/* $NetBSD: accf_http.c,v 1.7 2009/09/02 14:56:57 tls Exp $ */ /*- * Copyright (c) 2000 Paycounter, Inc. * Author: Alfred Perlstein , * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __KERNEL_RCSID(0, "$NetBSD: accf_http.c,v 1.7 2009/09/02 14:56:57 tls Exp $"); #define ACCEPT_FILTER_MOD #include #include #include #include #include #include #include #include #include MODULE(MODULE_CLASS_MISC, accf_httpready, NULL); /* check for GET/HEAD */ static void sohashttpget(struct socket *so, void *arg, int events, int waitflag); /* check for HTTP/1.0 or HTTP/1.1 */ static void soparsehttpvers(struct socket *so, void *arg, int events, int waitflag); /* check for end of HTTP/1.x request */ static void soishttpconnected(struct socket *so, void *arg, int events, int waitflag); /* strcmp on an mbuf chain */ static int mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, const char *cmp); /* strncmp on an mbuf chain */ static int mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset, int len, const char *cmp); /* socketbuffer is full */ static int sbfull(struct sockbuf *sb); static struct accept_filter accf_http_filter = { .accf_name = "httpready", .accf_callback = sohashttpget, }; /* * Names of HTTP Accept filter sysctl objects */ #define ACCFCTL_PARSEVER 1 /* Parse HTTP version */ static int parse_http_version = 1; /* XXX pseudo-device */ void accf_httpattach(int); void accf_httpattach(int junk) { } static int accf_httpready_modcmd(modcmd_t cmd, void *arg) { static struct sysctllog *clog; int error; switch (cmd) { case MODULE_CMD_INIT: error = accept_filt_add(&accf_http_filter); if (error != 0) { return error; } sysctl_createv(&clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "net", NULL, NULL, 0, NULL, 0, CTL_NET, CTL_EOL); sysctl_createv(&clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "inet", NULL, NULL, 0, NULL, 0, CTL_NET, PF_INET, CTL_EOL); sysctl_createv(&clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "accf", NULL, NULL, 0, NULL, 0, CTL_NET, PF_INET, SO_ACCEPTFILTER, CTL_EOL); sysctl_createv(&clog, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "http", SYSCTL_DESCR("HTTP accept filter"), NULL, 0, NULL, 0, CTL_NET, PF_INET, SO_ACCEPTFILTER, ACCF_HTTP, CTL_EOL); sysctl_createv(&clog, 0, NULL, NULL, CTLFLAG_PERMANENT|CTLFLAG_READWRITE, CTLTYPE_INT, "parsehttpversion", SYSCTL_DESCR("Parse http version so that non " "1.x requests work"), NULL, 0, &parse_http_version, 0, CTL_NET, PF_INET, SO_ACCEPTFILTER, ACCF_HTTP, ACCFCTL_PARSEVER, CTL_EOL); return 0; case MODULE_CMD_FINI: error = accept_filt_del(&accf_http_filter); if (error != 0) { return error; } sysctl_teardown(&clog); return 0; default: return ENOTTY; } } #ifdef ACCF_HTTP_DEBUG #define DPRINT(fmt, args...) \ do { \ printf("%s:%d: " fmt "\n", __func__, __LINE__, ##args); \ } while (0) #else #define DPRINT(fmt, args...) #endif static int sbfull(struct sockbuf *sb) { DPRINT("sbfull, cc(%ld) >= hiwat(%ld): %d, " "mbcnt(%ld) >= mbmax(%ld): %d", sb->sb_cc, sb->sb_hiwat, sb->sb_cc >= sb->sb_hiwat, sb->sb_mbcnt, sb->sb_mbmax, sb->sb_mbcnt >= sb->sb_mbmax); return (sb->sb_cc >= sb->sb_hiwat || sb->sb_mbcnt >= sb->sb_mbmax); } /* * start at mbuf m, (must provide npkt if exists) * starting at offset in m compare characters in mbuf chain for 'cmp' */ static int mbufstrcmp(struct mbuf *m, struct mbuf *npkt, int offset, const char *cmp) { struct mbuf *n; for (; m != NULL; m = n) { n = npkt; if (npkt) npkt = npkt->m_nextpkt; for (; m; m = m->m_next) { for (; offset < m->m_len; offset++, cmp++) { if (*cmp == '\0') return (1); else if (*cmp != *(mtod(m, char *) + offset)) return (0); } if (*cmp == '\0') return (1); offset = 0; } } return (0); } /* * start at mbuf m, (must provide npkt if exists) * starting at offset in m compare characters in mbuf chain for 'cmp' * stop at 'max' characters */ static int mbufstrncmp(struct mbuf *m, struct mbuf *npkt, int offset, int len, const char *cmp) { struct mbuf *n; for (; m != NULL; m = n) { n = npkt; if (npkt) npkt = npkt->m_nextpkt; for (; m; m = m->m_next) { for (; offset < m->m_len; offset++, cmp++, len--) { if (len == 0 || *cmp == '\0') return (1); else if (*cmp != *(mtod(m, char *) + offset)) return (0); } if (len == 0 || *cmp == '\0') return (1); offset = 0; } } return (0); } #define STRSETUP(sptr, slen, str) \ do { \ sptr = str; \ slen = sizeof(str) - 1; \ } while(0) static void sohashttpget(struct socket *so, void *arg, int events, int waitflag) { if ((so->so_state & SS_CANTRCVMORE) == 0 && !sbfull(&so->so_rcv)) { struct mbuf *m; const char *cmp; int cmplen, cc; m = so->so_rcv.sb_mb; cc = so->so_rcv.sb_cc - 1; if (cc < 1) return; switch (*mtod(m, char *)) { case 'G': STRSETUP(cmp, cmplen, "ET "); break; case 'H': STRSETUP(cmp, cmplen, "EAD "); break; default: goto fallout; } if (cc < cmplen) { if (mbufstrncmp(m, m->m_nextpkt, 1, cc, cmp) == 1) { DPRINT("short cc (%d) but mbufstrncmp ok", cc); return; } else { DPRINT("short cc (%d) mbufstrncmp failed", cc); goto fallout; } } if (mbufstrcmp(m, m->m_nextpkt, 1, cmp) == 1) { DPRINT("mbufstrcmp ok"); if (parse_http_version == 0) soishttpconnected(so, arg, events, waitflag); else soparsehttpvers(so, arg, events, waitflag); return; } DPRINT("mbufstrcmp bad"); } fallout: DPRINT("fallout"); so->so_upcall = NULL; so->so_rcv.sb_flags &= ~SB_UPCALL; soisconnected(so); return; } static void soparsehttpvers(struct socket *so, void *arg, int events, int waitflag) { struct mbuf *m, *n; int i, cc, spaces, inspaces; if ((so->so_state & SS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv)) goto fallout; m = so->so_rcv.sb_mb; cc = so->so_rcv.sb_cc; inspaces = spaces = 0; for (m = so->so_rcv.sb_mb; m; m = n) { n = m->m_nextpkt; for (; m; m = m->m_next) { for (i = 0; i < m->m_len; i++, cc--) { switch (*(mtod(m, char *) + i)) { case ' ': /* tabs? '\t' */ if (!inspaces) { spaces++; inspaces = 1; } break; case '\r': case '\n': DPRINT("newline"); goto fallout; default: if (spaces != 2) { inspaces = 0; break; } /* * if we don't have enough characters * left (cc < sizeof("HTTP/1.0") - 1) * then see if the remaining ones * are a request we can parse. */ if (cc < sizeof("HTTP/1.0") - 1) { if (mbufstrncmp(m, n, i, cc, "HTTP/1.") == 1) { DPRINT("ok"); goto readmore; } else { DPRINT("bad"); goto fallout; } } else if ( mbufstrcmp(m, n, i, "HTTP/1.0") || mbufstrcmp(m, n, i, "HTTP/1.1")) { DPRINT("ok"); soishttpconnected(so, arg, events, waitflag); return; } else { DPRINT("bad"); goto fallout; } } } } } readmore: DPRINT("readmore"); /* * if we hit here we haven't hit something * we don't understand or a newline, so try again */ so->so_upcall = soparsehttpvers; so->so_rcv.sb_flags |= SB_UPCALL; return; fallout: DPRINT("fallout"); so->so_upcall = NULL; so->so_rcv.sb_flags &= ~SB_UPCALL; soisconnected(so); return; } #define NCHRS 3 static void soishttpconnected(struct socket *so, void *arg, int events, int waitflag) { char a, b, c; struct mbuf *m, *n; int ccleft, copied; DPRINT("start"); if ((so->so_state & SS_CANTRCVMORE) != 0 || sbfull(&so->so_rcv)) goto gotit; /* * Walk the socketbuffer and copy the last NCHRS (3) into a, b, and c * copied - how much we've copied so far * ccleft - how many bytes remaining in the socketbuffer * just loop over the mbufs subtracting from 'ccleft' until we only * have NCHRS left */ copied = 0; ccleft = so->so_rcv.sb_cc; if (ccleft < NCHRS) goto readmore; a = b = c = '\0'; for (m = so->so_rcv.sb_mb; m; m = n) { n = m->m_nextpkt; for (; m; m = m->m_next) { ccleft -= m->m_len; if (ccleft <= NCHRS) { char *src; int tocopy; tocopy = (NCHRS - ccleft) - copied; src = mtod(m, char *) + (m->m_len - tocopy); while (tocopy--) { switch (copied++) { case 0: a = *src++; break; case 1: b = *src++; break; case 2: c = *src++; break; } } } } } if (c == '\n' && (b == '\n' || (b == '\r' && a == '\n'))) { /* we have all request headers */ goto gotit; } readmore: so->so_upcall = soishttpconnected; so->so_rcv.sb_flags |= SB_UPCALL; return; gotit: so->so_upcall = NULL; so->so_rcv.sb_flags &= ~SB_UPCALL; soisconnected(so); return; }