Begin implementation of radharc-ipc

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 153 insertions, 1 deletions

diff --git a/radharc.c b/radharc.c
index ac53ca3..e48dc6f 100644
--- a/radharc.c
+++ b/radharc.c
@@ -1,8 +1,11 @@
 /* See LICENSE file for copyright and license details. */
 #include "cg-base.h"
 
+#include <sys/socket.h>
 #include <sys/timerfd.h>
+#include <sys/un.h>
 #include <errno.h>
+#include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -13,6 +16,7 @@
 
 
 #define IF_LINEARISING(...) do { if (linearise) { __VA_ARGS__; } } while (0)
+#define SOCKLEN (socklen_t)sizeof
 
 
 /**
@@ -23,7 +27,7 @@ const int64_t default_priority = (int64_t)7 << 61;
 /**
  * The default class for the program
  */
-char default_class[] = "radharc::radharc::standard";
+char default_class[] = PACKAGE_NAME"::"COMMAND_NAME"::standard";
 
 /**
  * Class suffixes
@@ -110,6 +114,16 @@ static int print_temperature = 0;
  */
 static int linearise = 1;
 
+/**
+ * The abstract address the socket shall have,
+ * if empty, no socket will be created, if
+ * `NULL` a default address derived from the
+ * process ID and the filter class will be used.
+ * If "-", standard input will be used and should
+ * already be bound.
+ */
+static const char *sockname = NULL;
+
 
 /**
  * Set to 1 by `handle_args` if the used arguments
@@ -228,6 +242,22 @@ vendor_options(char *arg)
 				linearise = 0;
 			else
 				goto invalid_value;
+		} else if (!strcmp(arg, "socket")) {
+			if (next) {
+				next[-1] = ',';
+				next = NULL;
+			}
+			if (!value)
+				goto missing_value;
+			else if (!*value)
+				goto invalid_value;
+			else
+				sockname = value;
+		} else if (!strcmp(arg, "no-socket")) {
+			if (value)
+				goto unexpected_value;
+			else
+				sockname = "";
 		} else {
 			fprintf(stderr, "%s: invalid -W option: %s\n", argv0, arg);
 			exit(1);
@@ -236,6 +266,10 @@ vendor_options(char *arg)
 
 	return;
 
+unexpected_value:
+	fprintf(stderr, "%s: -W option '%s' has an associated value, but must not\n", argv0, arg);
+	exit(1);
+
 missing_value:
 	fprintf(stderr, "%s: invalid -W option '%s' is missing associated value\n", argv0, arg);
 	exit(1);
@@ -651,6 +685,41 @@ sigusr2_handler(int sig)
 
 
 /**
+ * Called to pull all messages from the IPC socket
+ *
+ * @param  sock  The socket's file descriptor, or -1 if there is none
+ */
+static void
+read_socket(int sock)
+{
+	char buffer[64];
+	ssize_t r;
+
+	if (sock < 0)
+		return;
+
+	for (;;) {
+		r = recv(sock, buffer, sizeof(buffer), MSG_DONTWAIT | MSG_TRUNC);
+		if (r < 0) {
+			if (errno == EAGAIN)
+				break;
+			if (errno == EINTR || errno == ECONNREFUSED)
+				continue;
+			perror(argv0);
+			exit(1);
+		}
+
+		if (!r || (size_t)r > sizeof(buffer)) {
+			fprintf(stderr, "%s: invalid length of received message: %zi\n", argv0, r);
+			continue;
+		}
+
+		/* TODO parse message */
+	}
+}
+
+
+/**
  * The main function for the program-specific code
  * 
  * @return  0: Success
@@ -674,6 +743,10 @@ start(void)
 	size_t fade_cs;
 	double cs;
 	sigset_t empty_sigset;
+	int sock = -1;
+	struct sockaddr_un addr;
+	size_t addrlen;
+	struct f_owner_ex owner;
 
 	sigemptyset(&empty_sigset);
 
@@ -716,6 +789,78 @@ start(void)
 	if (xflag)
 		return set_ramps(1, 1, 1);
 
+	memset(&addr, 0, sizeof(addr));
+	addrlen = offsetof(struct sockaddr_un, sun_path);
+	addr.sun_family = AF_UNIX;
+	if (!sockname) {
+		size_t len = strlen(crtc_updates[0].filter.class);
+		size_t off = 1U;
+		off += (size_t)sprintf(&addr.sun_path[off], "/proc/%ju/", (uintmax_t)getpid());
+		if (len > sizeof(addr.sun_path) - 1U) {
+			fprintf(stderr, "%s: socket name is too long; you can may -R shorter,"
+				"select a name with -W socket, or use -W no-socket to skip the socket\n", argv0);
+			return -3;
+		}
+		memcpy(&addr.sun_path[off], crtc_updates[0].filter.class, len);
+		addrlen += off + len;
+		goto create_socket;
+	} else if (!strcmp(sockname, "-")) {
+		int opt;
+		socklen_t len = SOCKLEN(opt);
+		sock = STDIN_FILENO;
+		if (getsockopt(sock, SOL_SOCKET, SO_DOMAIN, &opt, &len)) {
+			if (errno != ENOTSOCK)
+				return -1;
+			fprintf(stderr, "%s: -W socket=- used but standard input is not socket\n", argv0);
+			return -3;
+		}
+		if (opt != PF_UNIX) {
+			fprintf(stderr, "%s: -W socket=- used but standard input is not a unix socket\n", argv0);
+			return -3;
+		}
+		if (getsockopt(sock, SOL_SOCKET, SO_TYPE, &opt, &len))
+			return -1;
+		if (opt != SOCK_DGRAM) {
+			fprintf(stderr, "%s: -W socket=- used but standard input is not a datagram socket\n", argv0);
+			return -3;
+		}
+		len = SOCKLEN(addr);
+		if (getsockname(sock, &addr, &len))
+			return -1;
+		if (len <= offsetof(struct sockaddr_un, sun_path) || addr.sun_family != AF_UNIX) {
+			fprintf(stderr, "%s: -W socket=- used but standard input is not bound to a unix socket address\n", argv0);
+			return -3;
+		}
+		if (len > SOCKLEN(addr)) {
+			fprintf(stderr, "%s: stanard input is bound to an overly long address\n", argv0);
+			return -3;
+		}
+		addrlen = len;
+	} else if (*sockname) {
+		size_t len = strlen(sockname);
+		if (len > sizeof(addr.sun_path) - 1U) {
+			fprintf(stderr, "%s: selected socket name is too long\n", argv0);
+			return -3;
+		}
+		memcpy(&addr.sun_path[1U], sockname, len);
+		addrlen += len + 1U;
+	create_socket:
+		sock = socket(PF_UNIX, SOCK_DGRAM, 0);
+		if (sock < 0)
+			return -1;
+		if (bind(sock, (void *)&addr, (socklen_t)addrlen))
+			return -1;
+	} else {
+		goto no_socket;
+	}
+	if (fcntl(sock, F_SETSIG, SIGIO) < 0)
+		return -1;
+	owner.type = F_OWNER_TID;
+	owner.pid = gettid();
+	if (fcntl(sock, F_SETOWN_EX, &owner) < 0)
+		return -1;
+no_socket:
+
 	if ((r = make_slaves()) < 0)
 		return r;
 
@@ -740,6 +885,7 @@ fade_in:
 		original_temperature = 6500;
 	}
 	for (i = 0; i < fade_cs;) {
+		read_socket(sock);
 		if (sigint_received) {
 			goto reverse_fade_in;
 		} else if (sigusr2_received) {
@@ -778,6 +924,7 @@ skip_fade_in:
 
 faded_in:
 	for (;;) {
+		read_socket(sock);
 		if (sigint_received) {
 			goto fade_out;
 		} else if (sighup_received) {
@@ -806,6 +953,7 @@ faded_in:
 		sleep_timeout.tv_nsec = 0;
 		while ((errno = clock_nanosleep(CLOCK_BOOTTIME, 0, &sleep_timeout, &sleep_timeout))) {
 			if (errno == EINTR) {
+				read_socket(sock);
 				if (sigint_received || sighup_received || sigusr1_received || sigusr2_received)
 					break;
 				continue;
@@ -829,6 +977,7 @@ fade_out:
 fade_out_have_timer:
 	original_temperature = current_temperature;
 	for (i = 0; i < fade_cs;) {
+		read_socket(sock);
 		if (sigint_received > 1 || sigusr1_received) {
 			goto skip_fade_out;
 		} else if (!sigint_received && !sighup_received) {
@@ -868,10 +1017,13 @@ faded_out:
 	for (i = 0; i < filters_n; i++)
 		crtc_updates[i].filter.lifespan = LIBCOOPGAMMA_UNTIL_REMOVAL;
 	for (;;) {
+		read_socket(sock);
 		sigusr1_received = 0;
 		if (sigint_received || sighup_received) {
 			for (i = 0; i < filters_n; i++)
 				crtc_updates[i].filter.lifespan = LIBCOOPGAMMA_REMOVE;
+			if (sock >= 0)
+				close(sock);
 			return set_ramps(1, 1, 1);
 		} else if (sigusr2_received) {
 			sigusr2_received -= 1;