From a46a8824924c9264b876dbed3c6a8163f6ac1012 Mon Sep 17 00:00:00 2001
From: Gustav Behm <me@rootmos.io>
Date: Fri, 29 Mar 2024 07:05:56 +0100
Subject: [PATCH] Receive triggers

---
 c-impl/action.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)

diff --git a/c-impl/action.c b/c-impl/action.c
index 1d002ea..239de2c 100644
--- a/c-impl/action.c
+++ b/c-impl/action.c
@@ -1,8 +1,12 @@
+#define _GNU_SOURCE
+
 #include <poll.h>
 #include <signal.h>
 #include <sys/signalfd.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <sys/stat.h>
+#include <string.h>
 
 #define LIBR_IMPLEMENTATION
 #include "r.h"
@@ -147,6 +151,25 @@ const char* iso8601_timespec(const struct timespec* ts)
     return buf;
 }
 
+static void prepare_socket_path(const char* sp)
+{
+    struct stat st;
+    int r = stat(sp, &st);
+    if(r == 0) {
+        if((st.st_mode & S_IFMT) == S_IFSOCK) {
+            debug("socket already exists, trying to unlink: %s", sp);
+            r = unlink(sp);
+            CHECK(r, "unlink(%s)", sp);
+        } else {
+            failwith("socket path already exists (and is not a socket): %s", sp);
+        }
+    } else if(r == -1 && errno != ENOENT) {
+        CHECK(r, "stat(%s)", sp);
+    } else {
+        xdg_makedirs(dirname(strdupa(sp)));
+    }
+}
+
 int main(int argc, char* argv[])
 {
     struct options o;
@@ -197,6 +220,13 @@ int main(int argc, char* argv[])
         return 0;
     }
 
+    prepare_socket_path(socket_path);
+
+    int r = bind(fd, (const struct sockaddr*)&addr, sizeof(addr));
+    CHECK(r, "bind(%s)", socket_path);
+
+    set_blocking(fd, 0);
+
     struct state st = {
         .running = 1,
     };
@@ -205,6 +235,7 @@ int main(int argc, char* argv[])
 
     struct pollfd fds[] = {
         { .fd = signalfd_fd(&st), .events = POLLIN },
+        { .fd = fd, .events = POLLIN },
     };
 
     while(st.running) {
@@ -216,6 +247,23 @@ int main(int argc, char* argv[])
             fds[0].revents &= ~POLLIN;
         }
 
+        if(fds[1].revents & POLLIN) {
+            struct msg msg;
+            ssize_t s = recvfrom(fd, &msg, sizeof(msg), 0, NULL, NULL);
+            CHECK(s, "recvfrom(%s)", socket_path);
+
+            if(s != sizeof(msg)) {
+                failwith("unexpected partial recvfrom");
+            }
+
+            if(strncmp(msg.action, o.action, sizeof(msg.action)) == 0) {
+                info("triggered: %s (%s)", o.action, iso8601_timespec(&msg.timestamp));
+                st.running = 0;
+            }
+
+            fds[1].revents &= ~POLLIN;
+        }
+
         for(size_t i = 0; i < LENGTH(fds); i++) {
             if(fds[i].revents != 0) {
                 failwith("unhandled poll events: "
@@ -228,6 +276,10 @@ int main(int argc, char* argv[])
     debug("graceful shutdown");
     signalfd_deinit(&st);
 
+    r = close(fd); CHECK(r, "close");
+    r = unlink(socket_path);
+    CHECK(r, "unlink(%s)", socket_path);
+
 exit:
     xdg_free(xdg);
 
-- 
2.45.2