1 /* $OpenBSD: field.c,v 1.19 2005/11/15 21:49:04 cloder Exp $ */ 2 /* $EOM: field.c,v 1.11 2000/02/20 19:58:37 niklas Exp $ */ 3 4 /* 5 * Copyright (c) 1998, 1999 Niklas Hallqvist. All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 /* 29 * This code was written under funding by Ericsson Radio Systems. 30 */ 31 32 #include <stdio.h> 33 #include <stdlib.h> 34 #include <string.h> 35 36 #include "constants.h" 37 #include "field.h" 38 #include "log.h" 39 #include "util.h" 40 41 static char *field_debug_raw(u_int8_t *, size_t, struct constant_map **); 42 static char *field_debug_num(u_int8_t *, size_t, struct constant_map **); 43 static char *field_debug_mask(u_int8_t *, size_t, struct constant_map **); 44 static char *field_debug_ign(u_int8_t *, size_t, struct constant_map **); 45 static char *field_debug_cst(u_int8_t *, size_t, struct constant_map **); 46 47 /* Contents must match the enum in struct field. */ 48 static char *(*decode_field[]) (u_int8_t *, size_t, 49 struct constant_map **) = { 50 field_debug_raw, 51 field_debug_num, 52 field_debug_mask, 53 field_debug_ign, 54 field_debug_cst 55 }; 56 57 /* 58 * Return a string showing the hexadecimal contents of the LEN-sized buffer 59 * BUF. MAPS should be zero and is only here because the API requires it. 60 */ 61 static char * 62 field_debug_raw(u_int8_t *buf, size_t len, struct constant_map **maps) 63 { 64 return raw2hex(buf, len); 65 } 66 67 /* 68 * Convert the unsigned LEN-sized number at BUF of network byteorder to a 69 * 32-bit unsigned integer of host byteorder pointed to by VAL. 70 */ 71 static int 72 extract_val(u_int8_t *buf, size_t len, u_int32_t *val) 73 { 74 switch (len) { 75 case 1: 76 *val = *buf; 77 break; 78 case 2: 79 *val = decode_16(buf); 80 break; 81 case 4: 82 *val = decode_32(buf); 83 break; 84 default: 85 return -1; 86 } 87 return 0; 88 } 89 90 /* 91 * Return a textual representation of the unsigned number pointed to by BUF 92 * which is LEN octets long. MAPS should be zero and is only here because 93 * the API requires it. 94 */ 95 static char * 96 field_debug_num(u_int8_t *buf, size_t len, struct constant_map **maps) 97 { 98 char *retval; 99 u_int32_t val; 100 101 if (extract_val(buf, len, &val)) 102 return 0; 103 /* 3 decimal digits are enough to represent each byte. */ 104 asprintf(&retval, "%u", val); 105 return retval; 106 } 107 108 /* 109 * Return the symbolic names of the flags pointed to by BUF which is LEN 110 * octets long, using the constant maps MAPS. 111 */ 112 static char * 113 field_debug_mask(u_int8_t *buf, size_t len, struct constant_map **maps) 114 { 115 u_int32_t val; 116 u_int32_t bit; 117 char *retval, *new_buf, *name; 118 size_t buf_sz; 119 120 if (extract_val(buf, len, &val)) 121 return 0; 122 123 /* Size for brackets, two spaces and a NUL terminator. */ 124 buf_sz = 4; 125 retval = malloc(buf_sz); 126 if (!retval) 127 return 0; 128 129 strlcpy(retval, "[ ", buf_sz); 130 for (bit = 1; bit; bit <<= 1) { 131 if (val & bit) { 132 name = constant_name_maps(maps, bit); 133 buf_sz += strlen(name) + 1; 134 new_buf = realloc(retval, buf_sz); 135 if (!new_buf) { 136 free(retval); 137 return 0; 138 } 139 retval = new_buf; 140 strlcat(retval, name, buf_sz); 141 strlcat(retval, " ", buf_sz); 142 } 143 } 144 strlcat(retval, "]", buf_sz); 145 return retval; 146 } 147 148 /* 149 * Just a dummy needed to skip the unused LEN sized space at BUF. MAPS 150 * should be zero and is only here because the API requires it. 151 */ 152 static char * 153 field_debug_ign(u_int8_t *buf, size_t len, struct constant_map **maps) 154 { 155 return 0; 156 } 157 158 /* 159 * Return the symbolic name of a constant pointed to by BUF which is LEN 160 * octets long, using the constant maps MAPS. 161 */ 162 static char * 163 field_debug_cst(u_int8_t *buf, size_t len, struct constant_map **maps) 164 { 165 u_int32_t val; 166 167 if (extract_val(buf, len, &val)) 168 return 0; 169 170 return strdup(constant_name_maps(maps, val)); 171 } 172 173 /* Pretty-print a field from BUF as described by F. */ 174 void 175 field_dump_field(struct field *f, u_int8_t *buf) 176 { 177 char *value; 178 179 value = decode_field[(int) f->type] (buf + f->offset, f->len, f->maps); 180 if (value) { 181 LOG_DBG((LOG_MESSAGE, 70, "%s: %s", f->name, value)); 182 free(value); 183 } 184 } 185 186 /* Pretty-print all the fields of BUF as described in FIELDS. */ 187 void 188 field_dump_payload(struct field *fields, u_int8_t *buf) 189 { 190 struct field *field; 191 192 for (field = fields; field->name; field++) 193 field_dump_field(field, buf); 194 } 195 196 /* Return the numeric value of the field F of BUF. */ 197 u_int32_t 198 field_get_num(struct field *f, u_int8_t *buf) 199 { 200 u_int32_t val; 201 202 if (extract_val(buf + f->offset, f->len, &val)) 203 return 0; 204 return val; 205 } 206 207 /* Stash the number VAL into BUF's field F. */ 208 void 209 field_set_num(struct field *f, u_int8_t *buf, u_int32_t val) 210 { 211 switch (f->len) { 212 case 1: 213 buf[f->offset] = val; 214 break; 215 case 2: 216 encode_16(buf + f->offset, val); 217 break; 218 case 4: 219 encode_32(buf + f->offset, val); 220 break; 221 } 222 } 223 224 /* Stash BUF's raw field F into VAL. */ 225 void 226 field_get_raw(struct field *f, u_int8_t *buf, u_int8_t *val) 227 { 228 memcpy(val, buf + f->offset, f->len); 229 } 230 231 /* Stash the buffer VAL into BUF's field F. */ 232 void 233 field_set_raw(struct field *f, u_int8_t *buf, u_int8_t *val) 234 { 235 memcpy(buf + f->offset, val, f->len); 236 } 237