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 */ 29 30 #define ACCEPT_FILTER_MOD 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/sysproto.h> 35 #include <sys/kernel.h> 36 #include <sys/proc.h> 37 #include <sys/malloc.h> 38 #include <sys/unistd.h> 39 #include <sys/file.h> 40 #include <sys/fcntl.h> 41 #include <sys/protosw.h> 42 #include <sys/sysctl.h> 43 #include <sys/socket.h> 44 #include <sys/socketvar.h> 45 #include <sys/stat.h> 46 #include <sys/mbuf.h> 47 #include <sys/resource.h> 48 #include <sys/sysent.h> 49 #include <sys/resourcevar.h> 50 51 /* check for GET/HEAD */ 52 static void sohashttpget(struct socket *so, void *arg, int waitflag); 53 /* check for HTTP/1.0 or HTTP/1.1 */ 54 static void soparsehttpvers(struct socket *so, void *arg, int waitflag); 55 /* check for end of HTTP/1.x request */ 56 static void soishttpconnected(struct socket *so, void *arg, int waitflag); 57 /* strcmp on an mbuf chain */ 58 static int mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, char *cmp); 59 /* strncmp on an mbuf chain */ 60 static int mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset, 61 int max, char *cmp); 62 /* socketbuffer is full */ 63 static int sbfull(struct sockbuf *sb); 64 65 static struct accept_filter accf_http_filter = { 66 "httpready", 67 sohashttpget, 68 NULL, 69 NULL 70 }; 71 72 static moduledata_t accf_http_mod = { 73 "accf_http", 74 accept_filt_generic_mod_event, 75 &accf_http_filter 76 }; 77 78 DECLARE_MODULE(accf_http, accf_http_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE); 79 80 static int parse_http_version = 1; 81 82 SYSCTL_NODE(_net_inet_accf, OID_AUTO, http, CTLFLAG_RW, 0, 83 "HTTP accept filter"); 84 SYSCTL_INT(_net_inet_accf_http, OID_AUTO, parsehttpversion, CTLFLAG_RW, 85 &parse_http_version, 1, 86 "Parse http version so that non 1.x requests work"); 87 88 #ifdef ACCF_HTTP_DEBUG 89 #define DPRINT(fmt, args...) \ 90 do { \ 91 printf("%s:%d: " fmt "\n", __func__, __LINE__ , ##args); \ 92 } while (0) 93 #else 94 #define DPRINT(fmt, args...) 95 #endif 96 97 static int 98 sbfull(struct sockbuf *sb) 99 { 100 101 DPRINT("sbfull, cc(%ld) >= hiwat(%ld): %d, mbcnt(%ld) >= mbmax(%ld): %d", 102 sb->sb_cc, sb->sb_hiwat, sb->sb_cc >= sb->sb_hiwat, 103 sb->sb_mbcnt, sb->sb_mbmax, sb->sb_mbcnt >= sb->sb_mbmax); 104 return(sb->sb_cc >= sb->sb_hiwat || sb->sb_mbcnt >= sb->sb_mbmax); 105 } 106 107 /* 108 * start at mbuf m, (must provide npkt if exists) 109 * starting at offset in m compare characters in mbuf chain for 'cmp' 110 */ 111 static int 112 mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, char *cmp) 113 { 114 struct mbuf *n; 115 116 for (;m != NULL; m = n) { 117 n = npkt; 118 if (npkt) 119 npkt = npkt->m_nextpkt; 120 for (; m; m = m->m_next) { 121 for (; offset < m->m_len; offset++, cmp++) { 122 if (*cmp == '\0') { 123 return (1); 124 } else if (*cmp != *(mtod(m, char *) + offset)) { 125 return (0); 126 } 127 } 128 if (*cmp == '\0') 129 return (1); 130 offset = 0; 131 } 132 } 133 return (0); 134 } 135 136 /* 137 * start at mbuf m, (must provide npkt if exists) 138 * starting at offset in m compare characters in mbuf chain for 'cmp' 139 * stop at 'max' characters 140 */ 141 static int 142 mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset, int max, char *cmp) 143 { 144 struct mbuf *n; 145 146 for (;m != NULL; m = n) { 147 n = npkt; 148 if (npkt) 149 npkt = npkt->m_nextpkt; 150 for (; m; m = m->m_next) { 151 for (; offset < m->m_len; offset++, cmp++, max--) { 152 if (max == 0 || *cmp == '\0') { 153 return (1); 154 } else if (*cmp != *(mtod(m, char *) + offset)) { 155 return (0); 156 } 157 } 158 if (max == 0 || *cmp == '\0') 159 return (1); 160 offset = 0; 161 } 162 } 163 return (0); 164 } 165 166 #define STRSETUP(sptr, slen, str) \ 167 do { \ 168 sptr = str; \ 169 slen = sizeof(str) - 1; \ 170 } while(0) 171 172 static void 173 sohashttpget(struct socket *so, void *arg, int waitflag) 174 { 175 176 if ((so->so_state & SS_CANTRCVMORE) == 0 && !sbfull(&so->so_rcv)) { 177 struct mbuf *m; 178 char *cmp; 179 int cmplen, cc; 180 181 m = so->so_rcv.sb_mb; 182 cc = so->so_rcv.sb_cc - 1; 183 if (cc < 1) 184 return; 185 switch (*mtod(m, char *)) { 186 case 'G': 187 STRSETUP(cmp, cmplen, "ET "); 188 break; 189 case 'H': 190 STRSETUP(cmp, cmplen, "EAD "); 191 break; 192 default: 193 goto fallout; 194 } 195 if (cc < cmplen) { 196 if (mbufstrncmp(m, m->m_nextpkt, 1, cc, cmp) == 1) { 197 DPRINT("short cc (%d) but mbufstrncmp ok", cc); 198 return; 199 } else { 200 DPRINT("short cc (%d) mbufstrncmp failed", cc); 201 goto fallout; 202 } 203 } 204 if (mbufstrcmp(m, m->m_nextpkt, 1, cmp) == 1) { 205 DPRINT("mbufstrcmp ok"); 206 if (parse_http_version == 0) 207 soishttpconnected(so, arg, waitflag); 208 else 209 soparsehttpvers(so, arg, waitflag); 210 return; 211 } 212 DPRINT("mbufstrcmp bad"); 213 } 214 215 fallout: 216 DPRINT("fallout"); 217 so->so_upcall = NULL; 218 so->so_rcv.sb_flags &= ~SB_UPCALL; 219 soisconnected(so); 220 return; 221 } 222 223 static void 224 soparsehttpvers(struct socket *so, void *arg, int waitflag) 225 { 226 struct mbuf *m, *n; 227 int i, cc, spaces, inspaces; 228 229 if ((so->so_state & SS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv)) 230 goto fallout; 231 232 m = so->so_rcv.sb_mb; 233 cc = so->so_rcv.sb_cc; 234 inspaces = spaces = 0; 235 for (m = so->so_rcv.sb_mb; m; m = n) { 236 n = m->m_nextpkt; 237 for (; m; m = m->m_next) { 238 for (i = 0; i < m->m_len; i++, cc--) { 239 switch (*(mtod(m, char *) + i)) { 240 case ' ': 241 if (!inspaces) { 242 spaces++; 243 inspaces = 1; 244 } 245 break; 246 case '\r': 247 case '\n': 248 DPRINT("newline"); 249 goto fallout; 250 default: 251 if (spaces == 2) { 252 /* make sure we have enough data left */ 253 if (cc < sizeof("HTTP/1.0") - 1) { 254 if (mbufstrncmp(m, n, i, cc, "HTTP/1.") == 1) { 255 DPRINT("mbufstrncmp ok"); 256 goto readmore; 257 } else { 258 DPRINT("mbufstrncmp bad"); 259 goto fallout; 260 } 261 } else if (mbufstrcmp(m, n, i, "HTTP/1.0") == 1 || 262 mbufstrcmp(m, n, i, "HTTP/1.1") == 1) { 263 DPRINT("mbufstrcmp ok"); 264 soishttpconnected(so, arg, waitflag); 265 return; 266 } else { 267 DPRINT("mbufstrcmp bad"); 268 goto fallout; 269 } 270 } 271 inspaces = 0; 272 break; 273 } 274 } 275 } 276 } 277 readmore: 278 DPRINT("readmore"); 279 /* 280 * if we hit here we haven't hit something 281 * we don't understand or a newline, so try again 282 */ 283 so->so_upcall = soparsehttpvers; 284 so->so_rcv.sb_flags |= SB_UPCALL; 285 return; 286 287 fallout: 288 DPRINT("fallout"); 289 so->so_upcall = NULL; 290 so->so_rcv.sb_flags &= ~SB_UPCALL; 291 soisconnected(so); 292 return; 293 } 294 295 296 #define NCHRS 3 297 298 static void 299 soishttpconnected(struct socket *so, void *arg, int waitflag) 300 { 301 char a, b, c; 302 struct mbuf *m, *n; 303 int ccleft, copied; 304 305 DPRINT("start"); 306 if ((so->so_state & SS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv)) 307 goto gotit; 308 309 /* 310 * Walk the socketbuffer and copy the last NCHRS (3) into a, b, and c 311 * copied - how much we've copied so far 312 * ccleft - how many bytes remaining in the socketbuffer 313 * just loop over the mbufs subtracting from 'ccleft' until we only 314 * have NCHRS left 315 */ 316 copied = 0; 317 ccleft = so->so_rcv.sb_cc; 318 if (ccleft < NCHRS) 319 goto readmore; 320 a = b = c = '\0'; 321 for (m = so->so_rcv.sb_mb; m; m = n) { 322 n = m->m_nextpkt; 323 for (; m; m = m->m_next) { 324 ccleft -= m->m_len; 325 if (ccleft <= NCHRS) { 326 char *src; 327 int tocopy; 328 329 tocopy = (NCHRS - ccleft) - copied; 330 src = mtod(m, char *) + (m->m_len - tocopy); 331 332 while (tocopy--) { 333 switch (copied++) { 334 case 0: 335 a = *src++; 336 break; 337 case 1: 338 b = *src++; 339 break; 340 case 2: 341 c = *src++; 342 break; 343 } 344 } 345 } 346 } 347 } 348 if (c == '\n' && (b == '\n' || (b == '\r' && a == '\n'))) { 349 /* we have all request headers */ 350 goto gotit; 351 } 352 353 readmore: 354 so->so_upcall = soishttpconnected; 355 so->so_rcv.sb_flags |= SB_UPCALL; 356 return; 357 358 gotit: 359 so->so_upcall = NULL; 360 so->so_rcv.sb_flags &= ~SB_UPCALL; 361 soisconnected(so); 362 return; 363 } 364