/*
* $LynxId: LYCgi.c,v 1.72 2018/03/18 18:56:05 tom Exp $
* Lynx CGI support LYCgi.c
* ================
*
* Authors
* GL George Lindholm <George.Lindholm@ubc.ca>
*
* 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 <index> (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 <HTUtils.h>
#include <HTTP.h>
#include <HTParse.h>
#include <HTTCP.h>
#include <HTFormat.h>
#include <HTFile.h>
#include <HTAlert.h>
#include <HTMIME.h>
#include <HTAABrow.h>
#include <LYGlobalDefs.h>
#include <LYUtils.h>
#include <HTML.h>
#include <HTInit.h>
#include <LYGetFile.h>
#include <LYBookmark.h>
#include <GridText.h>
#include <LYCgi.h>
#include <LYStrings.h>
#include <LYLocal.h>
#include <LYLeaks.h>
#include <www_wait.h>
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 <index> 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, "<html>\n<head>\n<title>%s</title>\n</head>\n<body>\n",
gettext("Good Advice"));
PUTS(buf);
HTSprintf0(&buf, "<h1>%s</h1>\n", gettext("Good Advice"));
PUTS(buf);
HTSprintf0(&buf, "%s <a\n",
gettext("An excellent http server for VMS is available via"));
PUTS(buf);
HTSprintf0(&buf,
"href=\"http://www.ecr6.ohio-state.edu/www/doc/serverinfo.html\"\n");
PUTS(buf);
HTSprintf0(&buf, ">%s</a>.\n", gettext("this link"));
PUTS(buf);
HTSprintf0(&buf, "<p>%s\n",
gettext("It provides state of the art CGI script support.\n"));
PUTS(buf);
HTSprintf0(&buf, "</body>\n</html>\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 */