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[PATCH v2 1/1] buffer: add and use ssh_buffer_ensure_allocated
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- Subject: [PATCH v2 1/1] buffer: add and use ssh_buffer_ensure_allocated
- From: Pino Toscano <ptoscano@xxxxxxxxxx>
- Reply-to: libssh@xxxxxxxxxx
- Date: Wed, 27 Jun 2018 14:10:26 +0200
- To: libssh@xxxxxxxxxx
Add a small helper for ssh_buffer to ensure that the buffer has a
certain amount of space already preallocated. This can be useful in case
it is known how much data is going to be added to a buffer, to avoid
multiple reallocations.
Make use of it in few places in the library.
Signed-off-by: Pino Toscano <ptoscano@xxxxxxxxxx>
---
include/libssh/buffer.h | 1 +
src/agent.c | 15 +++++
src/buffer.c | 27 +++++++++
src/dh.c | 12 ++++
src/pcap.c | 12 ++++
src/sftp.c | 124 ++++++++++++++++++++++++++++++++++++++++
6 files changed, 191 insertions(+)
diff --git a/include/libssh/buffer.h b/include/libssh/buffer.h
index 14ce5e67..fb8170f4 100644
--- a/include/libssh/buffer.h
+++ b/include/libssh/buffer.h
@@ -47,6 +47,7 @@ int ssh_buffer_add_u8(ssh_buffer buffer, uint8_t data);
int ssh_buffer_add_u16(ssh_buffer buffer, uint16_t data);
int ssh_buffer_add_u32(ssh_buffer buffer, uint32_t data);
int ssh_buffer_add_u64(ssh_buffer buffer, uint64_t data);
+int ssh_buffer_guarantee_allocated(ssh_buffer buffer, uint32_t len);
int ssh_buffer_validate_length(struct ssh_buffer_struct *buffer, size_t len);
diff --git a/src/agent.c b/src/agent.c
index 0b145ff3..e4efb048 100644
--- a/src/agent.c
+++ b/src/agent.c
@@ -536,6 +536,21 @@ ssh_string ssh_agent_sign_data(ssh_session session,
return NULL;
}
+ /*
+ * make sure it already can contain all the expected content:
+ * - 1 x uint8_t
+ * - 2 x uint32_t
+ * - 1 x ssh_string (uint8_t + data)
+ */
+ rc = ssh_buffer_guarantee_allocated(request,
+ sizeof(uint8_t) * 2 +
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(key_blob));
+ if (rc < 0) {
+ ssh_buffer_free(request);
+ return NULL;
+ }
+
/* adds len + blob */
rc = ssh_buffer_add_ssh_string(request, key_blob);
ssh_string_free(key_blob);
diff --git a/src/buffer.c b/src/buffer.c
index 5859e926..4b359378 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -248,6 +248,33 @@ int ssh_buffer_add_data(struct ssh_buffer_struct *buffer, const void *data, uint
return 0;
}
+/**
+ * @brief Ensure the buffer has at least a certain preallocated size.
+ *
+ * @param[in] buffer The buffer to enlarge.
+ *
+ * @param[in] len The length to ensure as allocated.
+ *
+ * @return 0 on success, < 0 on error.
+ */
+int ssh_buffer_guarantee_allocated(struct ssh_buffer_struct *buffer,
+ uint32_t len)
+{
+ buffer_verify(buffer);
+
+ if (buffer->allocated < len) {
+ if (buffer->pos > 0) {
+ buffer_shift(buffer);
+ }
+ if (realloc_buffer(buffer, len) < 0) {
+ return -1;
+ }
+ }
+
+ buffer_verify(buffer);
+ return 0;
+}
+
/**
* @internal
*
diff --git a/src/dh.c b/src/dh.c
index 1c76cf97..eb9dba18 100644
--- a/src/dh.c
+++ b/src/dh.c
@@ -791,6 +791,12 @@ int ssh_hashbufout_add_cookie(ssh_session session) {
return -1;
}
+ if (ssh_buffer_guarantee_allocated(session->out_hashbuf,
+ sizeof(uint8_t) + 16) < 0) {
+ ssh_buffer_reinit(session->out_hashbuf);
+ return -1;
+ }
+
if (ssh_buffer_add_u8(session->out_hashbuf, 20) < 0) {
ssh_buffer_reinit(session->out_hashbuf);
return -1;
@@ -819,6 +825,12 @@ int ssh_hashbufin_add_cookie(ssh_session session, unsigned char *cookie) {
return -1;
}
+ if (ssh_buffer_guarantee_allocated(session->in_hashbuf,
+ sizeof(uint8_t) + 20 + 16) < 0) {
+ ssh_buffer_reinit(session->in_hashbuf);
+ return -1;
+ }
+
if (ssh_buffer_add_u8(session->in_hashbuf, 20) < 0) {
ssh_buffer_reinit(session->in_hashbuf);
return -1;
diff --git a/src/pcap.c b/src/pcap.c
index bfb237ba..3e86a59a 100644
--- a/src/pcap.c
+++ b/src/pcap.c
@@ -165,6 +165,12 @@ int ssh_pcap_file_write_packet(ssh_pcap_file pcap, ssh_buffer packet, uint32_t o
if(header == NULL)
return SSH_ERROR;
gettimeofday(&now,NULL);
+ err = ssh_buffer_guarantee_allocated(header,
+ sizeof(uint32_t) * 4 +
+ ssh_buffer_get_len(packet));
+ if (err < 0) {
+ goto error;
+ }
err = ssh_buffer_add_u32(header,htonl(now.tv_sec));
if (err < 0) {
goto error;
@@ -209,6 +215,12 @@ int ssh_pcap_file_open(ssh_pcap_file pcap, const char *filename){
header=ssh_buffer_new();
if(header==NULL)
return SSH_ERROR;
+ err = ssh_buffer_guarantee_allocated(header,
+ sizeof(uint32_t) * 5 +
+ sizeof(uint16_t) * 2);
+ if (err < 0) {
+ goto error;
+ }
err = ssh_buffer_add_u32(header,htonl(PCAP_MAGIC));
if (err < 0) {
goto error;
diff --git a/src/sftp.c b/src/sftp.c
index 80870d4e..0c196d34 100644
--- a/src/sftp.c
+++ b/src/sftp.c
@@ -318,6 +318,11 @@ sftp_packet sftp_packet_read(sftp_session sftp) {
return NULL;
}
+ r = ssh_buffer_guarantee_allocated(packet->payload, 4);
+ if (r < 0) {
+ ssh_set_error_oom(sftp->session);
+ goto error;
+ }
r=0;
do {
// read from channel until 4 bytes have been read or an error occurs
@@ -355,6 +360,11 @@ sftp_packet sftp_packet_read(sftp_session sftp) {
}
size--;
+ r = ssh_buffer_guarantee_allocated(packet->payload, size);
+ if (r < 0) {
+ ssh_set_error_oom(sftp->session);
+ goto error;
+ }
while (size > 0 && size < UINT_MAX) {
r=ssh_channel_read(sftp->channel,buffer,
sizeof(buffer)>size ? size:sizeof(buffer),0);
@@ -864,6 +874,14 @@ sftp_dir sftp_opendir(sftp_session sftp, const char *path){
}
id = sftp_get_new_id(sftp);
+ if (ssh_buffer_guarantee_allocated(payload,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(path_s)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(payload);
+ ssh_string_free(path_s);
+ return NULL;
+ }
if (ssh_buffer_add_u32(payload, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(payload, path_s) < 0) {
ssh_set_error_oom(sftp->session);
@@ -1392,6 +1410,13 @@ sftp_attributes sftp_readdir(sftp_session sftp, sftp_dir dir) {
return NULL;
}
+ if (ssh_buffer_guarantee_allocated(payload,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(dir->handle)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(payload);
+ return NULL;
+ }
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(payload, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(payload, dir->handle) < 0) {
@@ -1516,6 +1541,14 @@ static int sftp_handle_close(sftp_session sftp, ssh_string handle) {
return -1;
}
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(handle)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ return -1;
+ }
+
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, handle) < 0) {
@@ -1644,6 +1677,14 @@ sftp_file sftp_open(sftp_session sftp, const char *file, int flags,
sftp_flags |= SSH_FXF_APPEND;
}
SSH_LOG(SSH_LOG_PACKET,"Opening file %s with sftp flags %x",file,sftp_flags);
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 4 +
+ ssh_string_len(filename)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ ssh_string_free(filename);
+ return NULL;
+ }
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, filename) < 0) {
@@ -2233,6 +2274,15 @@ int sftp_mkdir(sftp_session sftp, const char *directory, mode_t mode) {
attr.permissions = mode;
attr.flags = SSH_FILEXFER_ATTR_PERMISSIONS;
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(path)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ ssh_string_free(path);
+ return -1;
+ }
+
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, path) < 0 ||
@@ -2399,6 +2449,15 @@ int sftp_setstat(sftp_session sftp, const char *file, sftp_attributes attr) {
return -1;
}
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(path)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ ssh_string_free(path);
+ return -1;
+ }
+
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, path) < 0 ||
@@ -2616,6 +2675,15 @@ char *sftp_readlink(sftp_session sftp, const char *path) {
return NULL;
}
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(path_s)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ ssh_string_free(path_s);
+ return NULL;
+ }
+
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, path_s) < 0) {
@@ -2743,6 +2811,17 @@ sftp_statvfs_t sftp_statvfs(sftp_session sftp, const char *path) {
return NULL;
}
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 3 +
+ ssh_string_len(ext) +
+ ssh_string_len(pathstr)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ ssh_string_free(ext);
+ ssh_string_free(pathstr);
+ return NULL;
+ }
+
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, ext) < 0 ||
@@ -2823,6 +2902,15 @@ int sftp_fsync(sftp_file file)
goto done;
}
+ rc = ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 3 +
+ ssh_string_len(ext) +
+ ssh_string_len(file->handle));
+ if (rc < 0) {
+ ssh_set_error_oom(sftp->session);
+ goto done;
+ }
+
id = sftp_get_new_id(sftp);
rc = ssh_buffer_add_u32(buffer, htonl(id));
if (rc < 0) {
@@ -2934,6 +3022,16 @@ sftp_statvfs_t sftp_fstatvfs(sftp_file file) {
return NULL;
}
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 3 +
+ ssh_string_len(ext) +
+ ssh_string_len(file->handle)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ ssh_string_free(ext);
+ return NULL;
+ }
+
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, ext) < 0 ||
@@ -3023,6 +3121,15 @@ char *sftp_canonicalize_path(sftp_session sftp, const char *path) {
return NULL;
}
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(pathstr)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ ssh_string_free(pathstr);
+ return NULL;
+ }
+
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, pathstr) < 0) {
@@ -3106,6 +3213,15 @@ static sftp_attributes sftp_xstat(sftp_session sftp, const char *path,
return NULL;
}
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(pathstr)) < 0) {
+ ssh_set_error_oom(sftp->session);
+ ssh_buffer_free(buffer);
+ ssh_string_free(pathstr);
+ return NULL;
+ }
+
id = sftp_get_new_id(sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, pathstr) < 0) {
@@ -3173,6 +3289,14 @@ sftp_attributes sftp_fstat(sftp_file file) {
return NULL;
}
+ if (ssh_buffer_guarantee_allocated(buffer,
+ sizeof(uint32_t) * 2 +
+ ssh_string_len(file->handle)) < 0) {
+ ssh_set_error_oom(file->sftp->session);
+ ssh_buffer_free(buffer);
+ return NULL;
+ }
+
id = sftp_get_new_id(file->sftp);
if (ssh_buffer_add_u32(buffer, htonl(id)) < 0 ||
ssh_buffer_add_ssh_string(buffer, file->handle) < 0) {
--
2.17.1
| [PATCH v2 0/1] RFC: add ssh_buffer_ensure_allocated | Pino Toscano <ptoscano@xxxxxxxxxx> |