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#include "cache.h"

#include "tempfile.h"

#include "credential.h"

#include "unix-socket.h"

#include "parse-options.h"

static struct tempfile socket_file;

struct credential_cache_entry {

struct credential item;

unsigned long expiration;

};

static struct credential_cache_entry *entries;

static int entries_nr;

static int entries_alloc;

static void cache_credential(struct credential *c, int timeout)

{

struct credential_cache_entry *e;

ALLOC_GROW(entries, entries_nr + 1, entries_alloc);

e = &entries[entries_nr++];

/* take ownership of pointers */

memcpy(&e->item, c, sizeof(*c));

memset(c, 0, sizeof(*c));

e->expiration = time(NULL) + timeout;

}

static struct credential_cache_entry *lookup_credential(const struct credential *c)

{

int i;

for (i = 0; i < entries_nr; i++) {

struct credential *e = &entries[i].item;

if (credential_match(c, e))

return &entries[i];

}

return NULL;

}

static void remove_credential(const struct credential *c)

{

struct credential_cache_entry *e;

e = lookup_credential(c);

if (e)

e->expiration = 0;

}

static int check_expirations(void)

{

static unsigned long wait_for_entry_until;

int i = 0;

unsigned long now = time(NULL);

unsigned long next = (unsigned long)-1;

/*

* Initially give the client 30 seconds to actually contact us

* and store a credential before we decide there's no point in

* keeping the daemon around.

*/

if (!wait_for_entry_until)

wait_for_entry_until = now + 30;

while (i < entries_nr) {

if (entries[i].expiration <= now) {

entries_nr--;

credential_clear(&entries[i].item);

if (i != entries_nr)

memcpy(&entries[i], &entries[entries_nr], sizeof(*entries));

/*

* Stick around 30 seconds in case a new credential

* shows up (e.g., because we just removed a failed

* one, and we will soon get the correct one).

*/

wait_for_entry_until = now + 30;

}

else {

if (entries[i].expiration < next)

next = entries[i].expiration;

i++;

}

}

if (!entries_nr) {

if (wait_for_entry_until <= now)

return 0;

next = wait_for_entry_until;

}

return next - now;

}

static int read_request(FILE *fh, struct credential *c,

struct strbuf *action, int *timeout) {

static struct strbuf item = STRBUF_INIT;

const char *p;

strbuf_getline_lf(&item, fh);

if (!skip_prefix(item.buf, "action=", &p))

return error("client sent bogus action line: %s", item.buf);

strbuf_addstr(action, p);

strbuf_getline_lf(&item, fh);

if (!skip_prefix(item.buf, "timeout=", &p))

return error("client sent bogus timeout line: %s", item.buf);

*timeout = atoi(p);

if (credential_read(c, fh) < 0)

return -1;

return 0;

}

static void serve_one_client(FILE *in, FILE *out)

{

struct credential c = CREDENTIAL_INIT;

struct strbuf action = STRBUF_INIT;

int timeout = -1;

if (read_request(in, &c, &action, &timeout) < 0)

/* ignore error */ ;

else if (!strcmp(action.buf, "get")) {

struct credential_cache_entry *e = lookup_credential(&c);

if (e) {

fprintf(out, "username=%s\n", e->item.username);

fprintf(out, "password=%s\n", e->item.password);

}

}

else if (!strcmp(action.buf, "exit")) {

/*

* It's important that we clean up our socket first, and then

* signal the client only once we have finished the cleanup.

* Calling exit() directly does this, because we clean up in

* our atexit() handler, and then signal the client when our

* process actually ends, which closes the socket and gives

* them EOF.

*/

exit(0);

}

else if (!strcmp(action.buf, "erase"))

remove_credential(&c);

else if (!strcmp(action.buf, "store")) {

if (timeout < 0)

warning("cache client didn't specify a timeout");

else if (!c.username || !c.password)

warning("cache client gave us a partial credential");

else {

remove_credential(&c);

cache_credential(&c, timeout);

}

}

else

warning("cache client sent unknown action: %s", action.buf);

credential_clear(&c);

strbuf_release(&action);

}

static int serve_cache_loop(int fd)

{

struct pollfd pfd;

unsigned long wakeup;

wakeup = check_expirations();

if (!wakeup)

return 0;

pfd.fd = fd;

pfd.events = POLLIN;

if (poll(&pfd, 1, 1000 * wakeup) < 0) {

if (errno != EINTR)

die_errno("poll failed");

return 1;

}

if (pfd.revents & POLLIN) {

int client, client2;

FILE *in, *out;

client = accept(fd, NULL, NULL);

if (client < 0) {

warning_errno("accept failed");

return 1;

}

client2 = dup(client);

if (client2 < 0) {

warning_errno("dup failed");

close(client);

return 1;

}

in = xfdopen(client, "r");

out = xfdopen(client2, "w");

serve_one_client(in, out);

fclose(in);

fclose(out);

}

return 1;

}

static void serve_cache(const char *socket_path, int debug)

{

int fd;

fd = unix_stream_listen(socket_path);

if (fd < 0)

die_errno("unable to bind to '%s'", socket_path);

printf("ok\n");

fclose(stdout);

if (!debug) {

if (!freopen("/dev/null", "w", stderr))

die_errno("unable to point stderr to /dev/null");

}

while (serve_cache_loop(fd))

; /* nothing */

close(fd);

}

static const char permissions_advice[] = N_(

"The permissions on your socket directory are too loose; other\n"

"users may be able to read your cached credentials. Consider running:\n"

"\n"

" chmod 0700 %s");

static void init_socket_directory(const char *path)

{

struct stat st;

char *path_copy = xstrdup(path);

char *dir = dirname(path_copy);

if (!stat(dir, &st)) {

if (st.st_mode & 077)

die(_(permissions_advice), dir);

} else {

/*

* We must be sure to create the directory with the correct mode,

* not just chmod it after the fact; otherwise, there is a race

* condition in which somebody can chdir to it, sleep, then try to open

* our protected socket.

*/

if (safe_create_leading_directories_const(dir) < 0)

die_errno("unable to create directories for '%s'", dir);

if (mkdir(dir, 0700) < 0)

die_errno("unable to mkdir '%s'", dir);

}

if (chdir(dir))

/*

* We don't actually care what our cwd is; we chdir here just to

* be a friendly daemon and avoid tying up our original cwd.

* If this fails, it's OK to just continue without that benefit.

*/

;

free(path_copy);

}

int cmd_main(int argc, const char **argv)

{

const char *socket_path;

int ignore_sighup = 0;

static const char *usage[] = {

"git-credential-cache--daemon [opts] <socket_path>",

NULL

};

int debug = 0;

const struct option options[] = {

OPT_BOOL(0, "debug", &debug,

N_("print debugging messages to stderr")),

OPT_END()

};

git_config_get_bool("credentialcache.ignoresighup", &ignore_sighup);

argc = parse_options(argc, argv, NULL, options, usage, 0);

socket_path = argv[0];

if (!socket_path)

usage_with_options(usage, options);

if (!is_absolute_path(socket_path))

die("socket directory must be an absolute path");

init_socket_directory(socket_path);

register_tempfile(&socket_file, socket_path);

if (ignore_sighup)

signal(SIGHUP, SIG_IGN);

serve_cache(socket_path, debug);

delete_tempfile(&socket_file);

return 0;

}