Skip to content

Commit

Permalink
(net/a12/shmif) net_open to running remote appl
Browse files Browse the repository at this point in the history 
This pushes the previous commit to PoC state. It is now possible from an
arcan appl to connect to an a12-directory, browse its list of exposed
appls, download and run one.
  • Loading branch information
@letoram
letoram committed Jul 12, 2023
1 parent 37b813a commit a8cbf3e
Show file tree
Hide file tree
Showing 5 changed files with 354 additions and 89 deletions.
182 changes: 127 additions & 55 deletions src/a12/net/directory.c
View file
Expand Up @@ -178,13 +178,13 @@ void anet_directory_ioloop
void (*on_userfd)(struct a12_state* S, void*))
{
int errmask = POLLERR | POLLNVAL | POLLHUP;
struct pollfd fds[2] =
struct pollfd fds[3] =
{
{.fd = usrfd, .events = POLLIN | errmask},
{.fd = fdin, .events = POLLIN | errmask},
{.fd = fdout, .events = POLLOUT | errmask}
{.fd = -fdout, .events = POLLOUT | errmask}
};

size_t n_fd = 1;
uint8_t inbuf[9000];
uint8_t* outbuf = NULL;
uint64_t ts = 0;
Expand All @@ -193,25 +193,28 @@ void anet_directory_ioloop
fcntl(fdout, F_SETFD, FD_CLOEXEC);

size_t outbuf_sz = a12_flush(S, &outbuf, A12_FLUSH_ALL);

if (outbuf_sz)
n_fd++;
fds[2].fd = fdout;

/* regular simple processing loop, wait for DIRECTORY-LIST command */
while (a12_ok(S) && -1 != poll(fds, n_fd, -1)){
if (
(fds[0].revents & errmask) ||
(n_fd == 2 && fds[1].revents & errmask))
break;
while (a12_ok(S) && -1 != poll(fds, 3, -1)){
if ((fds[0].revents | fds[1].revents | fds[2].revents) & errmask)
break;

if (n_fd == 2 && (fds[1].revents & POLLOUT) && outbuf_sz){
if (fds[0].revents & POLLIN){
on_userfd(S, tag);
}

if ((fds[2].revents & POLLOUT) && outbuf_sz){
ssize_t nw = write(fdout, outbuf, outbuf_sz);
if (nw > 0){
outbuf += nw;
outbuf_sz -= nw;
}
}

if (fds[0].revents & POLLIN){
if (fds[1].revents & POLLIN){
ssize_t nr = recv(fdin, inbuf, 9000, 0);
if (-1 == nr && errno != EAGAIN && errno != EWOULDBLOCK && errno != EINTR){
a12int_trace(A12_TRACE_DIRECTORY, "shutdown:reason=rw_error");
Expand Down Expand Up @@ -242,9 +245,9 @@ void anet_directory_ioloop
}
}

n_fd = outbuf_sz > 0 ? 2 : 1;
fds[0].revents = fds[1].revents = fds[2].revents = 0;
fds[2].fd = outbuf_sz ? fdout : -1;
}

}

/* this will just keep / cache the built .tars in memory, the startup times
Expand Down Expand Up @@ -323,47 +326,59 @@ static bool ensure_appldir(const char* name, int basedir)
return true;
}

/* assumes that cwd points to our scratch folder for extracted appls */
static bool handover_exec(struct a12_state* S, const char* name,
FILE* state_in, struct anet_dircl_opts* opts, int* state, size_t* state_sz)
{
char buf[strlen(name) + sizeof("./")];
snprintf(buf, sizeof(buf), "./%s", name);
*state_sz = 0;
struct default_meta {
const char* bin;
char* key;
char* val;
};

const char* binary = "arcan";
static void* alloc_cpath(struct a12_state* S, struct directory_meta* dir)
{
const char* cpath = getenv("ARCAN_CONNPATH");
struct default_meta* res = malloc(sizeof(struct default_meta));
*res = (struct default_meta){.bin = "arcan"};

if (!cpath)
return NULL;

/* this repeats the lookup code found in arcan_shmif_control.c */
size_t maxlen = sizeof((struct sockaddr_un){0}.sun_path);
char cpath_full[maxlen];

/* to avoid the connpaths duelling with an outer arcan, or the light security
* issue of the loaded appl being able to namespace-collide/ override - first
* make sure to resolve the current connpath to absolute - then set the XDG_
* runtime dir to our scratch folder. */
if (cpath){
if (cpath[0] != '/'){
char* basedir = getenv("XDG_RUNTIME_DIR");
if (snprintf(cpath_full, maxlen, "%s/%s%s",
basedir ? basedir : getenv("HOME"),
basedir ? "" : ".", cpath) >= maxlen){
fprintf(stderr,
"Resolved path too long, cannot handover to arcan(_lwa)\n");
return false;
*state = -1;
}
if ((cpath)[0] != '/'){
char* basedir = getenv("XDG_RUNTIME_DIR");
if (snprintf(cpath_full, maxlen, "%s/%s%s",
basedir ? basedir : getenv("HOME"),
basedir ? "" : ".", cpath) >= maxlen){
free(res);
fprintf(stderr,
"Resolved path too long, cannot handover to arcan(_lwa)\n");
return NULL;
}

binary = "arcan_lwa";
}

res->key = strdup("ARCAN_CONNPATH"),
res->val = strdup(cpath_full);
res->bin = "arcan_lwa";

return res;
}

static pid_t exec_cpath(struct a12_state* S,
struct directory_meta* dir, const char* name, void* tag, int* inf, int* outf)
{
struct default_meta* ctx = tag;

char buf[strlen(name) + sizeof("./")];
snprintf(buf, sizeof(buf), "./%s", name);

char logfd_str[16];
int pstdin[2], pstdout[2];

if (-1 == pipe(pstdin) || -1 == pipe(pstdout)){
fprintf(stderr,
"Couldn't setup control pipe in arcan handover\n");
return false;
*state = -1;
return 0;
}

snprintf(logfd_str, 16, "LOGFD:%d", pstdout[1]);
Expand Down Expand Up @@ -393,8 +408,9 @@ static bool handover_exec(struct a12_state* S, const char* name,
pid_t pid = fork();
if (pid == 0){
/* remap control into STDIN */
if (cpath)
setenv("ARCAN_CONNPATH", cpath_full, 1);
if (ctx->key)
setenv(ctx->key, ctx->val, 1);

setenv("XDG_RUNTIME_DIR", "./", 1);
dup2(pstdin[0], STDIN_FILENO);
close(pstdin[0]);
Expand All @@ -404,19 +420,69 @@ static bool handover_exec(struct a12_state* S, const char* name,
close(STDOUT_FILENO);
open("/dev/null", O_WRONLY);
open("/dev/null", O_WRONLY);
execvp(binary, argv);
execvp(ctx->bin, argv);
exit(EXIT_FAILURE);
}

close(pstdin[0]);
close(pstdout[1]);

*inf = pstdin[1];
*outf = pstdout[0];
free(ctx->key);
free(ctx->val);

return pid;
}

/*
* This entire function is protoype- quality and mainly for figuring out the
* interface / path between arcan (lwa), appl, arcan-net and a12.
*
* Its main purpose is to setup the env for arcan to either run the appl as a
* normal display server, within an existing arcan one or from within another
* desktop.
*
* It also launches / runs and blocks into a 'monitoring' mode used for setting
* the initial state, capture crash dumps and snapshot / backup state.
*
* It is likely that the stdin/stdout pipe/monitor interface would be better
* served by another shmif/shmif server connection, but right now it is just
* plaintext.
*/
static bool handover_exec(struct a12_state* S, const char* name,
FILE* state_in, struct directory_meta* dir, int* state, size_t* state_sz)
{
struct anet_dircl_opts* opts = dir->clopt;

void* tag = opts->allocator(S, dir);
if (!tag){
*state = -1;
return false;
}

/* ongoing refactor to break this out entirely */
int inf = -1;
int outf = -1;
*state_sz = 0;

pid_t pid = opts->executor(S, dir, name, tag, &inf, &outf);
if (pid <= 0){
free(tag);
fprintf(stderr, "executor-failed");
*state = -1;
return false;
}

if (pid == -1){
clean_appldir(name, opts->basedir);
fprintf(stderr, "Couldn't spawn child process");
*state = -1;
return false;
}
close(pstdin[0]);
close(pstdout[1]);

FILE* pfin = fdopen(pstdin[1], "w");
FILE* pfout = fdopen(pstdout[0], "r");
FILE* pfin = fdopen(inf, "w");
FILE* pfout = fdopen(outf, "r");
setlinebuf(pfin);
setlinebuf(pfout);

Expand Down Expand Up @@ -452,9 +518,8 @@ static bool handover_exec(struct a12_state* S, const char* name,
int pret = 0;
char* out = NULL;
char filename[] = "statetemp-XXXXXX";
int state_fd = -1;

if (-1 == (state_fd = mkstemp(filename))){
int state_fd = mkstemp(filename);
if (-1 == state_fd){
fprintf(stderr, "Couldn't create temp-store, state transfer disabled\n");
}
else
Expand Down Expand Up @@ -629,8 +694,9 @@ static void mark_xfer_complete(

int state_out = -1;
size_t state_sz = 0;

bool exec_res = handover_exec(S,
cbt->clopt->applname, state_in, cbt->clopt, &state_out, &state_sz);
cbt->clopt->applname, state_in, cbt, &state_out, &state_sz);

if (state_in)
fclose(state_in);
Expand Down Expand Up @@ -671,7 +737,7 @@ static void mark_xfer_complete(
g_shutdown = true;
}

static struct a12_bhandler_res cl_bevent(
struct a12_bhandler_res anet_directory_cl_bhandler(
struct a12_state* S, struct a12_bhandler_meta M, void* tag)
{
struct directory_meta* cbt = tag;
Expand Down Expand Up @@ -764,7 +830,7 @@ static bool cl_got_dir(struct a12_state* S, struct appl_meta* M, void* tag)

while (M){
/* use identifier to request binary */
if (cbt->clopt->applname){
if (cbt->clopt->applname[0]){
if (strcasecmp(M->applname, cbt->clopt->applname) == 0){
struct arcan_event ev =
{
Expand All @@ -780,16 +846,17 @@ static bool cl_got_dir(struct a12_state* S, struct appl_meta* M, void* tag)
a12_channel_enqueue(S, &ev);

/* and register our store+launch handler */
a12_set_bhandler(S, cl_bevent, tag);
a12_set_bhandler(S, anet_directory_cl_bhandler, tag);
return true;
}
}
else
printf("name=%s\n", M->applname);

M = M->next;
}

if (cbt->clopt->applname){
if (cbt->clopt->applname[0]){
fprintf(stderr, "appl:%s not found\n", cbt->clopt->applname);
return false;
}
Expand All @@ -809,6 +876,11 @@ void anet_directory_cl(
.state_in = -1
};

if (!opts.allocator || !opts.executor){
opts.allocator = alloc_cpath;
opts.executor = exec_cpath;
}

sigaction(SIGPIPE,&(struct sigaction){.sa_handler = SIG_IGN}, 0);

/* always request dirlist so we can resolve applname against the server-local
Expand Down
10 changes: 9 additions & 1 deletion src/a12/net/directory.h
View file
Expand Up @@ -25,14 +25,19 @@ struct anet_dirsrv_opts {
*
* Which again ties into some need to be able to inject events into shmif
*/
struct directory_meta;
struct anet_dircl_opts {
int basedir;
const char* applname;
char applname[16];
bool die_on_list;
bool reload;
bool block_state;
bool block_log;
bool keep_appl;

void* (*allocator)(struct a12_state*, struct directory_meta*);
pid_t (*executor)(struct a12_state*,
struct directory_meta*, const char*, void* tag, int* inf, int* outf);
};

struct directory_meta {
Expand All @@ -53,6 +58,9 @@ void anet_directory_srv(
void anet_directory_cl(
struct a12_state* S, struct anet_dircl_opts opts, int fdin, int fdout);

struct a12_bhandler_res anet_directory_cl_bhandler(
struct a12_state* S, struct a12_bhandler_meta M, void* tag);

/*
* handle a12 on fdin/fdout,
* multiplex and trigger on incoming for usrfd_mask (typically shmif)
Expand Down
5 changes: 3 additions & 2 deletions src/a12/net/net.c
View file
Expand Up @@ -1082,11 +1082,12 @@ int main(int argc, char** argv)
* sinks and other directories. */
int rc = 0;
if (a12_remote_mode(cl.state) == ROLE_DIR){
global.dircl.applname = global.reqname;
if (global.reqname)
snprintf(global.dircl.applname, 16, "%s", global.reqname);
global.dircl.die_on_list;
global.dircl.basedir = global.directory;
if (argi <= argc - 1){
global.dircl.applname = argv[argi];
snprintf(global.dircl.applname, 16, "%s", argv[argi]);
}

anet_directory_cl(cl.state, global.dircl, cl.fd, cl.fd);
Expand Down

0 comments on commit a8cbf3e

Please sign in to comment.