looking-glass/client/ivshmem/ivshmem.c
2017-10-29 13:06:41 +11:00

527 lines
No EOL
10 KiB
C

#include "ivshmem.h"
#include "debug.h"
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <stdbool.h>
#include <stdint.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/mman.h>
#define MAX_IRQS 32
struct IVSHMEMServer
{
int64_t version;
int64_t clientID;
int sharedFD;
int irqs[MAX_IRQS];
int irqCount;
};
struct IVSHMEMClient
{
uint16_t clientID;
int irqs[MAX_IRQS];
int irqCount;
struct IVSHMEMClient * last;
struct IVSHMEMClient * next;
};
struct IVSHMEM
{
bool connected;
bool shutdown;
int socket;
struct IVSHMEMServer server;
struct IVSHMEMClient * clients;
off_t mapSize;
void * map;
};
struct IVSHMEM ivshmem =
{
.connected = false,
.shutdown = false,
.socket = -1
};
// ============================================================================
// internal functions
void ivshmem_cleanup();
bool ivshmem_read(void * buffer, const ssize_t size);
bool ivshmem_read_msg(int64_t * index, int *fd);
struct IVSHMEMClient * ivshmem_get_client(uint16_t clientID);
void ivshmem_remove_client(struct IVSHMEMClient * client);
// ============================================================================
bool ivshmem_connect(const char * unix_socket)
{
ivshmem.shutdown = false;
ivshmem.socket = socket(AF_UNIX, SOCK_STREAM, 0);
if (ivshmem.socket < 0)
{
DEBUG_ERROR("socket creation failed");
return false;
}
struct sockaddr_un addr;
addr.sun_family = AF_UNIX;
strncpy(addr.sun_path, unix_socket, sizeof(addr.sun_path));
if (connect(ivshmem.socket, (struct sockaddr *)&addr, sizeof(struct sockaddr_un)) < 0)
{
DEBUG_ERROR("socket connect failed");
ivshmem_cleanup();
return false;
}
ivshmem.connected = true;
if (!ivshmem_read(&ivshmem.server.version, sizeof(ivshmem.server.version)))
{
DEBUG_ERROR("read protocol version failed");
ivshmem_cleanup();
return false;
}
if (ivshmem.server.version != 0)
{
DEBUG_ERROR("unsupported protocol version %ld", ivshmem.server.version);
ivshmem_cleanup();
return false;
}
if (!ivshmem_read(&ivshmem.server.clientID, sizeof(ivshmem.server.clientID)))
{
DEBUG_ERROR("read client id failed");
ivshmem_cleanup();
return false;
}
DEBUG_PROTO("Protocol : %ld", ivshmem.server.version );
DEBUG_PROTO("Client ID: %ld", ivshmem.server.clientID);
if (!ivshmem_read_msg(NULL, &ivshmem.server.sharedFD))
{
DEBUG_ERROR("failed to read shared memory file descriptor");
ivshmem_cleanup();
return false;
}
struct stat stat;
if (fstat(ivshmem.server.sharedFD, &stat) != 0)
{
DEBUG_ERROR("failed to stat shared FD");
ivshmem_cleanup();
return false;
}
ivshmem.mapSize = stat.st_size;
DEBUG_INFO("RAM Size : %ld", ivshmem.mapSize);
ivshmem.map = mmap(
NULL,
stat.st_size,
PROT_READ | PROT_WRITE,
MAP_SHARED,
ivshmem.server.sharedFD,
0);
if (!ivshmem.map)
{
DEBUG_ERROR("failed to map memory");
ivshmem_cleanup();
return false;
}
return true;
}
// ============================================================================
void ivshmem_cleanup()
{
struct IVSHMEMClient * client, * next;
client = ivshmem.clients;
while(client)
{
for(int i = 0; i < client->irqCount; ++i)
close(client->irqs[i]);
next = client->next;
free(client);
client = next;
}
ivshmem.clients = NULL;
for(int i = 0; i < ivshmem.server.irqCount; ++i)
close(ivshmem.server.irqs[i]);
ivshmem.server.irqCount = 0;
if (ivshmem.map)
munmap(ivshmem.map, ivshmem.mapSize);
ivshmem.map = NULL;
ivshmem.mapSize = 0;
if (ivshmem.socket >= 0)
{
ivshmem.shutdown = true;
shutdown(ivshmem.socket, SHUT_RDWR);
close(ivshmem.socket);
ivshmem.socket = -1;
}
ivshmem.connected = false;
}
// ============================================================================
void ivshmem_disconnect()
{
if (!ivshmem.connected)
{
DEBUG_WARN("socket not connected");
return;
}
ivshmem_cleanup();
}
// ============================================================================
bool ivshmem_read(void * buffer, const ssize_t size)
{
if (!ivshmem.connected)
{
DEBUG_ERROR("not connected");
return false;
}
ssize_t len = read(ivshmem.socket, buffer, size);
if (len != size)
{
DEBUG_ERROR("incomplete read");
return false;
}
return true;
}
// ============================================================================
bool ivshmem_read_msg(int64_t * index, int * fd)
{
if (!ivshmem.connected)
{
DEBUG_ERROR("not connected");
return false;
}
struct msghdr msg;
struct iovec iov[1];
union {
struct cmsghdr cmsg;
char control[CMSG_SPACE(sizeof(int))];
} msg_control;
int64_t tmp;
if (!index)
index = &tmp;
iov[0].iov_base = index;
iov[0].iov_len = sizeof(*index);
memset(&msg, 0, sizeof(msg));
msg.msg_iov = iov;
msg.msg_iovlen = 1;
msg.msg_control = &msg_control;
msg.msg_controllen = sizeof(msg_control);
int ret = recvmsg(ivshmem.socket, &msg, 0);
if (ret < sizeof(*index))
{
if (!ivshmem.shutdown)
DEBUG_ERROR("failed to read message\n");
return false;
}
if (ret == 0)
{
if (!ivshmem.shutdown)
DEBUG_ERROR("lost connetion to server\n");
return false;
}
if (!fd)
return true;
*fd = -1;
struct cmsghdr *cmsg;
for(cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg))
{
if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) ||
cmsg->cmsg_level != SOL_SOCKET ||
cmsg->cmsg_type != SCM_RIGHTS)
{
continue;
}
memcpy(fd, CMSG_DATA(cmsg), sizeof(int));
}
return true;
}
// ============================================================================
uint16_t ivshmem_get_id()
{
if (!ivshmem.connected)
{
DEBUG_ERROR("not connected");
return -1;
}
return ivshmem.server.clientID;
}
// ============================================================================
void * ivshmem_get_map()
{
if (!ivshmem.connected)
{
DEBUG_ERROR("not connected");
return NULL;
}
if (!ivshmem.map)
{
DEBUG_ERROR("not mapped");
return NULL;
}
return ivshmem.map;
}
// ============================================================================
size_t ivshmem_get_map_size()
{
if (!ivshmem.connected)
{
DEBUG_ERROR("not connected");
return 0;
}
if (!ivshmem.map)
{
DEBUG_ERROR("not mapped");
return 0;
}
return ivshmem.mapSize;
}
// ============================================================================
struct IVSHMEMClient * ivshmem_get_client(uint16_t clientID)
{
struct IVSHMEMClient * client = NULL;
if (ivshmem.clients == NULL)
{
client = (struct IVSHMEMClient *)malloc(sizeof(struct IVSHMEMClient));
client->clientID = clientID;
client->last = NULL;
client->next = NULL;
client->irqCount = 0;
ivshmem.clients = client;
return client;
}
client = ivshmem.clients;
while(client)
{
if (client->clientID == clientID)
return client;
client = client->next;
}
client = (struct IVSHMEMClient *)malloc(sizeof(struct IVSHMEMClient));
client->clientID = clientID;
client->last = NULL;
client->next = ivshmem.clients;
client->irqCount = 0;
client->next->last = client;
ivshmem.clients = client;
return client;
}
// ============================================================================
void ivshmem_remove_client(struct IVSHMEMClient * client)
{
if (client->last)
client->last->next = client->next;
if (client->next)
client->next->last = client->last;
if (ivshmem.clients == client)
ivshmem.clients = client->next;
free(client);
}
// ============================================================================
bool ivshmem_process()
{
int64_t index;
int fd;
if (!ivshmem_read_msg(&index, &fd))
{
if (!ivshmem.shutdown)
DEBUG_ERROR("failed to read message");
return false;
}
if (index == -1)
{
DEBUG_ERROR("invalid index -1");
return false;
}
if (index > 0xFFFF)
{
DEBUG_ERROR("invalid index > 0xFFFF");
return false;
}
if (index == ivshmem.server.clientID)
{
if (fd == -1)
{
DEBUG_ERROR("server sent disconnect");
return false;
}
if (ivshmem.server.irqCount == MAX_IRQS)
{
DEBUG_WARN("maximum IRQs reached, closing extra");
close(fd);
return true;
}
ivshmem.server.irqs[ivshmem.server.irqCount++] = fd;
return true;
}
struct IVSHMEMClient * client = ivshmem_get_client(index);
if (!client)
{
DEBUG_ERROR("failed to get/create client record");
return false;
}
if (fd == -1)
{
DEBUG_PROTO("remove client %u", client->clientID);
ivshmem_remove_client(client);
return true;
}
if (client->irqCount == MAX_IRQS)
{
DEBUG_WARN("maximum client IRQs reached, closing extra");
close(fd);
return true;
}
client->irqs[client->irqCount++] = fd;
return true;
}
// ============================================================================
enum IVSHMEMWaitResult ivshmem_wait_irq(uint16_t vector)
{
if (vector > ivshmem.server.irqCount - 1)
return false;
int fd = ivshmem.server.irqs[vector];
fd_set fds;
FD_ZERO(&fds);
FD_SET(fd, &fds);
struct timeval timeout;
timeout.tv_sec = 1;
timeout.tv_usec = 0;
while(true)
{
int ret = select(fd+1, &fds, NULL, NULL, &timeout);
if (ret < 0)
{
if (errno == EINTR)
continue;
DEBUG_ERROR("select error");
break;
}
if (ret == 0)
return IVSHMEM_WAIT_RESULT_TIMEOUT;
if (FD_ISSET(fd, &fds))
{
uint64_t kick;
read(fd, &kick, sizeof(kick));
return IVSHMEM_WAIT_RESULT_OK;
}
}
return IVSHMEM_WAIT_RESULT_ERROR;
}
// ============================================================================
bool ivshmem_kick_irq(uint16_t clientID, uint16_t vector)
{
struct IVSHMEMClient * client = ivshmem_get_client(clientID);
if (!client)
{
DEBUG_ERROR("invalid client");
return false;
}
if (vector > client->irqCount - 1)
{
DEBUG_ERROR("invalid vector for client");
return false;
}
int fd = client->irqs[vector];
uint64_t kick = ivshmem.server.clientID;
if (write(fd, &kick, sizeof(kick)) == sizeof(kick))
return true;
DEBUG_ERROR("failed to send kick");
return false;
}