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authorAndreas Schneider <asn@cynapses.org>2010-09-06 14:28:38 +0200
committerAndreas Schneider <asn@cynapses.org>2010-09-06 14:28:38 +0200
commitf7842e3a4b9acea2126ff725f993c299aef0e6db (patch)
tree18239f819a5edbcfc7f2961c48f3f9297314ef22 /src/buffer.c
parent38421403d2dc45636e597f2a909daa6ae31976de (diff)
downloadlibssh-f7842e3a4b9acea2126ff725f993c299aef0e6db.tar.gz
libssh-f7842e3a4b9acea2126ff725f993c299aef0e6db.tar.xz
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misc: Rename libssh/ to src/
Diffstat (limited to 'src/buffer.c')
-rw-r--r--src/buffer.c578
1 files changed, 578 insertions, 0 deletions
diff --git a/src/buffer.c b/src/buffer.c
new file mode 100644
index 00000000..80c99560
--- /dev/null
+++ b/src/buffer.c
@@ -0,0 +1,578 @@
+/*
+ * buffer.c - buffer functions
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2003-2009 by Aris Adamantiadis
+ *
+ * The SSH Library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 of the License, or (at your
+ * option) any later version.
+ *
+ * The SSH Library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with the SSH Library; see the file COPYING. If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef _WIN32
+#include <arpa/inet.h>
+#endif
+
+#include "libssh/priv.h"
+#include "libssh/buffer.h"
+
+/**
+ * @defgroup libssh_buffer The SSH buffer functions.
+ * @ingroup libssh
+ *
+ * Functions to handle SSH buffers.
+ *
+ * @{
+ */
+
+
+#ifdef DEBUG_BUFFER
+/**
+ * @internal
+ *
+ * @brief Check that preconditions and postconditions are valid.
+ *
+ * @param[in] buf The buffer to check.
+ */
+static void buffer_verify(struct buffer_struct *buf){
+ int doabort=0;
+ if(buf->data == NULL)
+ return;
+ if(buf->used > buf->allocated){
+ fprintf(stderr,"Buffer error : allocated %u, used %u\n",buf->allocated, buf->used);
+ doabort=1;
+ }
+ if(buf->pos > buf->used){
+ fprintf(stderr,"Buffer error : position %u, used %u\n",buf->pos, buf->used);
+ doabort=1;
+ }
+ if(buf->pos > buf->allocated){
+ fprintf(stderr,"Buffer error : position %u, allocated %u\n",buf->pos, buf->allocated);
+ doabort=1;
+ }
+ if(doabort)
+ abort();
+}
+
+#else
+#define buffer_verify(x)
+#endif
+
+/**
+ * @brief Create a new SSH buffer.
+ *
+ * @return A newly initialized SSH buffer, NULL on error.
+ */
+struct ssh_buffer_struct *ssh_buffer_new(void) {
+ struct ssh_buffer_struct *buf = malloc(sizeof(struct ssh_buffer_struct));
+
+ if (buf == NULL) {
+ return NULL;
+ }
+ memset(buf, 0, sizeof(struct ssh_buffer_struct));
+ buffer_verify(buf);
+ return buf;
+}
+
+/**
+ * @brief Deallocate a SSH buffer.
+ *
+ * \param[in] buffer The buffer to free.
+ */
+void ssh_buffer_free(struct ssh_buffer_struct *buffer) {
+ if (buffer == NULL) {
+ return;
+ }
+ buffer_verify(buffer);
+
+ if (buffer->data) {
+ /* burn the data */
+ memset(buffer->data, 0, buffer->allocated);
+ SAFE_FREE(buffer->data);
+ }
+ memset(buffer, 'X', sizeof(*buffer));
+ SAFE_FREE(buffer);
+}
+
+static int realloc_buffer(struct ssh_buffer_struct *buffer, int needed) {
+ int smallest = 1;
+ char *new = NULL;
+ buffer_verify(buffer);
+ /* Find the smallest power of two which is greater or equal to needed */
+ while(smallest < needed) {
+ smallest <<= 1;
+ }
+ needed = smallest;
+ new = realloc(buffer->data, needed);
+ if (new == NULL) {
+ return -1;
+ }
+ buffer->data = new;
+ buffer->allocated = needed;
+ buffer_verify(buffer);
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Reinitialize a SSH buffer.
+ *
+ * @param[in] buffer The buffer to reinitialize.
+ *
+ * @return 0 on success, < 0 on error.
+ */
+int buffer_reinit(struct ssh_buffer_struct *buffer) {
+ buffer_verify(buffer);
+ memset(buffer->data, 0, buffer->used);
+ buffer->used = 0;
+ buffer->pos = 0;
+ if(buffer->allocated > 127) {
+ if (realloc_buffer(buffer, 127) < 0) {
+ return -1;
+ }
+ }
+ buffer_verify(buffer);
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Add data at the tail of a buffer.
+ *
+ * @param[in] buffer The buffer to add the data.
+ *
+ * @param[in] data A pointer to the data to add.
+ *
+ * @param[in] len The length of the data to add.
+ *
+ * @return 0 on success, < 0 on error.
+ */
+int buffer_add_data(struct ssh_buffer_struct *buffer, const void *data, uint32_t len) {
+ buffer_verify(buffer);
+ if (buffer->allocated < (buffer->used + len)) {
+ if (realloc_buffer(buffer, buffer->used + len) < 0) {
+ return -1;
+ }
+ }
+
+ memcpy(buffer->data+buffer->used, data, len);
+ buffer->used+=len;
+ buffer_verify(buffer);
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Add a SSH string to the tail of a buffer.
+ *
+ * @param[in] buffer The buffer to add the string.
+ *
+ * @param[in] string The SSH String to add.
+ *
+ * @return 0 on success, < 0 on error.
+ */
+int buffer_add_ssh_string(struct ssh_buffer_struct *buffer,
+ struct ssh_string_struct *string) {
+ uint32_t len = 0;
+
+ len = ssh_string_len(string);
+ if (buffer_add_data(buffer, string, len + sizeof(uint32_t)) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Add a 32 bits unsigned integer to the tail of a buffer.
+ *
+ * @param[in] buffer The buffer to add the integer.
+ *
+ * @param[in] data The 32 bits integer to add.
+ *
+ * @return 0 on success, -1 on error.
+ */
+int buffer_add_u32(struct ssh_buffer_struct *buffer,uint32_t data){
+ if (buffer_add_data(buffer, &data, sizeof(data)) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Add a 16 bits unsigned integer to the tail of a buffer.
+ *
+ * @param[in] buffer The buffer to add the integer.
+ *
+ * @param[in] data The 16 bits integer to add.
+ *
+ * @return 0 on success, -1 on error.
+ */
+int buffer_add_u16(struct ssh_buffer_struct *buffer,uint16_t data){
+ if (buffer_add_data(buffer, &data, sizeof(data)) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Add a 64 bits unsigned integer to the tail of a buffer.
+ *
+ * @param[in] buffer The buffer to add the integer.
+ *
+ * @param[in] data The 64 bits integer to add.
+ *
+ * @return 0 on success, -1 on error.
+ */
+int buffer_add_u64(struct ssh_buffer_struct *buffer, uint64_t data){
+ if (buffer_add_data(buffer, &data, sizeof(data)) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Add a 8 bits unsigned integer to the tail of a buffer.
+ *
+ * @param[in] buffer The buffer to add the integer.
+ *
+ * @param[in] data The 8 bits integer to add.
+ *
+ * @return 0 on success, -1 on error.
+ */
+int buffer_add_u8(struct ssh_buffer_struct *buffer,uint8_t data){
+ if (buffer_add_data(buffer, &data, sizeof(uint8_t)) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Add data at the head of a buffer.
+ *
+ * @param[in] buffer The buffer to add the data.
+ *
+ * @param[in] data The data to prepend.
+ *
+ * @param[in] len The length of data to prepend.
+ *
+ * @return 0 on success, -1 on error.
+ */
+int buffer_prepend_data(struct ssh_buffer_struct *buffer, const void *data,
+ uint32_t len) {
+ buffer_verify(buffer);
+ if (buffer->allocated < (buffer->used + len)) {
+ if (realloc_buffer(buffer, buffer->used + len) < 0) {
+ return -1;
+ }
+ }
+ memmove(buffer->data + len, buffer->data, buffer->used);
+ memcpy(buffer->data, data, len);
+ buffer->used += len;
+ buffer_verify(buffer);
+ return 0;
+}
+
+/**
+ * @internal
+ *
+ * @brief Append data from a buffer to the tail of another buffer.
+ *
+ * @param[in] buffer The destination buffer.
+ *
+ * @param[in] source The source buffer to append. It doesn't take the
+ * position of the buffer into account.
+ *
+ * @return 0 on success, -1 on error.
+ */
+int buffer_add_buffer(struct ssh_buffer_struct *buffer,
+ struct ssh_buffer_struct *source) {
+ if (buffer_add_data(buffer, ssh_buffer_get_begin(source), ssh_buffer_get_len(source)) < 0) {
+ return -1;
+ }
+
+ return 0;
+}
+
+/**
+ * @brief Get a pointer on the head of a buffer.
+ *
+ * @param[in] buffer The buffer to get the head pointer.
+ *
+ * @return A data pointer on the head. It doesn't take the position
+ * into account.
+ *
+ * @warning Don't expect data to be nul-terminated.
+ *
+ * @see buffer_get_rest()
+ * @see buffer_get_len()
+ */
+void *ssh_buffer_get_begin(struct ssh_buffer_struct *buffer){
+ return buffer->data;
+}
+
+/**
+ * @internal
+ *
+ * @brief Get a pointer to the head of a buffer at the current position.
+ *
+ * @param[in] buffer The buffer to get the head pointer.
+ *
+ * @return A pointer to the data from current position.
+ *
+ * @see buffer_get_rest_len()
+ * @see buffer_get()
+ */
+void *buffer_get_rest(struct ssh_buffer_struct *buffer){
+ return buffer->data + buffer->pos;
+}
+
+/**
+ * @brief Get the length of the buffer, not counting position.
+ *
+ * @param[in] buffer The buffer to get the length from.
+ *
+ * @return The length of the buffer.
+ *
+ * @see buffer_get()
+ */
+uint32_t ssh_buffer_get_len(struct ssh_buffer_struct *buffer){
+ return buffer->used;
+}
+
+/**
+ * @internal
+ *
+ * @brief Get the length of the buffer from the current position.
+ *
+ * @param[in] buffer The buffer to get the length from.
+ *
+ * @return The length of the buffer.
+ *
+ * @see buffer_get_rest()
+ */
+uint32_t buffer_get_rest_len(struct ssh_buffer_struct *buffer){
+ buffer_verify(buffer);
+ return buffer->used - buffer->pos;
+}
+
+/**
+ * @internal
+ *
+ * @brief Advance the position in the buffer.
+ *
+ * This has effect to "eat" bytes at head of the buffer.
+ *
+ * @param[in] buffer The buffer to advance the position.
+ *
+ * @param[in] len The number of bytes to eat.
+ *
+ * @return The new size of the buffer.
+ */
+uint32_t buffer_pass_bytes(struct ssh_buffer_struct *buffer, uint32_t len){
+ buffer_verify(buffer);
+ if(buffer->used < buffer->pos+len)
+ return 0;
+ buffer->pos+=len;
+ /* if the buffer is empty after having passed the whole bytes into it, we can clean it */
+ if(buffer->pos==buffer->used){
+ buffer->pos=0;
+ buffer->used=0;
+ }
+ buffer_verify(buffer);
+ return len;
+}
+
+/**
+ * @internal
+ *
+ * @brief Cut the end of the buffer.
+ *
+ * @param[in] buffer The buffer to cut.
+ *
+ * @param[in] len The number of bytes to remove from the tail.
+ *
+ * @return The new size of the buffer.
+ */
+uint32_t buffer_pass_bytes_end(struct ssh_buffer_struct *buffer, uint32_t len){
+ buffer_verify(buffer);
+ if(buffer->used < buffer->pos + len)
+ return 0;
+ buffer->used-=len;
+ buffer_verify(buffer);
+ return len;
+}
+
+/**
+ * @internal
+ *
+ * @brief Get the remaining data out of the buffer and adjust the read pointer.
+ *
+ * @param[in] buffer The buffer to read.
+ *
+ * @param[in] data The data buffer where to store the data.
+ *
+ * @param[in] len The length to read from the buffer.
+ *
+ * @returns 0 if there is not enough data in buffer, len otherwise.
+ */
+uint32_t buffer_get_data(struct ssh_buffer_struct *buffer, void *data, uint32_t len){
+ /*
+ * Check for a integer overflow first, then check if not enough data is in
+ * the buffer.
+ */
+ if (buffer->pos + len < len || buffer->pos + len > buffer->used) {
+ return 0;
+ }
+ memcpy(data,buffer->data+buffer->pos,len);
+ buffer->pos+=len;
+ return len; /* no yet support for partial reads (is it really needed ?? ) */
+}
+
+/**
+ * @internal
+ *
+ * @brief Get a 8 bits unsigned int out of the buffer and adjusts the read
+ * pointer.
+ *
+ * @param[in] buffer The buffer to read.
+ *
+ * @param[in] data A pointer to a uint8_t where to store the data.
+ *
+ * @returns 0 if there is not enough data in buffer, 1 otherwise.
+ */
+int buffer_get_u8(struct ssh_buffer_struct *buffer, uint8_t *data){
+ return buffer_get_data(buffer,data,sizeof(uint8_t));
+}
+
+/** \internal
+ * \brief gets a 32 bits unsigned int out of the buffer. Adjusts the read pointer.
+ * \param buffer Buffer to read
+ * \param data pointer to a uint32_t where to store the data
+ * \returns 0 if there is not enough data in buffer
+ * \returns 4 otherwise.
+ */
+int buffer_get_u32(struct ssh_buffer_struct *buffer, uint32_t *data){
+ return buffer_get_data(buffer,data,sizeof(uint32_t));
+}
+/**
+ * @internal
+ *
+ * @brief Get a 64 bits unsigned int out of the buffer and adjusts the read
+ * pointer.
+ *
+ * @param[in] buffer The buffer to read.
+ *
+ * @param[in] data A pointer to a uint64_t where to store the data.
+ *
+ * @returns 0 if there is not enough data in buffer, 8 otherwise.
+ */
+int buffer_get_u64(struct ssh_buffer_struct *buffer, uint64_t *data){
+ return buffer_get_data(buffer,data,sizeof(uint64_t));
+}
+
+/**
+ * @internal
+ *
+ * @brief Get a SSH String out of the buffer and adjusts the read pointer.
+ *
+ * @param[in] buffer The buffer to read.
+ *
+ * @returns The SSH String, NULL on error.
+ */
+struct ssh_string_struct *buffer_get_ssh_string(struct ssh_buffer_struct *buffer) {
+ uint32_t stringlen;
+ uint32_t hostlen;
+ struct ssh_string_struct *str = NULL;
+
+ if (buffer_get_u32(buffer, &stringlen) == 0) {
+ return NULL;
+ }
+ hostlen = ntohl(stringlen);
+ /* verify if there is enough space in buffer to get it */
+ if ((buffer->pos + hostlen) > buffer->used) {
+ return NULL; /* it is indeed */
+ }
+ str = ssh_string_new(hostlen);
+ if (str == NULL) {
+ return NULL;
+ }
+ if (buffer_get_data(buffer, ssh_string_data(str), hostlen) != hostlen) {
+ /* should never happen */
+ SAFE_FREE(str);
+ return NULL;
+ }
+
+ return str;
+}
+
+/**
+ * @internal
+ *
+ * @brief Get a mpint out of the buffer and adjusts the read pointer.
+ *
+ * @note This function is SSH-1 only.
+ *
+ * @param[in] buffer The buffer to read.
+ *
+ * @returns The SSH String containing the mpint, NULL on error.
+ */
+struct ssh_string_struct *buffer_get_mpint(struct ssh_buffer_struct *buffer) {
+ uint16_t bits;
+ uint32_t len;
+ struct ssh_string_struct *str = NULL;
+
+ if (buffer_get_data(buffer, &bits, sizeof(uint16_t)) != sizeof(uint16_t)) {
+ return NULL;
+ }
+ bits = ntohs(bits);
+ len = (bits + 7) / 8;
+ if ((buffer->pos + len) > buffer->used) {
+ return NULL;
+ }
+ str = ssh_string_new(len);
+ if (str == NULL) {
+ return NULL;
+ }
+ if (buffer_get_data(buffer, ssh_string_data(str), len) != len) {
+ SAFE_FREE(str);
+ return NULL;
+ }
+ return str;
+}
+
+/** @} */
+
+/* vim: set ts=4 sw=4 et cindent: */