initial commit

prezzyd.c

@@ -0,0 +1,258 @@
+/*
+ * prezzyd
+ * Copyright (c) 2024 Jeremy Baxter.
+ */
+
+#define _PREZZYD_C_
+#define _DEFAULT_SOURCE
+
+#ifndef BUILD_DATE
+#define BUILD_DATE "1970-01-01"
+#endif
+
+#include <err.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "prezzyipc.h"
+#include "discord_rpc.h"
+
+void
+connectHandler(const DiscordUser *user)
+{
+	warnx("established connection to Discord (%s/%s)",
+		  user->username, user->userId);
+}
+
+void
+disconnectHandler(int code, const char *message)
+{
+	warnx("disconnected from client (%d: %s)", code, message);
+}
+
+void
+errorHandler(int code, const char *message)
+{
+	errx(1, "rpc error %d: %s", code, message);
+}
+
+int
+canReadFrom(int fd)
+{
+	struct pollfd *p;
+	int ret;
+
+	p = malloc(sizeof(struct pollfd));
+	p->fd = fd;
+	p->events = POLLIN;
+
+	if (poll(p, 1, 5000) == -1)
+		err(1, "failed to poll client");
+
+	ret = p->revents & POLLIN;
+	free(p);
+	return ret;
+}
+
+int
+ipcClose(int fd, byte code, const char *message)
+{
+	write(fd, (char []){code}, 1);
+	write(fd, message, strlen(message));
+	if (close(fd) == -1)
+		err(1, "failed to close IPC connection");
+
+	return code;
+}
+
+void
+ipcSucceed(int fd)
+{
+	ipcClose(fd, 0, "OK");
+}
+
+int
+makeIpcServer(const char *bindPath, int backlog)
+{
+	struct sockaddr_un addr;
+	int fd;
+
+	if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1)
+		err(1, "failed to create IPC socket");
+
+	if (remove(bindPath) == -1) {
+		if (errno != ENOENT)
+			err(1, "could not remove %s", bindPath);
+	}
+
+	memset(&addr, 0, sizeof(struct sockaddr_un));
+	addr.sun_family = AF_UNIX;
+	strbcpy(addr.sun_path, bindPath, sizeof(addr.sun_path) - 1);
+
+	if (bind(fd, (struct sockaddr *) &addr, sizeof(struct sockaddr_un)) == -1)
+		err(1, "failed to bind to %s", bindPath);
+	if (listen(fd, backlog) == -1)
+		err(1, "failed to listen on IPC socket %s", bindPath);
+
+	if (fcntl(fd, F_SETFL, fcntl(fd, F_GETFL, 0) | O_NONBLOCK) == -1)
+		err(1, "failed to create non-blocking IPC socket");
+
+	return fd;
+}
+
+int
+main(int argc, char **argv)
+{
+	void *propertyMapping[PREZZY_PROPERTY_MAX];
+	DiscordRichPresence presence;
+	DiscordEventHandlers handlers;
+	const char *clientId;
+	int ch, sd;
+
+	while ((ch = getopt(argc, argv, "V")) != -1) {
+		switch (ch) {
+		case 'V':
+			printf("prezzyd version 0.1 built on " BUILD_DATE "\n");
+			return 0;
+			break;
+		}
+	}
+
+	if (argc - optind != 1) {
+		fputs("usage: prezzyd [-V] client-id\n", stderr);
+		return 1;
+	}
+
+	clientId = argv[optind];
+
+	memset(&presence, 0, sizeof(DiscordRichPresence));
+	memset(&handlers, 0, sizeof(DiscordEventHandlers));
+	handlers.ready = connectHandler;
+	handlers.disconnected = disconnectHandler;
+	handlers.errored = errorHandler;
+
+	Discord_Initialize(clientId, &handlers, 1, NULL);
+
+	propertyMapping[PREZZY_STATE]           = &presence.state;
+	propertyMapping[PREZZY_DETAILS]         = &presence.details;
+	propertyMapping[PREZZY_LARGE_IMAGE]     = &presence.largeImageKey;
+	propertyMapping[PREZZY_LARGE_TOOLTIP]   = &presence.largeImageText;
+	propertyMapping[PREZZY_ICON]            = &presence.smallImageKey;
+	propertyMapping[PREZZY_ICON_TOOLTIP]    = &presence.smallImageText;
+	propertyMapping[PREZZY_PARTY_SIZE]      = &presence.partySize;
+	propertyMapping[PREZZY_PARTY_LIMIT]     = &presence.partyMax;
+	propertyMapping[PREZZY_TIMESTAMP_START] = &presence.startTimestamp;
+	propertyMapping[PREZZY_TIMESTAMP_END]   = &presence.endTimestamp;
+
+	/* start ipc server */
+	sd = makeIpcServer(PREZZY_SOCK, 8);
+
+	for (;;) {
+		PrezzyIpcPacket **packets;
+		char buffer[PREZZY_PACKET_MAX];
+		ssize_t sz;
+		int client, i, packetCount;
+		char ch;
+
+		packets = NULL;
+		packetCount = 0;
+		client = accept(sd, NULL, NULL);
+
+		if (client == -1) {
+			switch (errno) {
+			case EWOULDBLOCK:
+				goto update;
+			default:
+				err(1, "failed to accept incoming IPC connection");
+				break;
+			}
+		}
+
+		/*
+		 * IPC error codes:
+		 *   1: error during initial read
+		 *   2: bad request format
+		 */
+
+		if (!canReadFrom(client))
+			ipcClose(client, 1, "Timed out");
+
+		for (i = 0; (sz = read(client, &ch, 1)) > 0; i++) {
+			if (i == PREZZY_PACKET_MAX) {
+				ipcClose(client, 0, "OK (truncated)");
+				buffer[i - 1] = '\0';
+				break;
+			}
+
+			switch (ch) {
+			case '\n':
+			case '\0':
+				/* end current packet */
+				if (i + 1 < 2 && /* are we before the payload? */
+					/* accept null bytes after newlines */
+					!(ch == '\0' && i == 0)) { 
+					ipcClose(client, 2, "Request missing payload");
+					goto update;
+				}
+				if (buffer[0] < 0 || buffer[0] >= PREZZY_PROPERTY_MAX) {
+					ipcClose(client, 2, "Invalid property byte");
+					goto update;
+				}
+				buffer[i] = '\0';
+
+				packetCount++;
+				packets = realloc(packets, packetCount *
+										   sizeof(PrezzyIpcPacket *));
+				packets[packetCount - 1] = makeIpcPacket(buffer);
+
+				if (ch == '\0') {
+					ipcSucceed(client);
+					goto process;
+				}
+				/* '\n'; more requests later */
+				i = -1;
+				continue;
+			default:
+				buffer[i] = ch;
+				break;
+			}
+		}
+
+		if (sz == -1)
+			err(1, "failed to read from IPC client");
+
+	process:
+		for (i = 0; i < packetCount; i++) {
+			size_t len;
+
+			if (packets[i]->type == PLT_STRING) {
+				len = strlen(packets[i]->pString) + 1;
+				*(char **)propertyMapping[packets[i]->property] =
+					malloc(len * sizeof(char));
+				strlcpy(*(char **)propertyMapping[packets[i]->property],
+						packets[i]->pString, len);
+			} else {
+				if (packets[i]->type == PLT_INT64) {
+					*(int64_t *)propertyMapping[packets[i]->property] =
+						packets[i]->pInteger;
+				} else {
+					*(int *)propertyMapping[packets[i]->property] =
+						squashLong(packets[i]->pInteger);
+				}
+			}
+		}
+
+	update:
+		Discord_UpdatePresence(&presence);
+		Discord_RunCallbacks();
+		usleep(64000);
+	}
+
+	Discord_Shutdown();
+
+	return 0;	
+}