/*
* Forking is a relatively cheap way to create a new client. The new
* client record shares the IO descriptors. To avoid interference, we
* limit children to only produce output by closing the input-side.
*
* If the father itself is a temporary client, let the new child depend
* on the grandfather.
*/
Client
MCforkClient(Client father)
{
Client son = NULL;
if (father == NULL)
return NULL;
if (father->father != NULL)
father = father->father;
if ((son = MCinitClient(father->user, father->fdin, father->fdout))) {
son->fdin = NULL;
son->fdout = father->fdout;
son->bak = NULL;
son->yycur = 0;
son->father = father;
son->scenario = father->scenario;
if (son->prompt)
GDKfree(son->prompt);
son->prompt = GDKstrdup(father->prompt);
son->promptlength = strlen(father->prompt);
/* reuse the scopes wherever possible */
if (son->nspace == 0)
son->nspace = newModule(NULL, putName("child", 5));
son->nspace->outer = father->nspace->outer;
}
return son;
}
/*
* The MonetDB server uses a startup script to boot the system.
* This script is an ordinary MAL program, but will mostly
* consist of include statements to load modules of general interest.
* The startup script is run as user Admin.
*/
int
malBootstrap(void)
{
Client c;
str msg, bootfile = "mal_init", s;
c = MCinitClient((oid) 0, 0, 0);
assert(c != NULL);
c->nspace = newModule(NULL, putName("user", 4));
initLibraries();
if ( (msg = defaultScenario(c)) ) {
GDKfree(msg);
GDKerror("Failed to initialise default scenario");
return 0;
}
MSinitClientPrg(c, "user", "main");
(void) MCinitClientThread(c);
s = malInclude(c, bootfile, 0);
if (s != NULL) {
mnstr_printf(GDKout, "!%s\n", s);
GDKfree(s);
return 0;
}
pushEndInstruction(c->curprg->def);
chkProgram(c->fdout, c->nspace, c->curprg->def);
if (c->curprg->def->errors)
showErrors(c);
s = MALengine(c);
if (s)
GDKfree(s);
return 1;
}
/*
* Forking is a relatively cheap way to create a new client. The new
* client record shares the IO descriptors. To avoid interference, we
* limit children to only produce output by closing the input-side.
*
* If the father itself is a temporary client, let the new child depend
* on the grandfather.
*/
Client
MCforkClient(Client father)
{
Client son = NULL;
str prompt;
if (father == NULL)
return NULL;
if (father->father != NULL)
father = father->father;
if((prompt = GDKstrdup(father->prompt)) == NULL)
return NULL;
if ((son = MCinitClient(father->user, father->fdin, father->fdout))) {
son->fdin = NULL;
son->fdout = father->fdout;
son->bak = NULL;
son->yycur = 0;
son->father = father;
son->scenario = father->scenario;
if (son->prompt)
GDKfree(son->prompt);
son->prompt = prompt;
son->promptlength = strlen(prompt);
/* reuse the scopes wherever possible */
if (son->usermodule == 0) {
son->usermodule = userModule();
if(son->usermodule == 0) {
MCcloseClient(son);
return NULL;
}
}
} else {
GDKfree(prompt);
}
return son;
}
void
MSscheduleClient(str command, str challenge, bstream *fin, stream *fout)
{
char *user = command, *algo = NULL, *passwd = NULL, *lang = NULL;
char *database = NULL, *s, *dbname;
Client c;
/* decode BIG/LIT:user:{cypher}passwordchal:lang:database: line */
/* byte order */
s = strchr(user, ':');
if (s) {
*s = 0;
mnstr_set_byteorder(fin->s, strcmp(user, "BIG") == 0);
user = s + 1;
} else {
mnstr_printf(fout, "!incomplete challenge '%s'\n", user);
exit_streams(fin, fout);
GDKfree(command);
return;
}
/* passwd */
s = strchr(user, ':');
if (s) {
*s = 0;
passwd = s + 1;
/* decode algorithm, i.e. {plain}mypasswordchallenge */
if (*passwd != '{') {
mnstr_printf(fout, "!invalid password entry\n");
exit_streams(fin, fout);
GDKfree(command);
return;
}
algo = passwd + 1;
s = strchr(algo, '}');
if (!s) {
mnstr_printf(fout, "!invalid password entry\n");
exit_streams(fin, fout);
GDKfree(command);
return;
}
*s = 0;
passwd = s + 1;
} else {
mnstr_printf(fout, "!incomplete challenge '%s'\n", user);
exit_streams(fin, fout);
GDKfree(command);
return;
}
/* lang */
s = strchr(passwd, ':');
if (s) {
*s = 0;
lang = s + 1;
} else {
mnstr_printf(fout, "!incomplete challenge, missing language\n");
exit_streams(fin, fout);
GDKfree(command);
return;
}
/* database */
s = strchr(lang, ':');
if (s) {
*s = 0;
database = s + 1;
/* we can have stuff following, make it void */
s = strchr(database, ':');
if (s)
*s = 0;
}
dbname = GDKgetenv("gdk_dbname");
if (database != NULL && database[0] != '\0' &&
strcmp(database, dbname) != 0)
{
mnstr_printf(fout, "!request for database '%s', "
"but this is database '%s', "
"did you mean to connect to monetdbd instead?\n",
database, dbname);
/* flush the error to the client, and abort further execution */
exit_streams(fin, fout);
GDKfree(command);
return;
} else {
str err;
oid uid;
sabdb *stats = NULL;
Client root = &mal_clients[0];
/* access control: verify the credentials supplied by the user,
* no need to check for database stuff, because that is done per
* database itself (one gets a redirect) */
err = AUTHcheckCredentials(&uid, root, &user, &passwd, &challenge, &algo);
if (err != MAL_SUCCEED) {
mnstr_printf(fout, "!%s\n", err);
exit_streams(fin, fout);
GDKfree(err);
GDKfree(command);
return;
}
err = SABAOTHgetMyStatus(&stats);
if (err != MAL_SUCCEED) {
/* this is kind of awful, but we need to get rid of this
* message */
fprintf(stderr, "!SABAOTHgetMyStatus: %s\n", err);
if (err != M5OutOfMemory)
GDKfree(err);
mnstr_printf(fout, "!internal server error, "
"please try again later\n");
exit_streams(fin, fout);
GDKfree(command);
return;
}
if (stats->locked == 1) {
if (uid == 0) {
mnstr_printf(fout, "#server is running in "
"maintenance mode\n");
} else {
mnstr_printf(fout, "!server is running in "
"maintenance mode, please try again later\n");
exit_streams(fin, fout);
SABAOTHfreeStatus(&stats);
GDKfree(command);
return;
}
}
SABAOTHfreeStatus(&stats);
c = MCinitClient(uid, fin, fout);
if (c == NULL) {
if ( MCshutdowninprogress())
mnstr_printf(fout, "!system shutdown in progress, please try again later\n");
else
mnstr_printf(fout, "!maximum concurrent client limit reached "
"(%d), please try again later\n", MAL_MAXCLIENTS);
exit_streams(fin, fout);
GDKfree(command);
return;
}
/* move this back !! */
if (c->nspace == 0) {
c->nspace = newModule(NULL, putName("user", 4));
c->nspace->outer = mal_clients[0].nspace->outer;
}
if ((s = setScenario(c, lang)) != NULL) {
mnstr_printf(c->fdout, "!%s\n", s);
mnstr_flush(c->fdout);
GDKfree(s);
c->mode = FINISHCLIENT;
}
if (!GDKgetenv_isyes(mal_enableflag) &&
(strncasecmp("sql", lang, 3) != 0 && uid != 0)) {
mnstr_printf(fout, "!only the 'monetdb' user can use non-sql languages. "
"run mserver5 with --set %s=yes to change this.\n", mal_enableflag);
exit_streams(fin, fout);
GDKfree(command);
return;
}
}
MSinitClientPrg(c, "user", "main");
GDKfree(command);
/* NOTE ABOUT STARTING NEW THREADS
* At this point we have conducted experiments (Jun 2012) with
* reusing threads. The implementation used was a lockless array of
* semaphores to wake up threads to do work. Experimentation on
* Linux, Solaris and Darwin showed no significant improvements, in
* most cases no improvements at all. Hence the following
* conclusion: thread reuse doesn't save up on the costs of just
* forking new threads. Since the latter means no difficulties of
* properly maintaining a pool of threads and picking the workers
* out of them, it is favourable just to start new threads on
* demand. */
/* fork a new thread to handle this client */
mnstr_settimeout(c->fdin->s, 50, GDKexiting);
MSserveClient(c);
}
