Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 2 | * |
| 3 | * buffer.c |
| 4 | * |
| 5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 6 | * |
| 7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 8 | * All rights reserved |
| 9 | * |
| 10 | * Created: Sat Mar 18 04:15:33 1995 ylo |
| 11 | * |
| 12 | * Functions for manipulating fifo buffers (that can grow if needed). |
| 13 | * |
| 14 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 15 | |
| 16 | #include "includes.h" |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 17 | RCSID("$Id: buffer.c,v 1.2 1999/11/24 13:26:22 damien Exp $"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 18 | |
| 19 | #include "xmalloc.h" |
| 20 | #include "buffer.h" |
| 21 | #include "ssh.h" |
| 22 | |
| 23 | /* Initializes the buffer structure. */ |
| 24 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 25 | void |
| 26 | buffer_init(Buffer *buffer) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 27 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 28 | buffer->alloc = 4096; |
| 29 | buffer->buf = xmalloc(buffer->alloc); |
| 30 | buffer->offset = 0; |
| 31 | buffer->end = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 32 | } |
| 33 | |
| 34 | /* Frees any memory used for the buffer. */ |
| 35 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 36 | void |
| 37 | buffer_free(Buffer *buffer) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 38 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 39 | memset(buffer->buf, 0, buffer->alloc); |
| 40 | xfree(buffer->buf); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 41 | } |
| 42 | |
| 43 | /* Clears any data from the buffer, making it empty. This does not actually |
| 44 | zero the memory. */ |
| 45 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 46 | void |
| 47 | buffer_clear(Buffer *buffer) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 48 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 49 | buffer->offset = 0; |
| 50 | buffer->end = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 51 | } |
| 52 | |
| 53 | /* Appends data to the buffer, expanding it if necessary. */ |
| 54 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 55 | void |
| 56 | buffer_append(Buffer *buffer, const char *data, unsigned int len) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 57 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 58 | char *cp; |
| 59 | buffer_append_space(buffer, &cp, len); |
| 60 | memcpy(cp, data, len); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 61 | } |
| 62 | |
| 63 | /* Appends space to the buffer, expanding the buffer if necessary. |
| 64 | This does not actually copy the data into the buffer, but instead |
| 65 | returns a pointer to the allocated region. */ |
| 66 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 67 | void |
| 68 | buffer_append_space(Buffer *buffer, char **datap, unsigned int len) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 69 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 70 | /* If the buffer is empty, start using it from the beginning. */ |
| 71 | if (buffer->offset == buffer->end) { |
| 72 | buffer->offset = 0; |
| 73 | buffer->end = 0; |
| 74 | } |
| 75 | restart: |
| 76 | /* If there is enough space to store all data, store it now. */ |
| 77 | if (buffer->end + len < buffer->alloc) { |
| 78 | *datap = buffer->buf + buffer->end; |
| 79 | buffer->end += len; |
| 80 | return; |
| 81 | } |
| 82 | /* If the buffer is quite empty, but all data is at the end, move |
| 83 | the data to the beginning and retry. */ |
| 84 | if (buffer->offset > buffer->alloc / 2) { |
| 85 | memmove(buffer->buf, buffer->buf + buffer->offset, |
| 86 | buffer->end - buffer->offset); |
| 87 | buffer->end -= buffer->offset; |
| 88 | buffer->offset = 0; |
| 89 | goto restart; |
| 90 | } |
| 91 | /* Increase the size of the buffer and retry. */ |
| 92 | buffer->alloc += len + 32768; |
| 93 | buffer->buf = xrealloc(buffer->buf, buffer->alloc); |
| 94 | goto restart; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 95 | } |
| 96 | |
| 97 | /* Returns the number of bytes of data in the buffer. */ |
| 98 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 99 | unsigned int |
| 100 | buffer_len(Buffer *buffer) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 101 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 102 | return buffer->end - buffer->offset; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 103 | } |
| 104 | |
| 105 | /* Gets data from the beginning of the buffer. */ |
| 106 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 107 | void |
| 108 | buffer_get(Buffer *buffer, char *buf, unsigned int len) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 109 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 110 | if (len > buffer->end - buffer->offset) |
| 111 | fatal("buffer_get trying to get more bytes than in buffer"); |
| 112 | memcpy(buf, buffer->buf + buffer->offset, len); |
| 113 | buffer->offset += len; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 114 | } |
| 115 | |
| 116 | /* Consumes the given number of bytes from the beginning of the buffer. */ |
| 117 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 118 | void |
| 119 | buffer_consume(Buffer *buffer, unsigned int bytes) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 120 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 121 | if (bytes > buffer->end - buffer->offset) |
| 122 | fatal("buffer_get trying to get more bytes than in buffer"); |
| 123 | buffer->offset += bytes; |
| 124 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 125 | |
| 126 | /* Consumes the given number of bytes from the end of the buffer. */ |
| 127 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 128 | void |
| 129 | buffer_consume_end(Buffer *buffer, unsigned int bytes) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 130 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 131 | if (bytes > buffer->end - buffer->offset) |
| 132 | fatal("buffer_get trying to get more bytes than in buffer"); |
| 133 | buffer->end -= bytes; |
| 134 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 135 | |
| 136 | /* Returns a pointer to the first used byte in the buffer. */ |
| 137 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 138 | char * |
| 139 | buffer_ptr(Buffer *buffer) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 140 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 141 | return buffer->buf + buffer->offset; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 142 | } |
| 143 | |
| 144 | /* Dumps the contents of the buffer to stderr. */ |
| 145 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 146 | void |
| 147 | buffer_dump(Buffer *buffer) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 148 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame^] | 149 | int i; |
| 150 | unsigned char *ucp = (unsigned char *) buffer->buf; |
| 151 | |
| 152 | for (i = buffer->offset; i < buffer->end; i++) |
| 153 | fprintf(stderr, " %02x", ucp[i]); |
| 154 | fprintf(stderr, "\n"); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 155 | } |