/* * $LynxId: LYCgi.c,v 1.72 2018/03/18 18:56:05 tom Exp $ * Lynx CGI support LYCgi.c * ================ * * Authors * GL George Lindholm * * History * 15 Jun 95 Created as way to provide a lynx based service with * dynamic pages without the need for a http daemon. GL * 27 Jun 95 Added (command line) support. Various cleanup * and bug fixes. GL * 04 Sep 97 Added support for PATH_INFO scripts. JKT * * Bugs * If the called scripts aborts before sending the mime headers then * lynx hangs. * * Should do something about SIGPIPE, (but then it should never happen) * * No support for redirection. Or mime-types. * * Should try and parse for a HTTP 1.1 header in case we are "calling" a * nph- script. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static char **env = NULL; /* Environment variables */ static unsigned envc_size = 0; /* Slots in environment array */ static unsigned envc = 0; /* Slots used so far */ static HTList *alloced = NULL; #if defined(LYNXCGI_LINKS) && !defined(__MINGW32__) static char *user_agent = NULL; static char *server_software = NULL; static char *accept_language = NULL; static char *post_len = NULL; #endif /* LYNXCGI_LINKS */ static void add_environment_value(const char *env_value); #define PERROR(msg) CTRACE((tfp, "LYNXCGI: %s: %s\n", msg, LYStrerror(errno))) #define PUTS(buf) (*target->isa->put_block)(target, buf, strlen(buf)) #ifdef LY_FIND_LEAKS static void free_alloced_lynxcgi(void) { void *ptr; while ((ptr = HTList_removeLastObject(alloced)) != NULL) { FREE(ptr); } FREE(alloced); #ifdef LYNXCGI_LINKS FREE(user_agent); FREE(server_software); #endif } #endif /* LY_FIND_LEAKS */ static void remember_alloced(void *ptr) { if (!alloced) { alloced = HTList_new(); #ifdef LY_FIND_LEAKS atexit(free_alloced_lynxcgi); #endif } HTList_addObject(alloced, ptr); } /* * Simple routine for expanding the environment array and adding a value to * it */ static void add_environment_value(const char *env_value) { if (envc == envc_size) { /* Need some more slots */ envc_size += 10; if (env) { env = (char **) realloc(env, sizeof(env[0]) * (envc_size + 2)); /* + terminator and base 0 */ } else { env = (char **) malloc(sizeof(env[0]) * (envc_size + 2)); /* + terminator and base 0 */ remember_alloced(env); } if (env == NULL) { outofmem(__FILE__, "LYCgi"); } } env[envc++] = DeConst(env_value); env[envc] = NULL; /* Make sure it is always properly terminated */ } /* * Add the value of an existing environment variable to those passed on to the * lynxcgi script. */ void add_lynxcgi_environment(const char *variable_name) { char *env_value; env_value = LYGetEnv(variable_name); if (env_value != NULL) { char *add_value = NULL; HTSprintf0(&add_value, "%s=%s", variable_name, env_value); add_environment_value(add_value); remember_alloced(add_value); } } #ifdef __MINGW32__ static int LYLoadCGI(const char *arg, HTParentAnchor *anAnchor, HTFormat format_out, HTStream *sink) { (void) arg; (void) anAnchor; (void) format_out; (void) sink; return -1; } #else #ifdef LYNXCGI_LINKS /* * Wrapper for exec_ok(), confirming with user if the link text is not visible * in the status line. */ static BOOL can_exec_cgi(const char *linktext, const char *linkargs) { const char *format = gettext("Do you want to execute \"%s\"?"); char *message = NULL; char *command = NULL; char *p; BOOL result = TRUE; if (!exec_ok(HTLoadedDocumentURL(), linktext, CGI_PATH)) { /* exec_ok gives out msg. */ result = FALSE; } else { StrAllocCopy(command, linktext); if (non_empty(linkargs)) { HTSprintf(&command, " %s", linkargs); } HTUnEscape(command); for (p = command; *p; ++p) if (*p == '+') *p = ' '; HTSprintf0(&message, format, command); result = HTConfirm(message); FREE(message); FREE(command); } return result; } #endif /* LYNXCGI_LINKS */ static int LYLoadCGI(const char *arg, HTParentAnchor *anAnchor, HTFormat format_out, HTStream *sink) { int status = 0; #ifdef LYNXCGI_LINKS #ifndef VMS char *cp; struct stat stat_buf; char *pgm = NULL; /* executable */ char *pgm_args = NULL; /* and its argument(s) */ int statrv; char *orig_pgm = NULL; /* Path up to ? as given, URL-escaped */ char *document_root = NULL; /* Corrected value of DOCUMENT_ROOT */ char *path_info = NULL; /* PATH_INFO extracted from pgm */ char *pgm_buff = NULL; /* PATH_INFO extraction buffer */ char *path_translated; /* From document_root/path_info */ if (isEmpty(arg) || strlen(arg) <= 8) { HTAlert(BAD_REQUEST); status = -2; return (status); } else { if (StrNCmp(arg, "lynxcgi://localhost", 19) == 0) { StrAllocCopy(pgm, arg + 19); } else { StrAllocCopy(pgm, arg + 8); } if ((cp = StrChr(pgm, '?')) != NULL) { /* Need to terminate executable */ *cp++ = '\0'; pgm_args = cp; } } StrAllocCopy(orig_pgm, pgm); if (trimPoundSelector(pgm) != NULL) { /* * Strip a #fragment from path. In this case any pgm_args found above * will also be bogus, since the '?' came after the '#' and is part of * the fragment. Note that we don't handle the case where a '#' * appears after a '?' properly according to URL rules. - kw */ pgm_args = NULL; } HTUnEscape(pgm); /* BEGIN WebSter Mods */ /* If pgm is not stat-able, see if PATH_INFO data is at the end of pgm */ if ((statrv = stat(pgm, &stat_buf)) < 0) { StrAllocCopy(pgm_buff, pgm); while (statrv < 0 || (statrv = stat(pgm_buff, &stat_buf)) < 0) { if ((cp = strrchr(pgm_buff, '/')) != NULL) { *cp = '\0'; statrv = 1; /* force new stat() - kw */ } else { PERROR("strrchr(pgm_buff, '/') returned NULL"); break; } } if (statrv < 0) { /* Did not find PATH_INFO data */ PERROR("stat() of pgm_buff failed"); } else { /* Found PATH_INFO data. Strip it off of pgm and into path_info. */ StrAllocCopy(path_info, pgm + strlen(pgm_buff)); /* The following is safe since pgm_buff was derived from pgm by stripping stuff off its end and by HTUnEscaping, so we know we have enough memory allocated for pgm. Note that pgm_args may still point into that memory, so we cannot reallocate pgm here. - kw */ strcpy(pgm, pgm_buff); CTRACE((tfp, "LYNXCGI: stat() of %s succeeded, path_info=\"%s\".\n", pgm_buff, path_info)); } FREE(pgm_buff); } /* END WebSter Mods */ if (statrv != 0) { /* * Neither the path as given nor any components examined by backing up * were stat()able. - kw */ HTAlert(gettext("Unable to access cgi script")); PERROR("stat() failed"); status = -4; } else #ifdef _WINDOWS /* 1998/01/14 (Wed) 09:16:04 */ #define isExecutable(mode) (mode & (S_IXUSR)) #else #define isExecutable(mode) (mode & (S_IXUSR|S_IXGRP|S_IXOTH)) #endif if (!(S_ISREG(stat_buf.st_mode) && isExecutable(stat_buf.st_mode))) { /* * Not a runnable file, See if we can load it using "file:" code. */ char *new_arg = NULL; /* * But try "file:" only if the file we are looking at is the path as * given (no path_info was extracted), otherwise it will be to * confusing to know just what file is loaded. - kw */ if (path_info) { CTRACE((tfp, "%s is not a file and %s not an executable, giving up.\n", orig_pgm, pgm)); FREE(path_info); FREE(pgm); FREE(orig_pgm); status = -4; return (status); } LYLocalFileToURL(&new_arg, orig_pgm); CTRACE((tfp, "%s is not an executable file, passing the buck.\n", arg)); status = HTLoadFile(new_arg, anAnchor, format_out, sink); FREE(new_arg); } else if (path_info && anAnchor != HTMainAnchor && !(reloading && anAnchor->document) && strcmp(arg, HTLoadedDocumentURL()) && HText_AreDifferent(anAnchor, arg) && HTUnEscape(orig_pgm) && !can_exec_cgi(orig_pgm, "")) { /* * If we have extra path info and are not just reloading the current, * check the full file path (after unescaping) now to catch forbidden * segments. - kw */ status = HT_NOT_LOADED; } else if (no_lynxcgi) { HTUserMsg(CGI_DISABLED); status = HT_NOT_LOADED; } else if (no_bookmark_exec && anAnchor != HTMainAnchor && !(reloading && anAnchor->document) && strcmp(arg, HTLoadedDocumentURL()) && HText_AreDifferent(anAnchor, arg) && HTLoadedDocumentBookmark()) { /* * If we are reloading a lynxcgi document that had already been loaded, * the various checks above should allow it even if no_bookmark_exec is * TRUE an we are not now coming from a bookmark page. - kw */ HTUserMsg(BOOKMARK_EXEC_DISABLED); status = HT_NOT_LOADED; } else if (anAnchor != HTMainAnchor && !(reloading && anAnchor->document) && strcmp(arg, HTLoadedDocumentURL()) && HText_AreDifferent(anAnchor, arg) && !can_exec_cgi(pgm, pgm_args)) { /* * If we are reloading a lynxcgi document that had already been loaded, * the various checks above should allow it even if exec_ok() would * reject it because we are not now coming from a document with a URL * allowed by TRUSTED_LYNXCGI rules. - kw */ status = HT_NOT_LOADED; } else { HTFormat format_in; HTStream *target = NULL; /* Unconverted data */ int fd1[2], fd2[2]; char buf[MAX_LINE]; int pid; #ifdef HAVE_TYPE_UNIONWAIT union wait wstatus; #else int wstatus; #endif fd1[0] = -1; fd1[1] = -1; fd2[0] = -1; fd2[1] = -1; if (anAnchor->isHEAD || keep_mime_headers) { /* Show output as plain text */ format_in = WWW_PLAINTEXT; } else { /* Decode full HTTP response */ format_in = HTAtom_for("www/mime"); } target = HTStreamStack(format_in, format_out, sink, anAnchor); if (target == NULL) { char *tmp = 0; HTSprintf0(&tmp, CANNOT_CONVERT_I_TO_O, HTAtom_name(format_in), HTAtom_name(format_out)); HTAlert(tmp); FREE(tmp); status = HT_NOT_LOADED; } else if (anAnchor->post_data && pipe(fd1) < 0) { HTAlert(CONNECT_SET_FAILED); PERROR("pipe() failed"); status = -3; } else if (pipe(fd2) < 0) { HTAlert(CONNECT_SET_FAILED); PERROR("pipe() failed"); close(fd1[0]); close(fd1[1]); status = -3; } else { static BOOL first_time = TRUE; /* One time setup flag */ if (first_time) { /* Set up static environment variables */ first_time = FALSE; /* Only once */ add_environment_value("REMOTE_HOST=localhost"); add_environment_value("REMOTE_ADDR=127.0.0.1"); HTSprintf0(&user_agent, "HTTP_USER_AGENT=%s/%s libwww/%s", LYNX_NAME, LYNX_VERSION, HTLibraryVersion); add_environment_value(user_agent); HTSprintf0(&server_software, "SERVER_SOFTWARE=%s/%s", LYNX_NAME, LYNX_VERSION); add_environment_value(server_software); } fflush(stdout); fflush(stderr); CTRACE_FLUSH(tfp); if ((pid = fork()) > 0) { /* The good, */ ssize_t chars; off_t total_chars; close(fd2[1]); if (anAnchor->post_data) { ssize_t written; int remaining, total_written = 0; close(fd1[0]); /* We have form data to push across the pipe */ if (TRACE) { CTRACE((tfp, "LYNXCGI: Doing post, content-type '%s'\n", anAnchor->post_content_type)); CTRACE((tfp, "LYNXCGI: Writing:\n")); trace_bstring(anAnchor->post_data); CTRACE((tfp, "----------------------------------\n")); } remaining = BStrLen(anAnchor->post_data); while ((written = write(fd1[1], BStrData(anAnchor->post_data) + total_written, (size_t) remaining)) != 0) { if (written < 0) { #ifdef EINTR if (errno == EINTR) continue; #endif /* EINTR */ #ifdef ERESTARTSYS if (errno == ERESTARTSYS) continue; #endif /* ERESTARTSYS */ PERROR("write() of POST data failed"); break; } CTRACE((tfp, "LYNXCGI: Wrote %d bytes of POST data.\n", (int) written)); total_written += (int) written; remaining -= (int) written; if (remaining == 0) break; } if (remaining != 0) { CTRACE((tfp, "LYNXCGI: %d bytes remain unwritten!\n", remaining)); } close(fd1[1]); } HTReadProgress(total_chars = 0, (off_t) 0); while ((chars = read(fd2[0], buf, sizeof(buf))) != 0) { if (chars < 0) { #ifdef EINTR if (errno == EINTR) continue; #endif /* EINTR */ #ifdef ERESTARTSYS if (errno == ERESTARTSYS) continue; #endif /* ERESTARTSYS */ PERROR("read() of CGI output failed"); break; } total_chars += (int) chars; HTReadProgress(total_chars, (off_t) 0); CTRACE((tfp, "LYNXCGI: Rx: %.*s\n", (int) chars, buf)); (*target->isa->put_block) (target, buf, (int) chars); } if (chars < 0 && total_chars == 0) { status = HT_NOT_LOADED; (*target->isa->_abort) (target, NULL); target = NULL; } else if (chars != 0) { status = HT_PARTIAL_CONTENT; } else { status = HT_LOADED; } #ifndef HAVE_WAITPID while (wait(&wstatus) != pid) ; /* do nothing */ #else while (-1 == waitpid(pid, &wstatus, 0)) { /* wait for child */ #ifdef EINTR if (errno == EINTR) continue; #endif /* EINTR */ #ifdef ERESTARTSYS if (errno == ERESTARTSYS) continue; #endif /* ERESTARTSYS */ break; } #endif /* !HAVE_WAITPID */ close(fd2[0]); } else if (pid == 0) { /* The Bad, */ char **argv = NULL; int argv_cnt = 3; /* name, one arg and terminator */ char **cur_argv = NULL; int exec_errno; /* Set up output pipe */ close(fd2[0]); dup2(fd2[1], fileno(stdout)); /* Should check success code */ dup2(fd2[1], fileno(stderr)); close(fd2[1]); if (non_empty(language)) { HTSprintf0(&accept_language, "HTTP_ACCEPT_LANGUAGE=%s", language); add_environment_value(accept_language); } if (non_empty(pref_charset)) { cp = NULL; StrAllocCopy(cp, "HTTP_ACCEPT_CHARSET="); StrAllocCat(cp, pref_charset); add_environment_value(cp); } if (anAnchor->post_data && anAnchor->post_content_type) { cp = NULL; StrAllocCopy(cp, "CONTENT_TYPE="); StrAllocCat(cp, anAnchor->post_content_type); add_environment_value(cp); } if (anAnchor->post_data) { /* post script, read stdin */ close(fd1[1]); dup2(fd1[0], fileno(stdin)); close(fd1[0]); /* Build environment variables */ add_environment_value("REQUEST_METHOD=POST"); HTSprintf0(&post_len, "CONTENT_LENGTH=%d", BStrLen(anAnchor->post_data)); add_environment_value(post_len); } else { close(fileno(stdin)); if (anAnchor->isHEAD) { add_environment_value("REQUEST_METHOD=HEAD"); } } /* * Set up argument line, mainly for scripts */ if (pgm_args != NULL) { for (cp = pgm_args; *cp != '\0'; cp++) { if (*cp == '+') { argv_cnt++; } } } argv = (char **) malloc((unsigned) argv_cnt * sizeof(char *)); if (argv == NULL) { outofmem(__FILE__, "LYCgi"); } cur_argv = argv + 1; /* For argv[0] */ if (pgm_args != NULL) { char *cr; /* Data for a get/search form */ if (is_www_index) { add_environment_value("REQUEST_METHOD=SEARCH"); } else if (!anAnchor->isHEAD && !anAnchor->post_data) { add_environment_value("REQUEST_METHOD=GET"); } cp = NULL; StrAllocCopy(cp, "QUERY_STRING="); StrAllocCat(cp, pgm_args); add_environment_value(cp); /* * Split up arguments into argv array */ cp = pgm_args; cr = cp; while (1) { if (*cp == '\0') { *(cur_argv++) = HTUnEscape(cr); break; } else if (*cp == '+') { *cp++ = '\0'; *(cur_argv++) = HTUnEscape(cr); cr = cp; } cp++; } } else if (!anAnchor->isHEAD && !anAnchor->post_data) { add_environment_value("REQUEST_METHOD=GET"); } *cur_argv = NULL; /* Terminate argv */ argv[0] = pgm; /* Begin WebSter Mods -jkt */ if (non_empty(LYCgiDocumentRoot)) { /* Add DOCUMENT_ROOT to env */ cp = NULL; StrAllocCopy(cp, "DOCUMENT_ROOT="); StrAllocCat(cp, LYCgiDocumentRoot); add_environment_value(cp); } if (path_info != NULL) { /* Add PATH_INFO to env */ cp = NULL; StrAllocCopy(cp, "PATH_INFO="); StrAllocCat(cp, path_info); add_environment_value(cp); } if (non_empty(LYCgiDocumentRoot) && path_info != NULL) { /* Construct and add PATH_TRANSLATED to env */ StrAllocCopy(document_root, LYCgiDocumentRoot); LYTrimHtmlSep(document_root); path_translated = document_root; StrAllocCat(path_translated, path_info); cp = NULL; StrAllocCopy(cp, "PATH_TRANSLATED="); StrAllocCat(cp, path_translated); add_environment_value(cp); FREE(path_translated); } /* End WebSter Mods -jkt */ execve(argv[0], argv, env); exec_errno = errno; PERROR("execve failed"); printf("Content-Type: " STR_PLAINTEXT "\r\n\r\n"); if (!anAnchor->isHEAD) { printf("exec of %s failed", pgm); printf(": %s.\r\n", LYStrerror(exec_errno)); } fflush(stdout); fflush(stderr); _exit(1); } else { /* and the Ugly */ HTAlert(CONNECT_FAILED); PERROR("fork() failed"); close(fd1[0]); close(fd1[1]); close(fd2[0]); close(fd2[1]); status = -1; } } if (target != NULL) { (*target->isa->_free) (target); } } FREE(path_info); FREE(pgm); FREE(orig_pgm); #else /* VMS */ HTStream *target; char *buf = 0; target = HTStreamStack(WWW_HTML, format_out, sink, anAnchor); HTSprintf0(&buf, "\n\n%s\n\n\n", gettext("Good Advice")); PUTS(buf); HTSprintf0(&buf, "

%s

\n", gettext("Good Advice")); PUTS(buf); HTSprintf0(&buf, "%s %s.\n", gettext("this link")); PUTS(buf); HTSprintf0(&buf, "

%s\n", gettext("It provides state of the art CGI script support.\n")); PUTS(buf); HTSprintf0(&buf, "\n\n"); PUTS(buf); (*target->isa->_free) (target); FREE(buf); status = HT_LOADED; #endif /* VMS */ #else /* LYNXCGI_LINKS */ HTUserMsg(CGI_NOT_COMPILED); status = HT_NOT_LOADED; #endif /* LYNXCGI_LINKS */ (void) arg; (void) anAnchor; (void) format_out; (void) sink; return (status); } #endif /* __MINGW32__ */ #ifdef GLOBALDEF_IS_MACRO #define _LYCGI_C_GLOBALDEF_1_INIT { "lynxcgi", LYLoadCGI, 0 } GLOBALDEF(HTProtocol, LYLynxCGI, _LYCGI_C_GLOBALDEF_1_INIT); #else GLOBALDEF HTProtocol LYLynxCGI = {"lynxcgi", LYLoadCGI, 0}; #endif /* GLOBALDEF_IS_MACRO */