1/* @(#) parsing functions for udpxy 2 * 3 * Copyright 2008-2011 Pavel V. Cherenkov (pcherenkov@gmail.com) 4 * 5 * This file is part of udpxy. 6 * 7 * udpxy is free software: you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation, either version 3 of the License, or 10 * (at your option) any later version. 11 * 12 * udpxy is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with udpxy. If not, see <http://www.gnu.org/licenses/>. 19 */ 20 21#include <string.h> 22#include <sys/types.h> 23#include <stdlib.h> 24#include <stdio.h> 25#include <errno.h> 26 27#include <sys/socket.h> 28#include <netinet/in.h> 29#include <arpa/inet.h> 30 31#include <assert.h> 32 33#include "rparse.h" 34#include "mtrace.h" 35 36/* parse and copy parameters of HTTP GET request into 37 * request buffer 38 * 39 * @param src buffer with raw source data 40 * @param srclen length of raw data 41 * @param request destination buffer for the request 42 * @param rqlen length of request buffer on entry 43 * length of request on exit 44 * 45 * @return 0 if success: request buffer gets populated, 46 * non-zero if error 47 */ 48int 49get_request( const char* src, size_t srclen, 50 char* request, size_t* rqlen ) 51{ 52 const char HEAD[] = "GET /"; 53 char* p = NULL; 54 const char* EOD = src + srclen - 1; 55 size_t n = 0; 56 const char SPACE[] = " "; 57 58 p = strstr( src, HEAD ); 59 if( NULL == p ) return 1; /* no header */ 60 61 p += (sizeof(HEAD) - 1); 62 if( p >= EOD) /* no request */ 63 return 2; 64 65 n = strcspn( p, " " ); 66 if( (SPACE[0] != p[n]) || ((p + n) > EOD) || (n >= *rqlen) ) /* overflow */ 67 return 3; 68 69 (void) strncpy( request, p, n ); 70 request[ n ] = '\0'; 71 72 *rqlen = n; 73 74 return 0; 75} 76 77 78/* parse (GET) request into command and parameters (options) 79 * c-strings 80 * 81 * @param s source c-string 82 * @param cmd buffer for the parsed command c-string 83 * @param clen length of command buffer 84 * @param opt buffer for the parsed options c-string 85 * @param optlen length of options buffer 86 * @param tail buffer for tail (whatever is beyond options) 87 * @param tlen length of tail buffer 88 * 89 * @return 0 if success: cmd and opt get get populated 90 * non-zero if an error ocurred 91 */ 92int 93parse_param( const char* s, size_t slen, 94 char* cmd, size_t clen, 95 char* opt, size_t optlen, 96 char* tail, size_t tlen) 97{ 98 const char DLM = '/'; 99 size_t i, j, n = 0; 100 101 assert( s && cmd && (clen > (size_t)0) && opt && (optlen > (size_t)0) ); 102 103 *cmd = *opt = '\0'; 104 if( (size_t)0 == slen ) return 0; /* empty source */ 105 106 /* request ::= [DLM] cmd [DLM opt] */ 107 108 /* skip leading delimiter */ 109 i = ( DLM == s[0] ) ? 1 : 0; 110 111 /* copy into cmd until next delimiter or EOD */ 112 for( j = 0; (i < slen) && (j < clen) && s[i] && (s[i] != DLM); ) { 113 cmd[j++] = s[i++]; 114 } 115 if( j >= clen ) return EOVERFLOW; 116 cmd[ j ] = '\0'; 117 118 /* skip dividing delimiter */ 119 if( DLM == s[i] ) 120 ++i; 121 122 /* over the edge yet? */ 123 if (i >= slen) 124 return 0; 125 126 /* look for '?' separating options from tail */ 127 n = strcspn(s + i, "?"); 128 if (n < optlen) { 129 (void) strncpy( opt, s + i, n ); 130 opt[n] = '\0'; 131 } 132 else 133 return EOVERFLOW; 134 135 i += n; 136 if (i >= slen) return 0; 137 138 if (tail && tlen > 0) { 139 (void) strncpy(tail, s + i, tlen); 140 tail[tlen - 1] = '\0'; 141 } 142 143 return 0; 144} 145 146 147 148/* parse options of upd-relay command into IP address 149 * and port 150 * 151 * @param opt options string 152 * @param addr destination for address string 153 * @param addrlen length of address string buffer 154 * @param port port to populate 155 * 156 * @return 0 if success: inaddr and port get populated 157 * non-zero if error 158 */ 159int 160parse_udprelay( const char* opt, size_t optlen, 161 char* addr, size_t addrlen, 162 uint16_t* port ) 163{ 164 int rc = 1; 165 size_t n; 166 int pval; 167 168 const char* SEP = ":%~+-^"; 169 const int MAX_PORT = 65535; 170 171 #define MAX_OPTLEN 512 172 char s[ MAX_OPTLEN ]; 173 174 assert( opt && addr && addrlen && port ); 175 176 (void) strncpy( s, opt, MAX_OPTLEN ); 177 s[ MAX_OPTLEN - 1 ] = '\0'; 178 do { 179 n = strcspn( s, SEP ); 180 if( !n || n >= optlen ) break; 181 s[n] = '\0'; 182 183 strncpy( addr, s, addrlen ); 184 addr[ addrlen - 1 ] ='\0'; 185 186 ++n; 187 pval = atoi( s + n ); 188 if( (pval > 0) && (pval < MAX_PORT) ) { 189 *port = (uint16_t)pval; 190 } 191 else { 192 rc = 3; 193 break; 194 } 195 196 rc = 0; 197 } 198 while(0); 199 200 return rc; 201} 202 203/* __EOF__ */ 204 205