/* $OpenBSD: cgi.c,v 1.41 2014/11/26 00:57:32 schwarze Exp $ */ /* * Copyright (c) 2011, 2012 Kristaps Dzonsons * Copyright (c) 2014 Ingo Schwarze * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include #include #include #include "mandoc.h" #include "mandoc_aux.h" #include "main.h" #include "manpath.h" #include "mansearch.h" #include "cgi.h" /* * A query as passed to the search function. */ struct query { char *manpath; /* desired manual directory */ char *arch; /* architecture */ char *sec; /* manual section */ char *query; /* unparsed query expression */ int equal; /* match whole names, not substrings */ }; struct req { struct query q; char **p; /* array of available manpaths */ size_t psz; /* number of available manpaths */ }; static void catman(const struct req *, const char *); static void format(const struct req *, const char *); static void html_print(const char *); static void html_putchar(char); static int http_decode(char *); static void http_parse(struct req *, const char *); static void http_print(const char *); static void http_putchar(char); static void http_printquery(const struct req *, const char *); static void pathgen(struct req *); static void pg_error_badrequest(const char *); static void pg_error_internal(void); static void pg_index(const struct req *); static void pg_noresult(const struct req *, const char *); static void pg_search(const struct req *); static void pg_searchres(const struct req *, struct manpage *, size_t); static void pg_show(struct req *, const char *); static void resp_begin_html(int, const char *); static void resp_begin_http(int, const char *); static void resp_end_html(void); static void resp_searchform(const struct req *); static void resp_show(const struct req *, const char *); static void set_query_attr(char **, char **); static int validate_filename(const char *); static int validate_manpath(const struct req *, const char *); static int validate_urifrag(const char *); static const char *scriptname; /* CGI script name */ static const int sec_prios[] = {1, 4, 5, 8, 6, 3, 7, 2, 9}; static const char *const sec_numbers[] = { "0", "1", "2", "3", "3p", "4", "5", "6", "7", "8", "9" }; static const char *const sec_names[] = { "All Sections", "1 - General Commands", "2 - System Calls", "3 - Library Functions", "3p - Perl Library", "4 - Device Drivers", "5 - File Formats", "6 - Games", "7 - Miscellaneous Information", "8 - System Manager\'s Manual", "9 - Kernel Developer\'s Manual" }; static const int sec_MAX = sizeof(sec_names) / sizeof(char *); static const char *const arch_names[] = { "amd64", "alpha", "armish", "armv7", "aviion", "hppa", "hppa64", "i386", "ia64", "landisk", "loongson", "luna88k", "macppc", "mips64", "octeon", "sgi", "socppc", "solbourne", "sparc", "sparc64", "vax", "zaurus", "amiga", "arc", "arm32", "atari", "beagle", "cats", "hp300", "mac68k", "mvme68k", "mvme88k", "mvmeppc", "palm", "pc532", "pegasos", "pmax", "powerpc", "sun3", "wgrisc", "x68k" }; static const int arch_MAX = sizeof(arch_names) / sizeof(char *); /* * Print a character, escaping HTML along the way. * This will pass non-ASCII straight to output: be warned! */ static void html_putchar(char c) { switch (c) { case ('"'): printf(""e;"); break; case ('&'): printf("&"); break; case ('>'): printf(">"); break; case ('<'): printf("<"); break; default: putchar((unsigned char)c); break; } } static void http_printquery(const struct req *req, const char *sep) { if (NULL != req->q.query) { printf("query="); http_print(req->q.query); } if (0 == req->q.equal) printf("%sapropos=1", sep); if (NULL != req->q.sec) { printf("%ssec=", sep); http_print(req->q.sec); } if (NULL != req->q.arch) { printf("%sarch=", sep); http_print(req->q.arch); } if (strcmp(req->q.manpath, req->p[0])) { printf("%smanpath=", sep); http_print(req->q.manpath); } } static void http_print(const char *p) { if (NULL == p) return; while ('\0' != *p) http_putchar(*p++); } /* * Call through to html_putchar(). * Accepts NULL strings. */ static void html_print(const char *p) { if (NULL == p) return; while ('\0' != *p) html_putchar(*p++); } /* * Transfer the responsibility for the allocated string *val * to the query structure. */ static void set_query_attr(char **attr, char **val) { free(*attr); if (**val == '\0') { *attr = NULL; free(*val); } else *attr = *val; *val = NULL; } /* * Parse the QUERY_STRING for key-value pairs * and store the values into the query structure. */ static void http_parse(struct req *req, const char *qs) { char *key, *val; size_t keysz, valsz; req->q.manpath = NULL; req->q.arch = NULL; req->q.sec = NULL; req->q.query = NULL; req->q.equal = 1; key = val = NULL; while (*qs != '\0') { /* Parse one key. */ keysz = strcspn(qs, "=;&"); key = mandoc_strndup(qs, keysz); qs += keysz; if (*qs != '=') goto next; /* Parse one value. */ valsz = strcspn(++qs, ";&"); val = mandoc_strndup(qs, valsz); qs += valsz; /* Decode and catch encoding errors. */ if ( ! (http_decode(key) && http_decode(val))) goto next; /* Handle key-value pairs. */ if ( ! strcmp(key, "query")) set_query_attr(&req->q.query, &val); else if ( ! strcmp(key, "apropos")) req->q.equal = !strcmp(val, "0"); else if ( ! strcmp(key, "manpath")) { #ifdef COMPAT_OLDURI if ( ! strncmp(val, "OpenBSD ", 8)) { val[7] = '-'; if ('C' == val[8]) val[8] = 'c'; } #endif set_query_attr(&req->q.manpath, &val); } else if ( ! (strcmp(key, "sec") #ifdef COMPAT_OLDURI && strcmp(key, "sektion") #endif )) { if ( ! strcmp(val, "0")) *val = '\0'; set_query_attr(&req->q.sec, &val); } else if ( ! strcmp(key, "arch")) { if ( ! strcmp(val, "default")) *val = '\0'; set_query_attr(&req->q.arch, &val); } /* * The key must be freed in any case. * The val may have been handed over to the query * structure, in which case it is now NULL. */ next: free(key); key = NULL; free(val); val = NULL; if (*qs != '\0') qs++; } } static void http_putchar(char c) { if (isalnum((unsigned char)c)) { putchar((unsigned char)c); return; } else if (' ' == c) { putchar('+'); return; } printf("%%%.2x", c); } /* * HTTP-decode a string. The standard explanation is that this turns * "%4e+foo" into "n foo" in the regular way. This is done in-place * over the allocated string. */ static int http_decode(char *p) { char hex[3]; char *q; int c; hex[2] = '\0'; q = p; for ( ; '\0' != *p; p++, q++) { if ('%' == *p) { if ('\0' == (hex[0] = *(p + 1))) return(0); if ('\0' == (hex[1] = *(p + 2))) return(0); if (1 != sscanf(hex, "%x", &c)) return(0); if ('\0' == c) return(0); *q = (char)c; p += 2; } else *q = '+' == *p ? ' ' : *p; } *q = '\0'; return(1); } static void resp_begin_http(int code, const char *msg) { if (200 != code) printf("Status: %d %s\r\n", code, msg); printf("Content-Type: text/html; charset=utf-8\r\n" "Cache-Control: no-cache\r\n" "Pragma: no-cache\r\n" "\r\n"); fflush(stdout); } static void resp_begin_html(int code, const char *msg) { resp_begin_http(code, msg); printf("\n" "\n" "\n" "\n" "\n" "\n" "%s\n" "\n" "\n" "\n", CSS_DIR, CSS_DIR, CUSTOMIZE_TITLE); } static void resp_end_html(void) { puts("\n" ""); } static void resp_searchform(const struct req *req) { int i; puts(CUSTOMIZE_BEGIN); puts(""); printf("
\n" "
\n" "
\n" "Manual Page Search Parameters\n", scriptname); /* Write query input box. */ printf( "
\n" "q.query) html_print(req->q.query); puts("\" SIZE=\"40\">"); /* Write submission and reset buttons. */ printf( "\n" "\n"); /* Write show radio button */ printf( "\n" "q.equal) printf("CHECKED=\"checked\" "); printf( "NAME=\"apropos\" ID=\"show\" VALUE=\"0\">\n" "\n"); /* Write section selector. */ puts( "
\n" ""); /* Write architecture selector. */ printf( ""); /* Write manpath selector. */ if (req->psz > 1) { puts(""); } /* Write search radio button */ printf( "\n" "q.equal) printf("CHECKED=\"checked\" "); printf( "NAME=\"apropos\" ID=\"search\" VALUE=\"1\">\n" "\n"); puts("
\n" "
\n" "
\n" "
"); puts(""); } static int validate_urifrag(const char *frag) { while ('\0' != *frag) { if ( ! (isalnum((unsigned char)*frag) || '-' == *frag || '.' == *frag || '/' == *frag || '_' == *frag)) return(0); frag++; } return(1); } static int validate_manpath(const struct req *req, const char* manpath) { size_t i; if ( ! strcmp(manpath, "mandoc")) return(1); for (i = 0; i < req->psz; i++) if ( ! strcmp(manpath, req->p[i])) return(1); return(0); } static int validate_filename(const char *file) { if ('.' == file[0] && '/' == file[1]) file += 2; return ( ! (strstr(file, "../") || strstr(file, "/..") || (strncmp(file, "man", 3) && strncmp(file, "cat", 3)))); } static void pg_index(const struct req *req) { resp_begin_html(200, NULL); resp_searchform(req); printf("

\n" "This web interface is documented in the\n" "man.cgi\n" "manual, and the\n" "apropos\n" "manual explains the query syntax.\n" "

\n", scriptname, scriptname); resp_end_html(); } static void pg_noresult(const struct req *req, const char *msg) { resp_begin_html(200, NULL); resp_searchform(req); puts("

"); puts(msg); puts("

"); resp_end_html(); } static void pg_error_badrequest(const char *msg) { resp_begin_html(400, "Bad Request"); puts("

Bad Request

\n" "

\n"); puts(msg); printf("Try again from the\n" "main page.\n" "

", scriptname); resp_end_html(); } static void pg_error_internal(void) { resp_begin_html(500, "Internal Server Error"); puts("

Internal Server Error

"); resp_end_html(); } static void pg_searchres(const struct req *req, struct manpage *r, size_t sz) { char *arch, *archend; size_t i, iuse, isec; int archprio, archpriouse; int prio, priouse; char sec; for (i = 0; i < sz; i++) { if (validate_filename(r[i].file)) continue; fprintf(stderr, "invalid filename %s in %s database\n", r[i].file, req->q.manpath); pg_error_internal(); return; } if (1 == sz) { /* * If we have just one result, then jump there now * without any delay. */ printf("Status: 303 See Other\r\n"); printf("Location: http://%s%s/%s/%s?", HTTP_HOST, scriptname, req->q.manpath, r[0].file); http_printquery(req, "&"); printf("\r\n" "Content-Type: text/html; charset=utf-8\r\n" "\r\n"); return; } resp_begin_html(200, NULL); resp_searchform(req); puts("
"); puts(""); for (i = 0; i < sz; i++) { printf("\n" "\n" "\n" ""); } puts("
\n" "q.manpath, r[i].file); http_printquery(req, "&"); printf("\">"); html_print(r[i].names); printf("\n" ""); html_print(r[i].output); puts("
\n" "
"); /* * In man(1) mode, show one of the pages * even if more than one is found. */ if (req->q.equal) { puts("
"); iuse = 0; priouse = 10; archpriouse = 3; for (i = 0; i < sz; i++) { isec = strcspn(r[i].file, "123456789"); sec = r[i].file[isec]; if ('\0' == sec) continue; prio = sec_prios[sec - '1']; if (NULL == req->q.arch) { archprio = (NULL == (arch = strchr( r[i].file + isec, '/'))) ? 3 : (NULL == (archend = strchr( arch + 1, '/'))) ? 0 : strncmp(arch, "amd64/", archend - arch) ? 2 : 1; if (archprio < archpriouse) { archpriouse = archprio; priouse = prio; iuse = i; continue; } if (archprio > archpriouse) continue; } if (prio >= priouse) continue; priouse = prio; iuse = i; } resp_show(req, r[iuse].file); } resp_end_html(); } static void catman(const struct req *req, const char *file) { FILE *f; size_t len; int i; char *p; int italic, bold; if (NULL == (f = fopen(file, "r"))) { puts("

You specified an invalid manual file.

"); return; } puts("
\n" "
");

	while (NULL != (p = fgetln(f, &len))) {
		bold = italic = 0;
		for (i = 0; i < (int)len - 1; i++) {
			/* 
			 * This means that the catpage is out of state.
			 * Ignore it and keep going (although the
			 * catpage is bogus).
			 */

			if ('\b' == p[i] || '\n' == p[i])
				continue;

			/*
			 * Print a regular character.
			 * Close out any bold/italic scopes.
			 * If we're in back-space mode, make sure we'll
			 * have something to enter when we backspace.
			 */

			if ('\b' != p[i + 1]) {
				if (italic)
					printf("");
				if (bold)
					printf("");
				italic = bold = 0;
				html_putchar(p[i]);
				continue;
			} else if (i + 2 >= (int)len)
				continue;

			/* Italic mode. */

			if ('_' == p[i]) {
				if (bold)
					printf("");
				if ( ! italic)
					printf("");
				bold = 0;
				italic = 1;
				i += 2;
				html_putchar(p[i]);
				continue;
			}

			/* 
			 * Handle funny behaviour troff-isms.
			 * These grok'd from the original man2html.c.
			 */

			if (('+' == p[i] && 'o' == p[i + 2]) ||
					('o' == p[i] && '+' == p[i + 2]) ||
					('|' == p[i] && '=' == p[i + 2]) ||
					('=' == p[i] && '|' == p[i + 2]) ||
					('*' == p[i] && '=' == p[i + 2]) ||
					('=' == p[i] && '*' == p[i + 2]) ||
					('*' == p[i] && '|' == p[i + 2]) ||
					('|' == p[i] && '*' == p[i + 2]))  {
				if (italic)
					printf("");
				if (bold)
					printf("");
				italic = bold = 0;
				putchar('*');
				i += 2;
				continue;
			} else if (('|' == p[i] && '-' == p[i + 2]) ||
					('-' == p[i] && '|' == p[i + 1]) ||
					('+' == p[i] && '-' == p[i + 1]) ||
					('-' == p[i] && '+' == p[i + 1]) ||
					('+' == p[i] && '|' == p[i + 1]) ||
					('|' == p[i] && '+' == p[i + 1]))  {
				if (italic)
					printf("");
				if (bold)
					printf("");
				italic = bold = 0;
				putchar('+');
				i += 2;
				continue;
			}

			/* Bold mode. */
			
			if (italic)
				printf("");
			if ( ! bold)
				printf("");
			bold = 1;
			italic = 0;
			i += 2;
			html_putchar(p[i]);
		}

		/* 
		 * Clean up the last character.
		 * We can get to a newline; don't print that. 
		 */

		if (italic)
			printf("");
		if (bold)
			printf("");

		if (i == (int)len - 1 && '\n' != p[i])
			html_putchar(p[i]);

		putchar('\n');
	}

	puts("
\n" "
"); fclose(f); } static void format(const struct req *req, const char *file) { struct mparse *mp; struct mchars *mchars; struct mdoc *mdoc; struct man *man; void *vp; char *opts; enum mandoclevel rc; int fd; int usepath; if (-1 == (fd = open(file, O_RDONLY, 0))) { puts("

You specified an invalid manual file.

"); return; } mchars = mchars_alloc(); mp = mparse_alloc(MPARSE_SO, MANDOCLEVEL_FATAL, NULL, mchars, req->q.manpath); rc = mparse_readfd(mp, fd, file); close(fd); if (rc >= MANDOCLEVEL_FATAL) { fprintf(stderr, "fatal mandoc error: %s/%s\n", req->q.manpath, file); pg_error_internal(); return; } usepath = strcmp(req->q.manpath, req->p[0]); mandoc_asprintf(&opts, "fragment,man=%s?query=%%N&sec=%%S%s%s%s%s", scriptname, req->q.arch ? "&arch=" : "", req->q.arch ? req->q.arch : "", usepath ? "&manpath=" : "", usepath ? req->q.manpath : ""); mparse_result(mp, &mdoc, &man, NULL); if (NULL == man && NULL == mdoc) { fprintf(stderr, "fatal mandoc error: %s/%s\n", req->q.manpath, file); pg_error_internal(); mparse_free(mp); mchars_free(mchars); return; } vp = html_alloc(mchars, opts); if (NULL != mdoc) html_mdoc(vp, mdoc); else html_man(vp, man); html_free(vp); mparse_free(mp); mchars_free(mchars); free(opts); } static void resp_show(const struct req *req, const char *file) { if ('.' == file[0] && '/' == file[1]) file += 2; if ('c' == *file) catman(req, file); else format(req, file); } static void pg_show(struct req *req, const char *fullpath) { char *manpath; const char *file; if ((file = strchr(fullpath, '/')) == NULL) { pg_error_badrequest( "You did not specify a page to show."); return; } manpath = mandoc_strndup(fullpath, file - fullpath); file++; if ( ! validate_manpath(req, manpath)) { pg_error_badrequest( "You specified an invalid manpath."); free(manpath); return; } /* * Begin by chdir()ing into the manpath. * This way we can pick up the database files, which are * relative to the manpath root. */ if (chdir(manpath) == -1) { fprintf(stderr, "chdir %s: %s\n", manpath, strerror(errno)); pg_error_internal(); free(manpath); return; } if (strcmp(manpath, "mandoc")) { free(req->q.manpath); req->q.manpath = manpath; } else free(manpath); if ( ! validate_filename(file)) { pg_error_badrequest( "You specified an invalid manual file."); return; } resp_begin_html(200, NULL); resp_searchform(req); resp_show(req, file); resp_end_html(); } static void pg_search(const struct req *req) { struct mansearch search; struct manpaths paths; struct manpage *res; char **argv; char *query, *rp, *wp; size_t ressz; int argc; /* * Begin by chdir()ing into the root of the manpath. * This way we can pick up the database files, which are * relative to the manpath root. */ if (-1 == (chdir(req->q.manpath))) { fprintf(stderr, "chdir %s: %s\n", req->q.manpath, strerror(errno)); pg_error_internal(); return; } search.arch = req->q.arch; search.sec = req->q.sec; search.outkey = "Nd"; search.argmode = req->q.equal ? ARG_NAME : ARG_EXPR; search.firstmatch = 1; paths.sz = 1; paths.paths = mandoc_malloc(sizeof(char *)); paths.paths[0] = mandoc_strdup("."); /* * Break apart at spaces with backslash-escaping. */ argc = 0; argv = NULL; rp = query = mandoc_strdup(req->q.query); for (;;) { while (isspace((unsigned char)*rp)) rp++; if (*rp == '\0') break; argv = mandoc_reallocarray(argv, argc + 1, sizeof(char *)); argv[argc++] = wp = rp; for (;;) { if (isspace((unsigned char)*rp)) { *wp = '\0'; rp++; break; } if (rp[0] == '\\' && rp[1] != '\0') rp++; if (wp != rp) *wp = *rp; if (*rp == '\0') break; wp++; rp++; } } if (0 == mansearch(&search, &paths, argc, argv, &res, &ressz)) pg_noresult(req, "You entered an invalid query."); else if (0 == ressz) pg_noresult(req, "No results found."); else pg_searchres(req, res, ressz); free(query); mansearch_free(res, ressz); free(paths.paths[0]); free(paths.paths); } int main(void) { struct req req; struct itimerval itimer; const char *path; const char *querystring; int i; /* Poor man's ReDoS mitigation. */ itimer.it_value.tv_sec = 2; itimer.it_value.tv_usec = 0; itimer.it_interval.tv_sec = 2; itimer.it_interval.tv_usec = 0; if (setitimer(ITIMER_VIRTUAL, &itimer, NULL) == -1) { fprintf(stderr, "setitimer: %s\n", strerror(errno)); pg_error_internal(); return(EXIT_FAILURE); } /* Scan our run-time environment. */ if (NULL == (scriptname = getenv("SCRIPT_NAME"))) scriptname = ""; if ( ! validate_urifrag(scriptname)) { fprintf(stderr, "unsafe SCRIPT_NAME \"%s\"\n", scriptname); pg_error_internal(); return(EXIT_FAILURE); } /* * First we change directory into the MAN_DIR so that * subsequent scanning for manpath directories is rooted * relative to the same position. */ if (-1 == chdir(MAN_DIR)) { fprintf(stderr, "MAN_DIR: %s: %s\n", MAN_DIR, strerror(errno)); pg_error_internal(); return(EXIT_FAILURE); } memset(&req, 0, sizeof(struct req)); pathgen(&req); /* Next parse out the query string. */ if (NULL != (querystring = getenv("QUERY_STRING"))) http_parse(&req, querystring); if (req.q.manpath == NULL) req.q.manpath = mandoc_strdup(req.p[0]); else if ( ! validate_manpath(&req, req.q.manpath)) { pg_error_badrequest( "You specified an invalid manpath."); return(EXIT_FAILURE); } if ( ! (NULL == req.q.arch || validate_urifrag(req.q.arch))) { pg_error_badrequest( "You specified an invalid architecture."); return(EXIT_FAILURE); } /* Dispatch to the three different pages. */ path = getenv("PATH_INFO"); if (NULL == path) path = ""; else if ('/' == *path) path++; if ('\0' != *path) pg_show(&req, path); else if (NULL != req.q.query) pg_search(&req); else pg_index(&req); free(req.q.manpath); free(req.q.arch); free(req.q.sec); free(req.q.query); for (i = 0; i < (int)req.psz; i++) free(req.p[i]); free(req.p); return(EXIT_SUCCESS); } /* * Scan for indexable paths. */ static void pathgen(struct req *req) { FILE *fp; char *dp; size_t dpsz; if (NULL == (fp = fopen("manpath.conf", "r"))) { fprintf(stderr, "%s/manpath.conf: %s\n", MAN_DIR, strerror(errno)); pg_error_internal(); exit(EXIT_FAILURE); } while (NULL != (dp = fgetln(fp, &dpsz))) { if ('\n' == dp[dpsz - 1]) dpsz--; req->p = mandoc_realloc(req->p, (req->psz + 1) * sizeof(char *)); dp = mandoc_strndup(dp, dpsz); if ( ! validate_urifrag(dp)) { fprintf(stderr, "%s/manpath.conf contains " "unsafe path \"%s\"\n", MAN_DIR, dp); pg_error_internal(); exit(EXIT_FAILURE); } if (NULL != strchr(dp, '/')) { fprintf(stderr, "%s/manpath.conf contains " "path with slash \"%s\"\n", MAN_DIR, dp); pg_error_internal(); exit(EXIT_FAILURE); } req->p[req->psz++] = dp; } if ( req->p == NULL ) { fprintf(stderr, "%s/manpath.conf is empty\n", MAN_DIR); pg_error_internal(); exit(EXIT_FAILURE); } }