📄 filters.c
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char *filters_rcs = "$Id: filters.c,v 1.15 1998/10/23 01:54:03 ACJC Exp $";/* Written and copyright 1997 Anonymous Coders and Junkbusters Corporation. * Distributed under the GNU General Public License; see the README file. * This code comes with NO WARRANTY. http://www.junkbusters.com/ht/en/gpl.html */#include <stdio.h>#include <sys/types.h>#include <stdlib.h>#include <ctype.h>#include <string.h>#ifndef _WIN32#include <unistd.h>#endif#ifdef REGEX#include <gnu_regex.h>#endif#include "jcc.h"#define URL(X) url_encode(url_code_map, (X))char CBLOCK[] = "HTTP/1.0 202 Request for blocked URL\n" "Pragma: no-cache\n" "Last-Modified: Thu Jul 31, 1997 07:42:22 pm GMT\n" "Expires: Thu Jul 31, 1997 07:42:22 pm GMT\n" "Content-Type: text/html\n\n" "<html>\n" "<head>\n" "<title>Internet Junkbuster: Request for blocked URL</title>\n" "</head>\n" WHITEBG "<center>" "<a href=http://internet.junkbuster.com/ij-blocked-url?%s+%s+%s>" BANNER "</a>" "</center>" "</body>\n" "</html>\n" ;char CTRUST[] = "HTTP/1.0 202 Request for untrusted URL\n" "Pragma: no-cache\n" "Last-Modified: Thu Jul 31, 1997 07:42:22 pm GMT\n" "Expires: Thu Jul 31, 1997 07:42:22 pm GMT\n" "Content-Type: text/html\n\n" "<html>\n" "<head>\n" "<title>Internet Junkbuster: Request for untrusted URL</title>\n" "</head>\n" WHITEBG "<center>" "<a href=http://internet.junkbuster.com/ij-untrusted-url?%s+%s+%s>" BANNER "</a>" "</center>" "</body>\n" "</html>\n" ;char *block_url(struct http_request *http, struct client_state *csp){ struct file_list *fl; struct block_spec *b; struct url_spec url[1]; char *p; char *hostport, *path, *spec; int n; if(((fl = csp->blist) == NULL) || ((b = fl->f) == NULL)) { return(NULL); } *url = dsplit(http->host); /* if splitting the domain fails, punt */ if(url->dbuf == NULL) return(NULL); for(b = b->next; b ; b = b->next) { if((b->url->port == 0) || (b->url->port == http->port)) { if((b->url->domain[0] == '\0') || (domaincmp(b->url, url) == 0)) { if((b->url->path == NULL) ||#ifdef REGEX (regexec(b->url->preg, http->path, 0, NULL, 0) == 0)#else (strncmp(b->url->path, http->path, b->url->pathlen) == 0)#endif ) { freez(url->dbuf); freez(url->dvec); if(b->reject == 0) return(NULL); hostport = URL(http->hostport); path = URL(http->path); spec = URL(b->url->spec); n = strlen(CBLOCK); n += strlen(hostport); n += strlen(path); n += strlen(spec); p = malloc(n); sprintf(p, CBLOCK, hostport, path, spec); freez(hostport); freez(path); freez(spec); return(p); } } } } freez(url->dbuf); freez(url->dvec); return(NULL);}char *trust_url(struct http_request *http, struct client_state *csp){ struct file_list *fl; struct block_spec *b; struct url_spec url[1], **tl, *t; char *p, *h; char *hostport, *path, *referrer; struct http_request rhttp[1]; int n; if(((fl = csp->tlist) == NULL) || ((b = fl->f) == NULL)) { return(NULL); } *url = dsplit(http->host); /* if splitting the domain fails, punt */ if(url->dbuf == NULL) return(NULL); memset(rhttp, '\0', sizeof(*rhttp)); for(b = b->next; b ; b = b->next) { if((b->url->port == 0) || (b->url->port == http->port)) { if((b->url->domain[0] == '\0') || (domaincmp(b->url, url) == 0)) { if((b->url->path == NULL) ||#ifdef REGEX (regexec(b->url->preg, http->path, 0, NULL, 0) == 0)#else (strncmp(b->url->path, http->path, b->url->pathlen) == 0)#endif ) { freez(url->dbuf); freez(url->dvec); if(b->reject == 0) return(NULL); hostport = URL(http->hostport); path = URL(http->path); if(csp->referrer) { referrer = URL(csp->referrer); } else { referrer = URL("undefined"); } n = strlen(CTRUST); n += strlen(hostport); n += strlen(path); n += strlen(referrer); p = malloc(n); sprintf(p, CTRUST, hostport, path, referrer); freez(hostport); freez(path); freez(referrer); return(p); } } } } freez(url->dbuf); freez(url->dvec); if((csp->referrer == NULL)|| (strlen(csp->referrer) <= 9)) { /* no referrer was supplied */ goto trust_url_not_trusted; } /* forge a URL from the referrer so we can use * convert_url() to parse it into its components. */ p = NULL; p = strsav(p, "GET "); p = strsav(p, csp->referrer + 9); /* skip over "Referer: " */ p = strsav(p, " HTTP/1.0"); parse_http_request(p, rhttp, csp); if(rhttp->cmd == NULL) { freez(p); goto trust_url_not_trusted; } freez(p); *url = dsplit(rhttp->host); /* if splitting the domain fails, punt */ if(url->dbuf == NULL) goto trust_url_not_trusted; for(tl = trust_list; (t = *tl) ; tl++) { if((t->port == 0) || (t->port == rhttp->port)) { if((t->domain[0] == '\0') || domaincmp(t, url) == 0) { if((t->path == NULL) ||#ifdef REGEX (regexec(t->preg, rhttp->path, 0, NULL, 0) == 0)#else (strncmp(t->path, rhttp->path, t->pathlen) == 0)#endif ) { /* if the URL's referrer is from a trusted referrer, then * add the target spec to the trustfile as an unblocked * domain and return NULL (which means it's OK). */ FILE *fp; freez(url->dbuf); freez(url->dvec); if((fp = fopen(trustfile, "a"))) { h = NULL; h = strsav(h, "~"); h = strsav(h, http->hostport); p = http->path; if((*p++ == '/') && (*p++ == '~')) { /* since this path points into a user's home space * be sure to include this spec in the trustfile. */ if((p = strchr(p, '/'))) { *p = '\0'; h = strsav(h, http->path); h = strsav(h, "/"); } } free_http_request(rhttp); fprintf(fp, "%s\n", h); freez(h); fclose(fp); } return(NULL); } } } }trust_url_not_trusted: free_http_request(rhttp); hostport = URL(http->hostport); path = URL(http->path); if(csp->referrer) { referrer = URL(csp->referrer); } else { referrer = URL("undefined"); } n = strlen(CTRUST); n += strlen(hostport); n += strlen(path); n += strlen(referrer); p = malloc(n); sprintf(p, CTRUST, hostport, path, referrer); freez(hostport); freez(path); freez(referrer); return(p);}/* intercept_url() checks the URL `basename' against a list of URLs * to snarf. If it matches, it calls the associated function which * returns an HTML page to send back to the client. */char *intercept_url(struct http_request *http, struct client_state *csp){ char *basename; struct interceptors *v; basename = strrchr(http->path, '/'); if(basename == NULL) return(NULL); basename++; /* first char past the last slash */ if(*basename) { for(v = intercept_patterns; v->str; v++) { if(strncmp(basename, v->str, v->len) == 0) { return((v->interceptor)(http, csp)); } } } return(NULL);}struct cookie_spec *cookie_url(struct http_request *http, struct client_state *csp){ struct file_list *fl; struct cookie_spec *b; struct url_spec url[1]; if(((fl = csp->clist) == NULL) || ((b = fl->f) == NULL)) { return(NULL); } *url = dsplit(http->host); /* if splitting the domain fails, punt */ if(url->dbuf == NULL) return(NULL); for(b = b->next; b ; b = b->next) { if((b->url->port == 0) || (b->url->port == http->port)) { if((b->url->domain[0] == '\0') || (domaincmp(b->url, url) == 0)) { if((b->url->path == NULL) ||#ifdef REGEX (regexec(b->url->preg, http->path, 0, NULL, 0) == 0)#else (strncmp(b->url->path, http->path, b->url->pathlen) == 0)#endif ) { freez(url->dbuf); freez(url->dvec); return(b); } } } } freez(url->dbuf); freez(url->dvec); return(NULL);}struct gateway *forward_url(struct http_request *http, struct client_state *csp){ struct file_list *fl; struct forward_spec *b; struct url_spec url[1]; if(((fl = csp->flist) == NULL) || ((b = fl->f) == NULL)) { return(gw_default); } *url = dsplit(http->host); /* if splitting the domain fails, punt */ if(url->dbuf == NULL) return(gw_default); for(b = b->next; b ; b = b->next) { if((b->url->port == 0) || (b->url->port == http->port)) { if((b->url->domain[0] == '\0') || (domaincmp(b->url, url) == 0)) { if((b->url->path == NULL) ||#ifdef REGEX (regexec(b->url->preg, http->path, 0, NULL, 0) == 0)#else (strncmp(b->url->path, http->path, b->url->pathlen) == 0)#endif ) { freez(url->dbuf); freez(url->dvec); return(b->gw); } } } } freez(url->dbuf); freez(url->dvec); return(gw_default);}/* dsplit() takes a domain and returns a pointer to a url_spec * structure populated with dbuf, dcnt and dvec. the other fields * in the structure that is returned are zero. * */struct url_specdsplit(char *domain){ struct url_spec ret[1]; char *v[BUFSIZ]; int size; char *p; memset(ret, '\0', sizeof(*ret)); if((p = strrchr(domain, '.'))) { if(*(++p) == '\0') { ret->toplevel = 1; } } ret->dbuf = strdup(domain); /* map to lower case */ for(p = ret->dbuf; *p ; p++) *p = tolower(*p); /* split the domain name into components */ ret->dcnt = ssplit(ret->dbuf, ".", v, SZ(v), 1, 1); if(ret->dcnt <= 0) { memset(ret, '\0', sizeof(ret)); return(*ret); } /* save a copy of the pointers in dvec */ size = ret->dcnt * sizeof(*ret->dvec); if((ret->dvec = malloc(size))) { memcpy(ret->dvec, v, size); } return(*ret);}/* the "pattern" is a domain that may contain a '*' as a wildcard. * the "fqdn" is the domain name against which the patterns are compared. * * domaincmp("a.b.c" , "a.b.c") => 0 (MATCH) * domaincmp("a*.b.c", "a.b.c") => 0 (MATCH) * domaincmp("b.c" , "a.b.c") => 0 (MATCH) * domaincmp("" , "a.b.c") => 0 (MATCH) */intdomaincmp(struct url_spec *pattern, struct url_spec *fqdn){ char **pv, **fv; /* vectors */ int pn, fn; /* counters */ char *p, *f; /* chars */ pv = pattern->dvec; pn = pattern->dcnt; fv = fqdn->dvec; fn = fqdn->dcnt; while((pn > 0) && (fn > 0)) { p = pv[--pn]; f = fv[--fn]; while(*p && *f && (*p == tolower(*f))) { p++, f++; } if((*p != tolower(*f)) && (*p != '*')) return(1); } if(pn > 0) return(1); return(0);}/* intercept functions */char *show_proxy_args(struct http_request *http, struct client_state *csp){ char *s = NULL; s = strsav(s, proxy_args->header); s = strsav(s, proxy_args->invocation); s = strsav(s, proxy_args->gateways); if(csp->blist) { s = strsav(s, csp->blist->proxy_args); } if(csp->clist) { s = strsav(s, csp->clist->proxy_args); } if(csp->tlist) { s = strsav(s, csp->tlist->proxy_args); } if(csp->flist) { s = strsav(s, csp->flist->proxy_args); } s = strsav(s, proxy_args->trailer); return(s);}char *ij_blocked_url(struct http_request *http, struct client_state *csp){ int n; char *hostport, *path, *pattern, *p, *v[9]; char *template = "HTTP/1.0 200 OK\r\n" "Pragma: no-cache\n" "Last-Modified: Thu Jul 31, 1997 07:42:22 pm GMT\n" "Expires: Thu Jul 31, 1997 07:42:22 pm GMT\n" "Content-Type: text/html\n\n" "<html>\n" "<head>\n" "<title>Internet Junkbuster: Request for blocked URL</title>\n" "</head>\n" BODY "<center><h1>" BANNER "</h1></center>" "The " BANNER " Proxy " "<A href=\"http://internet.junkbuster.com\">" "(http://internet.junkbuster.com) </A>" "intercepted the request for %s%s\n" "because the URL matches the following pattern " "in the blockfile: %s\n" "</body>\n" "</html>\n" ; if((n = ssplit(http->path, "?+", v, SZ(v), 0, 0)) == 4) { hostport = url_decode(v[1]); path = url_decode(v[2]); pattern = url_decode(v[3]); } else { hostport = strdup("undefined_host"); path = strdup("/undefined_path"); pattern = strdup("undefined_pattern"); } n = strlen(template); n += strlen(hostport); n += strlen(path ); n += strlen(pattern ); if((p = malloc(n))) { sprintf(p, template, hostport, path, pattern); } freez(hostport); freez(path ); freez(pattern ); return(p);}char *ij_untrusted_url(struct http_request *http, struct client_state *csp){ int n; char *hostport, *path, *p, *v[9]; char buf[BUFSIZ]; struct url_spec **tl, *t; char *template = "HTTP/1.0 200 OK\r\n" "Pragma: no-cache\n" "Last-Modified: Thu Jul 31, 1997 07:42:22 pm GMT\n" "Expires: Thu Jul 31, 1997 07:42:22 pm GMT\n" "Content-Type: text/html\n\n" "<html>\n" "<head>\n" "<title>Internet Junkbuster: Request for untrusted URL</title>\n" "</head>\n" BODY "<center><h1>" BANNER "</h1></center>" "The " BANNER " Proxy " "<A href=\"http://internet.junkbuster.com\">" "(http://internet.junkbuster.com) </A>" "intercepted the request for %s%s\n" "because the URL is not trusted.\n" "<br><br>\n" ; if((n = ssplit(http->path, "?+", v, SZ(v), 0, 0)) == 4) { hostport = url_decode(v[1]); path = url_decode(v[2]); referrer = url_decode(v[3]); } else { hostport = strdup("undefined_host"); path = strdup("/undefined_path"); referrer = strdup("undefined"); } n = strlen(template); n += strlen(hostport); n += strlen(path ); if((p = malloc(n))) { sprintf(p, template, hostport, path); } freez(hostport); freez(path ); strsav(p, "The referrer in this request was <strong>"); strsav(p, referrer); strsav(p, "</strong><br>\n"); p = strsav(p, "<h3>The following referrers are trusted</h3>\n"); for(tl = trust_list; (t = *tl) ; tl++) { sprintf(buf, "%s<br>\n", t->spec); p = strsav(p, buf); } if(trust_info->next) { struct list *l; strcpy(buf, "<p>" "You can learn more about what this means " "and what you may be able to do about it by " "reading the following documents:<br>\n" "<ol>\n" ); p = strsav(p, buf); for(l = trust_info->next; l ; l = l->next) { sprintf(buf, "<li> <a href=%s>%s</a><br>\n", l->str, l->str); p = strsav(p, buf); } p = strsav(p, "</ol>\n"); } p = strsav(p, "</body>\n" "</html>\n"); return(p);}⌨️ 快捷键说明
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