1 /* 2 * Copyright (c) 2000 Paycounter, Inc. 3 * Author: Alfred Perlstein <alfred@paycounter.com>, <alfred@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 * $FreeBSD: src/sys/netinet/accf_http.c,v 1.1.2.4 2002/05/01 08:34:37 alfred Exp $ 28 * $DragonFly: src/sys/net/accf_http/accf_http.c,v 1.2 2003/06/17 04:28:51 dillon Exp $ 29 */ 30 31 #define ACCEPT_FILTER_MOD 32 33 #include <sys/param.h> 34 #include <sys/systm.h> 35 #include <sys/sysproto.h> 36 #include <sys/kernel.h> 37 #include <sys/proc.h> 38 #include <sys/malloc.h> 39 #include <sys/unistd.h> 40 #include <sys/file.h> 41 #include <sys/fcntl.h> 42 #include <sys/protosw.h> 43 #include <sys/sysctl.h> 44 #include <sys/socket.h> 45 #include <sys/socketvar.h> 46 #include <sys/stat.h> 47 #include <sys/mbuf.h> 48 #include <sys/resource.h> 49 #include <sys/sysent.h> 50 #include <sys/resourcevar.h> 51 52 /* check for GET/HEAD */ 53 static void sohashttpget(struct socket *so, void *arg, int waitflag); 54 /* check for HTTP/1.0 or HTTP/1.1 */ 55 static void soparsehttpvers(struct socket *so, void *arg, int waitflag); 56 /* check for end of HTTP/1.x request */ 57 static void soishttpconnected(struct socket *so, void *arg, int waitflag); 58 /* strcmp on an mbuf chain */ 59 static int mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, char *cmp); 60 /* strncmp on an mbuf chain */ 61 static int mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset, 62 int max, char *cmp); 63 /* socketbuffer is full */ 64 static int sbfull(struct sockbuf *sb); 65 66 static struct accept_filter accf_http_filter = { 67 "httpready", 68 sohashttpget, 69 NULL, 70 NULL 71 }; 72 73 static moduledata_t accf_http_mod = { 74 "accf_http", 75 accept_filt_generic_mod_event, 76 &accf_http_filter 77 }; 78 79 DECLARE_MODULE(accf_http, accf_http_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE); 80 81 static int parse_http_version = 1; 82 83 SYSCTL_NODE(_net_inet_accf, OID_AUTO, http, CTLFLAG_RW, 0, 84 "HTTP accept filter"); 85 SYSCTL_INT(_net_inet_accf_http, OID_AUTO, parsehttpversion, CTLFLAG_RW, 86 &parse_http_version, 1, 87 "Parse http version so that non 1.x requests work"); 88 89 #ifdef ACCF_HTTP_DEBUG 90 #define DPRINT(fmt, args...) \ 91 do { \ 92 printf("%s:%d: " fmt "\n", __func__, __LINE__ , ##args); \ 93 } while (0) 94 #else 95 #define DPRINT(fmt, args...) 96 #endif 97 98 static int 99 sbfull(struct sockbuf *sb) 100 { 101 102 DPRINT("sbfull, cc(%ld) >= hiwat(%ld): %d, mbcnt(%ld) >= mbmax(%ld): %d", 103 sb->sb_cc, sb->sb_hiwat, sb->sb_cc >= sb->sb_hiwat, 104 sb->sb_mbcnt, sb->sb_mbmax, sb->sb_mbcnt >= sb->sb_mbmax); 105 return(sb->sb_cc >= sb->sb_hiwat || sb->sb_mbcnt >= sb->sb_mbmax); 106 } 107 108 /* 109 * start at mbuf m, (must provide npkt if exists) 110 * starting at offset in m compare characters in mbuf chain for 'cmp' 111 */ 112 static int 113 mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, char *cmp) 114 { 115 struct mbuf *n; 116 117 for (;m != NULL; m = n) { 118 n = npkt; 119 if (npkt) 120 npkt = npkt->m_nextpkt; 121 for (; m; m = m->m_next) { 122 for (; offset < m->m_len; offset++, cmp++) { 123 if (*cmp == '\0') { 124 return (1); 125 } else if (*cmp != *(mtod(m, char *) + offset)) { 126 return (0); 127 } 128 } 129 if (*cmp == '\0') 130 return (1); 131 offset = 0; 132 } 133 } 134 return (0); 135 } 136 137 /* 138 * start at mbuf m, (must provide npkt if exists) 139 * starting at offset in m compare characters in mbuf chain for 'cmp' 140 * stop at 'max' characters 141 */ 142 static int 143 mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset, int max, char *cmp) 144 { 145 struct mbuf *n; 146 147 for (;m != NULL; m = n) { 148 n = npkt; 149 if (npkt) 150 npkt = npkt->m_nextpkt; 151 for (; m; m = m->m_next) { 152 for (; offset < m->m_len; offset++, cmp++, max--) { 153 if (max == 0 || *cmp == '\0') { 154 return (1); 155 } else if (*cmp != *(mtod(m, char *) + offset)) { 156 return (0); 157 } 158 } 159 if (max == 0 || *cmp == '\0') 160 return (1); 161 offset = 0; 162 } 163 } 164 return (0); 165 } 166 167 #define STRSETUP(sptr, slen, str) \ 168 do { \ 169 sptr = str; \ 170 slen = sizeof(str) - 1; \ 171 } while(0) 172 173 static void 174 sohashttpget(struct socket *so, void *arg, int waitflag) 175 { 176 177 if ((so->so_state & SS_CANTRCVMORE) == 0 && !sbfull(&so->so_rcv)) { 178 struct mbuf *m; 179 char *cmp; 180 int cmplen, cc; 181 182 m = so->so_rcv.sb_mb; 183 cc = so->so_rcv.sb_cc - 1; 184 if (cc < 1) 185 return; 186 switch (*mtod(m, char *)) { 187 case 'G': 188 STRSETUP(cmp, cmplen, "ET "); 189 break; 190 case 'H': 191 STRSETUP(cmp, cmplen, "EAD "); 192 break; 193 default: 194 goto fallout; 195 } 196 if (cc < cmplen) { 197 if (mbufstrncmp(m, m->m_nextpkt, 1, cc, cmp) == 1) { 198 DPRINT("short cc (%d) but mbufstrncmp ok", cc); 199 return; 200 } else { 201 DPRINT("short cc (%d) mbufstrncmp failed", cc); 202 goto fallout; 203 } 204 } 205 if (mbufstrcmp(m, m->m_nextpkt, 1, cmp) == 1) { 206 DPRINT("mbufstrcmp ok"); 207 if (parse_http_version == 0) 208 soishttpconnected(so, arg, waitflag); 209 else 210 soparsehttpvers(so, arg, waitflag); 211 return; 212 } 213 DPRINT("mbufstrcmp bad"); 214 } 215 216 fallout: 217 DPRINT("fallout"); 218 so->so_upcall = NULL; 219 so->so_rcv.sb_flags &= ~SB_UPCALL; 220 soisconnected(so); 221 return; 222 } 223 224 static void 225 soparsehttpvers(struct socket *so, void *arg, int waitflag) 226 { 227 struct mbuf *m, *n; 228 int i, cc, spaces, inspaces; 229 230 if ((so->so_state & SS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv)) 231 goto fallout; 232 233 m = so->so_rcv.sb_mb; 234 cc = so->so_rcv.sb_cc; 235 inspaces = spaces = 0; 236 for (m = so->so_rcv.sb_mb; m; m = n) { 237 n = m->m_nextpkt; 238 for (; m; m = m->m_next) { 239 for (i = 0; i < m->m_len; i++, cc--) { 240 switch (*(mtod(m, char *) + i)) { 241 case ' ': 242 if (!inspaces) { 243 spaces++; 244 inspaces = 1; 245 } 246 break; 247 case '\r': 248 case '\n': 249 DPRINT("newline"); 250 goto fallout; 251 default: 252 if (spaces == 2) { 253 /* make sure we have enough data left */ 254 if (cc < sizeof("HTTP/1.0") - 1) { 255 if (mbufstrncmp(m, n, i, cc, "HTTP/1.") == 1) { 256 DPRINT("mbufstrncmp ok"); 257 goto readmore; 258 } else { 259 DPRINT("mbufstrncmp bad"); 260 goto fallout; 261 } 262 } else if (mbufstrcmp(m, n, i, "HTTP/1.0") == 1 || 263 mbufstrcmp(m, n, i, "HTTP/1.1") == 1) { 264 DPRINT("mbufstrcmp ok"); 265 soishttpconnected(so, arg, waitflag); 266 return; 267 } else { 268 DPRINT("mbufstrcmp bad"); 269 goto fallout; 270 } 271 } 272 inspaces = 0; 273 break; 274 } 275 } 276 } 277 } 278 readmore: 279 DPRINT("readmore"); 280 /* 281 * if we hit here we haven't hit something 282 * we don't understand or a newline, so try again 283 */ 284 so->so_upcall = soparsehttpvers; 285 so->so_rcv.sb_flags |= SB_UPCALL; 286 return; 287 288 fallout: 289 DPRINT("fallout"); 290 so->so_upcall = NULL; 291 so->so_rcv.sb_flags &= ~SB_UPCALL; 292 soisconnected(so); 293 return; 294 } 295 296 297 #define NCHRS 3 298 299 static void 300 soishttpconnected(struct socket *so, void *arg, int waitflag) 301 { 302 char a, b, c; 303 struct mbuf *m, *n; 304 int ccleft, copied; 305 306 DPRINT("start"); 307 if ((so->so_state & SS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv)) 308 goto gotit; 309 310 /* 311 * Walk the socketbuffer and copy the last NCHRS (3) into a, b, and c 312 * copied - how much we've copied so far 313 * ccleft - how many bytes remaining in the socketbuffer 314 * just loop over the mbufs subtracting from 'ccleft' until we only 315 * have NCHRS left 316 */ 317 copied = 0; 318 ccleft = so->so_rcv.sb_cc; 319 if (ccleft < NCHRS) 320 goto readmore; 321 a = b = c = '\0'; 322 for (m = so->so_rcv.sb_mb; m; m = n) { 323 n = m->m_nextpkt; 324 for (; m; m = m->m_next) { 325 ccleft -= m->m_len; 326 if (ccleft <= NCHRS) { 327 char *src; 328 int tocopy; 329 330 tocopy = (NCHRS - ccleft) - copied; 331 src = mtod(m, char *) + (m->m_len - tocopy); 332 333 while (tocopy--) { 334 switch (copied++) { 335 case 0: 336 a = *src++; 337 break; 338 case 1: 339 b = *src++; 340 break; 341 case 2: 342 c = *src++; 343 break; 344 } 345 } 346 } 347 } 348 } 349 if (c == '\n' && (b == '\n' || (b == '\r' && a == '\n'))) { 350 /* we have all request headers */ 351 goto gotit; 352 } 353 354 readmore: 355 so->so_upcall = soishttpconnected; 356 so->so_rcv.sb_flags |= SB_UPCALL; 357 return; 358 359 gotit: 360 so->so_upcall = NULL; 361 so->so_rcv.sb_flags &= ~SB_UPCALL; 362 soisconnected(so); 363 return; 364 } 365