur = 0;
// TODO: realloc() smaller?
return;
}
@@ -161,7 +162,7 @@ sftp_get64(sftp_rx_pkt_t pkt)
* cursor
*/
sftp_str_t
-sftp_getstring(sftp_rx_pkt_t pkt, uint8_t **str)
+sftp_getstring(sftp_rx_pkt_t pkt)
{
assert(pkt);
uint32_t sz = sftp_get32(pkt);
@@ -187,11 +188,13 @@ sftp_rx_pkt_append(sftp_rx_pkt_t *pktp, uint8_t *inbuf, uint32_t len)
size_t old_sz;
size_t new_sz;
uint32_t old_used;
+ uint32_t old_cur;
sftp_rx_pkt_t pkt = *pktp;
if (pkt == NULL) {
old_sz = 0;
old_used = 0;
+ old_cur = 0;
new_sz = offsetof(struct sftp_rx_pkt, len) + len;
}
else {
@@ -211,6 +214,7 @@ sftp_rx_pkt_append(sftp_rx_pkt_t *pktp, uint8_t *inbuf, uint32_t len)
*pktp = new_buf;
pkt = *pktp;
pkt->sz = new_sz;
+ pkt->cur = old_cur;
}
memcpy(&((uint8_t *)&(pkt->len))[old_used], inbuf, len);
pkt->used = old_used + len;
@@ -265,6 +269,8 @@ sftp_tx_pkt_reset(sftp_tx_pkt_t *pktp)
if (pktp == NULL)
return false;
sftp_tx_pkt_t pkt = *pktp;
+ if (pkt == NULL)
+ return true;
pkt->used = 0;
if (pkt->sz == SFTP_MIN_PACKET_ALLOC)
return true;
@@ -310,8 +316,10 @@ sftp_appendstring(sftp_tx_pkt_t *pktp, sftp_str_t s)
{
assert(pktp);
sftp_append32(pktp, s->len);
+ if (!grow_tx(pktp, s->len))
+ return false;
sftp_tx_pkt_t pkt = *pktp;
- memcpy(&pkt->data[pkt->used], (uint8_t *)s->c_str, s->len);
+ memcpy(&(&pkt->type)[pkt->used], (uint8_t *)s->c_str, s->len);
pkt->used += s->len;
return true;
}
diff --git a/src/sftp/sftp_str.c b/src/sftp/sftp_str.c
index 69a641f450..10aa3fa103 100644
--- a/src/sftp/sftp_str.c
+++ b/src/sftp/sftp_str.c
@@ -2,9 +2,9 @@
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
+#include <xpprintf.h>
#include "sftp.h"
-#include "xpprintf.h"
static sftp_str_t
alloc_str(uint32_t len)
diff --git a/src/syncterm/ssh.c b/src/syncterm/ssh.c
index 3c5df27f57..907bd2020e 100644
--- a/src/syncterm/ssh.c
+++ b/src/syncterm/ssh.c
@@ -513,10 +513,14 @@ ssh_connect(struct bbslist *bbs)
}
if (cryptStatusOK(status)) {
sftp_state = sftpc_begin(sftp_send, NULL);
- if (sftp_state == NULL)
- fprintf(stderr, "Failure!\n");
- else if (sftpc_init(sftp_state))
- fprintf(stderr, "Success!\n");
+ if (sftp_state != NULL) {
+ if (sftpc_init(sftp_state)) {
+ sftp_str_t ret = NULL;
+ if (sftpc_realpath(sftp_state, ".", &ret)) {
+ fprintf(stderr, "Home dir: %.*s\n", ret->len, ret->c_str);
+ }
+ }
+ }
}
}
#endif
--
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