/**
* coopgammad -- Cooperative gamma server
* Copyright (C) 2016 Mattias Andrée (maandree@kth.se)
*
* This library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
#include "server.h"
#include "output.h"
#include "util.h"
#include <sys/select.h>
#include <sys/socket.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
/**
* List of all client's file descriptors
*
* Unused slots, with index less than `connections_used`,
* should have the value -1 (negative)
*/
int* connections = NULL;
/**
* The number of elements allocated for `connections`
*/
size_t connections_alloc = 0;
/**
* The index of the first unused slot in `connections`
*/
size_t connections_ptr = 0;
/**
* The index of the last used slot in `connections`, plus 1
*/
size_t connections_used = 0;
/**
* The clients' connections' message buffers
*/
struct message* client_messages = NULL;
/**
* The name of the process
*/
extern char* argv0;
/**
* The server socket's file descriptor
*/
extern int socketfd;
/**
* Has the process receive a signal
* telling it to re-execute?
*/
extern volatile sig_atomic_t reexec;
/**
* Has the process receive a signal
* telling it to terminate?
*/
extern volatile sig_atomic_t terminate;
/**
* Array of all outputs
*/
extern struct output* outputs;
/**
* The nubmer of elements in `outputs`
*/
extern size_t outputs_n;
/**
* Destroy the state of the connections
*
* @param disconnect Disconnect all connections?
*/
void server_destroy(int disconnect)
{
size_t i;
for (i = 0; i < connections_used; i++)
if (connections[i] >= 0)
{
if (disconnect)
{
shutdown(connections[i], SHUT_RDWR);
close(connections[i]);
}
message_destroy(client_messages + i);
}
free(client_messages);
free(connections);
}
/**
* Marshal the state of the connections
*
* @param buf Output buffer for the marshalled data,
* `NULL` to only measure how many bytes
* this buffer needs
* @return The number of marshalled bytes
*/
size_t server_marshal(void* buf)
{
size_t i, off = 0;
char* bs = buf;
if (bs != NULL)
*(size_t*)(bs + off) = connections_ptr;
off += sizeof(size_t);
if (bs != NULL)
*(size_t*)(bs + off) = connections_used;
off += sizeof(size_t);
if (bs != NULL)
memcpy(bs + off, connections, connections_used * sizeof(*connections));
off += connections_used * sizeof(*connections);
for (i = 0; i < connections_used; i++)
if (connections[i] >= 0)
off += message_marshal(client_messages + i, bs ? bs + off : NULL);
return off;
}
/**
* Unmarshal the state of the connections
*
* @param buf Buffer for the marshalled data
* @return The number of unmarshalled bytes, 0 on error
*/
size_t server_unmarshal(const void* buf)
{
size_t off = 0, i, n;
const char* bs = buf;
connections = NULL;
client_messages = NULL;
connections_ptr = *(const size_t*)(bs + off);
off += sizeof(size_t);
connections_alloc = connections_used = *(const size_t*)(bs + off);
off += sizeof(size_t);
if (connections_alloc > 0)
{
connections = memdup(bs + off, connections_alloc * sizeof(*connections));
if (connections == NULL)
return 0;
off += connections_used * sizeof(*connections);
client_messages = malloc(connections_alloc * sizeof(*client_messages));
if (client_messages == NULL)
return 0;
}
for (i = 0; i < connections_used; i++)
if (connections[i] >= 0)
{
off += n = message_unmarshal(client_messages + i, bs ? bs + off : NULL);
if (n == 0)
return 0;
}
return off;
}
/**
* Sets the file descriptor set that includes
* the server socket and all connections
*
* @param fds The file descritor set
* @return The highest set file descritor plus 1
*/
static int update_fdset(fd_set* fds)
{
int fdmax = socketfd;
size_t i;
FD_ZERO(fds);
FD_SET(socketfd, fds);
for (i = 0; i < connections_used; i++)
if (connections[i] >= 0)
{
FD_SET(connections[i], fds);
if (fdmax < connections[i])
fdmax = connections[i];
}
return fdmax + 1;
}
/**
* Handle event on the server socket
*
* @return 1: New connection accepted
* 0: Successful
* -1: Failure
*/
static int handle_server(void)
{
int fd, flags, saved_errno;
fd = accept(socketfd, NULL, NULL);
if (fd < 0)
switch (errno)
{
case EINTR:
return 0;
case ECONNABORTED:
case EINVAL:
terminate = 1;
return 0;
default:
return -1;
}
flags = fcntl(fd, F_GETFL);
if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1)
goto fail;
if (connections_ptr == connections_alloc)
{
void* new;
new = realloc(connections, (connections_alloc + 10) * sizeof(*connections));
if (new == NULL)
goto fail;
connections = new;
connections[connections_ptr] = fd;
new = realloc(client_messages, (connections_alloc + 10) * sizeof(*client_messages));
if (new == NULL)
goto fail;
client_messages = new;
connections_alloc += 10;
if (message_initialise(client_messages + connections_ptr))
goto fail;
}
connections_ptr++;
while (connections_ptr < connections_used)
if (connections[connections_ptr] >= 0)
connections_ptr++;
if (connections_used < connections_ptr)
connections_used = connections_ptr;
return 1;
fail:
saved_errno = errno;
shutdown(fd, SHUT_RDWR);
close(fd);
errno = saved_errno;
return -1;
}
/**
* Handle a closed connection
*
* @param client The file descriptor for the client
* @retunr Zero on success, -1 on error
*/
static int connection_closed(int client)
{
size_t i, j, k;
int remove;
for (i = 0; i < outputs_n; i++)
{
struct output* output = outputs + i;
ssize_t updated = -1;
for (j = k = 0; j < output->table_size; j += !remove, k++)
{
remove = output->table_filters[j].client == client;
if (remove)
{
filter_destroy(output->table_filters + j);
libgamma_gamma_ramps8_destroy(&(output->table_sums[j].u8));
output->table_size -= 1;
if (updated == -1)
updated = (ssize_t)j;
}
output->table_filters[j] = output->table_filters[k];
output->table_sums[j] = output->table_sums[k];
}
if (updated >= 0)
flush_filters(output, (size_t)updated);
}
return 0;
}
/**
* Handle a ‘Command: enumerate-crtcs’ message
*
* @param conn The index of the connection
* @return Zero on success (even if ignored), -1 on error
*/
static int enumerate_crtcs(size_t conn)
{
/* TODO */ (void) conn;
return 0;
}
/**
* Handle a ‘Command: set-gamma’ message
*
* @param conn The index of the connection
* @param crtc The value of the ‘CRTC’ header
* @return Zero on success (even if ignored), -1 on error
*/
static int get_gamma_info(size_t conn, char* crtc)
{
if (crtc == NULL)
return fprintf(stderr, "%s: ignoring incomplete Command: get-gamma-info message\n", argv0), 0;
/* TODO */ (void) conn;
return 0;
}
/**
* Handle a ‘Command: get-gamma’ message
*
* @param conn The index of the connection
* @param crtc The value of the ‘CRTC’ header
* @param coalesce The value of the ‘Coalesce’ header
* @param high_priority The value of the ‘High priority’ header
* @param low_priority The value of the ‘Low priority’ header
* @return Zero on success (even if ignored), -1 on error
*/
static int get_gamma(size_t conn, char* crtc, char* coalesce, char* high_priority, char* low_priority)
{
int64_t high, low;
int coal;
if ((crtc == NULL) ||
(coalesce == NULL) ||
(high_priority == NULL) ||
(low_priority == NULL))
return fprintf(stderr, "%s: ignoring incomplete Command: get-gamma message\n", argv0), 0;
high = (int64_t)atoll(high_priority);
low = (int64_t)atoll(low_priority);
if (!strcmp(coalesce, "yes"))
coal = 1;
else if (!strcmp(coalesce, "no"))
coal = 0;
else
return fprintf(stderr, "%s: ignoring Command: get-gamma message with bad Coalesce value: %s\n",
argv0, coalesce), 0;
/* TODO */ (void) coal, (void) high, (void) low, (void) conn;
return 0;
}
/**
* Handle a ‘Command: set-gamma’ message
*
* @param conn The index of the connection
* @param crtc The value of the ‘CRTC’ header
* @param priority The value of the ‘Priority’ header
* @param class The value of the ‘Class’ header
* @param lifespan The value of the ‘Lifespan’ header
* @return Zero on success (even if ignored), -1 on error
*/
static int set_gamma(size_t conn, char* crtc, char* priority, char* class, char* lifespan)
{
struct message* msg = client_messages + conn;
struct output* output = NULL;
struct filter filter;
char* p;
char* q;
int saved_errno;
ssize_t r;
if ((crtc == NULL) ||
(priority == NULL) ||
(class == NULL) ||
(lifespan == NULL))
return fprintf(stderr, "%s: ignoring incomplete Command: set-gamma message\n", argv0), 0;
filter.client = connections[conn];
filter.priority = (int64_t)atoll(priority);
filter.ramps = NULL;
output = output_find_by_name(crtc, outputs, outputs_n);
if (output == NULL)
return fprintf(stderr, "%s: ignoring Command: set-gamma message with non-existing CRTC: %s\n",
argv0, crtc), 0;
p = strstr(class, "::");
if ((p == NULL) || (p == class))
return fprintf(stderr, "%s: ignoring Command: set-gamma message with malformatted class: %s\n",
argv0, class), 0;
q = strstr(p + 2, "::");
if ((q == NULL) || (q == p))
return fprintf(stderr, "%s: ignoring Command: set-gamma message with malformatted class: %s\n",
argv0, class), 0;
if (!strcmp(lifespan, "until-removal"))
filter.lifespan = LIFESPAN_UNTIL_REMOVAL;
else if (!strcmp(lifespan, "until-death"))
filter.lifespan = LIFESPAN_UNTIL_DEATH;
else if (!strcmp(lifespan, "remove"))
filter.lifespan = LIFESPAN_REMOVE;
else
return fprintf(stderr, "%s: ignoring Command: set-gamma message with bad lifetime: %s\n",
argv0, lifespan), 0;
if (filter.lifespan == LIFESPAN_REMOVE)
{
if (msg->payload_size)
fprintf(stderr, "%s: ignoring superfluous playload on Command: set-gamma message with "
"Lifespan: remove\n", argv0);
}
else if (msg->payload_size != output->ramps_size)
return fprintf(stderr, "%s: ignoring Command: set-gamma message bad payload: size: %zu instead of %zu\n",
argv0, msg->payload_size, output->ramps_size), 0;
filter.class = memdup(class, strlen(class) + 1);
if (filter.class == NULL)
goto fail;
if (filter.lifespan != LIFESPAN_REMOVE)
{
filter.ramps = memdup(msg->payload, msg->payload_size);
if (filter.ramps == NULL)
goto fail;
}
if ((r = add_filter(output, &filter)) < 0)
goto fail;
filter.class = NULL;
filter.ramps = NULL;
if (flush_filters(output, (size_t)r))
goto fail;
return 0;
fail:
saved_errno = errno;
free(filter.class);
free(filter.ramps);
errno = saved_errno;
return -1;
}
/**
* Handle event on a connection to a client
*
* @param conn The index of the connection
* @return 1: The connection as closed
* 0: Successful
* -1: Failure
*/
static int handle_connection(size_t conn)
{
struct message* msg = client_messages + conn;
int r, fd = connections[conn];
char* command = NULL;
char* crtc = NULL;
char* coalesce = NULL;
char* high_priority = NULL;
char* low_priority = NULL;
char* priority = NULL;
char* class = NULL;
char* lifespan = NULL;
size_t i;
again:
switch (message_read(msg, fd))
{
default:
break;
case -1:
switch (errno)
{
case EINTR:
case EAGAIN:
#if EAGAIN != EWOULDBLOCK
case EWOULDBLOCK:
#endif
return 0;
default:
return -1;
case ECONNRESET:;
/* Fall throught to `case -2` in outer switch. */
}
case -2:
shutdown(fd, SHUT_RDWR);
close(fd);
connections[conn] = -1;
if (conn < connections_ptr)
connections_ptr = conn;
if (conn == connections_used)
connections_used -= 1;
message_destroy(msg);
connection_closed(fd);
return 1;
}
for (i = 0; i < msg->header_count; i++)
{
char* header = msg->headers[i];
if (strstr(header, "Command: ") == header) command = strstr(header, ": ") + 2;
else if (strstr(header, "CRTC: ") == header) crtc = strstr(header, ": ") + 2;
else if (strstr(header, "Coalesce: ") == header) coalesce = strstr(header, ": ") + 2;
else if (strstr(header, "High priority: ") == header) high_priority = strstr(header, ": ") + 2;
else if (strstr(header, "Low priority: ") == header) low_priority = strstr(header, ": ") + 2;
else if (strstr(header, "Priority: ") == header) priority = strstr(header, ": ") + 2;
else if (strstr(header, "Class: ") == header) class = strstr(header, ": ") + 2;
else if (strstr(header, "Lifespan: ") == header) lifespan = strstr(header, ": ") + 2;
else
fprintf(stderr, "%s: ignoring unrecognised header: %s\n", argv0, header);
}
r = 0;
if (command == NULL)
fprintf(stderr, "%s: ignoring message without command header\n", argv0);
else if (!strcmp(command, "enumerate-crtcs"))
{
if (crtc || coalesce || high_priority || low_priority || priority || class || lifespan)
fprintf(stderr, "%s: ignoring superfluous headers in Command: enumerate-crtcs message\n", argv0);
r = enumerate_crtcs(conn);
}
else if (!strcmp(command, "get-gamma-info"))
{
if (coalesce || high_priority || low_priority || priority || class || lifespan)
fprintf(stderr, "%s: ignoring superfluous headers in Command: get-gamma-info message\n", argv0);
r = get_gamma_info(conn, crtc);
}
else if (!strcmp(command, "get-gamma"))
{
if (priority || class || lifespan)
fprintf(stderr, "%s: ignoring superfluous headers in Command: get-gamma message\n", argv0);
r = get_gamma(conn, crtc, coalesce, high_priority, low_priority);
}
else if (!strcmp(command, "set-gamma"))
{
if (coalesce || high_priority || low_priority)
fprintf(stderr, "%s: ignoring superfluous headers in Command: set-gamma message\n", argv0);
r = set_gamma(conn, crtc, priority, class, lifespan);
}
else
fprintf(stderr, "%s: ignoring unrecognised command: Command: %s\n", argv0, command);
if (r < 0)
return -1;
goto again;
}
/**
* The program's main loop
*
* @return Zero on success, -1 on error
*/
int main_loop(void)
{
fd_set fds_orig, fds_read, fds_ex;
int i, r, update, fdn = update_fdset(&fds_orig);
size_t j;
while (!reexec && !terminate)
{
memcpy(&fds_read, &fds_orig, sizeof(fd_set));
memcpy(&fds_ex, &fds_orig, sizeof(fd_set));
if (select(fdn, &fds_read, NULL, &fds_ex, NULL) < 0)
{
if (errno == EINTR)
continue;
return -1;
}
update = 0;
for (i = 0; i < fdn; i++)
if (FD_ISSET(i, &fds_read) || FD_ISSET(i, &fds_ex))
{
if (i == socketfd)
r = handle_server();
else
{
for (j = 0;; j++)
if (connections[j] == i)
break;
r = handle_connection(j);
}
switch (r)
{
case 0:
break;
case 1:
update = 1;
break;
default:
return -1;
}
}
if (update)
update_fdset(&fds_orig);
}
return 0;
}
