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sock.c
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sock.c
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#include <fcntl.h>
#include <netinet/tcp.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/un.h>
#include "kernel/calls.h"
#include "kernel/task.h"
#include "fs/fd.h"
#include "fs/inode.h"
#include "fs/path.h"
#include "fs/real.h"
#include "fs/sock.h"
#include "debug.h"
#define SOCKET_TYPE_MASK 0xf
const struct fd_ops socket_fdops;
static lock_t peer_lock = LOCK_INITIALIZER;
static fd_t sock_fd_create(int sock_fd, int domain, int type, int protocol) {
struct fd *fd = adhoc_fd_create(&socket_fdops);
if (fd == NULL)
return _ENOMEM;
fd->stat.mode = S_IFSOCK | 0666;
fd->real_fd = sock_fd;
fd->socket.domain = domain;
fd->socket.type = type & SOCKET_TYPE_MASK;
fd->socket.protocol = protocol;
if (domain == AF_LOCAL_) {
cond_init(&fd->socket.unix_got_peer);
list_init(&fd->socket.unix_scm);
}
return f_install(fd, type & ~SOCKET_TYPE_MASK);
}
int_t sys_socket(dword_t domain, dword_t type, dword_t protocol) {
STRACE("socket(%d, %d, %d)", domain, type, protocol);
int real_domain = sock_family_to_real(domain);
if (real_domain < 0)
return _EINVAL;
int real_type = sock_type_to_real(type, protocol);
if (real_type < 0)
return _EINVAL;
// this hack makes mtr work
if (type == SOCK_RAW_ && protocol == IPPROTO_RAW)
protocol = IPPROTO_ICMP;
int sock = socket(real_domain, real_type, protocol);
if (sock < 0)
return errno_map();
#ifdef __APPLE__
if (domain == AF_INET_ && type == SOCK_DGRAM_) {
// in some cases, such as ICMP, datagram sockets on mac can default to
// including the IP header like raw sockets
int one = 1;
setsockopt(sock, IPPROTO_IP, IP_STRIPHDR, &one, sizeof(one));
}
#endif
fd_t f = sock_fd_create(sock, domain, type, protocol);
if (f < 0)
close(sock);
return f;
}
static void inode_release_if_exist(struct inode_data *inode) {
if (inode != NULL)
inode_release(inode);
}
static struct fd *sock_getfd(fd_t sock_fd) {
struct fd *sock = f_get(sock_fd);
if (sock == NULL || sock->ops != &socket_fdops)
return NULL;
return sock;
}
static uint32_t unix_socket_next_id(void) {
static uint32_t next_id = 0;
static lock_t next_id_lock = LOCK_INITIALIZER;
lock(&next_id_lock, 0);
uint32_t id = ++next_id;
unlock(&next_id_lock);
return id;
}
static int unix_socket_get(const char *path_raw, struct fd *bind_fd, uint32_t *socket_id) {
char path[MAX_PATH];
int err = path_normalize(AT_PWD, path_raw, path, N_SYMLINK_FOLLOW);
if (err < 0)
return err;
struct mount *mount = find_mount_and_trim_path(path);
struct statbuf stat;
err = mount->fs->stat(mount, path, &stat);
// If bind was called, there are some funny semantics.
if (bind_fd != NULL) {
// If the file exists, fail.
if (err == 0) {
err = _EADDRINUSE;
goto out;
}
// If the file can't be found, try to create it as a socket.
if (err < 0) {
mode_t_ mode = 0777;
struct fs_info *fs = current->fs;
lock(&fs->lock, 0);
mode &= ~fs->umask;
unlock(&fs->lock);
err = mount->fs->mknod(mount, path, S_IFSOCK | mode, 0);
if (err < 0)
goto out;
err = mount->fs->stat(mount, path, &stat);
if (err < 0)
goto out;
}
}
// If something other than bind was called, just do the obvious thing and
// fail if stat failed.
if (bind_fd == NULL && err < 0)
goto out;
if (!S_ISSOCK(stat.mode)) {
err = _ENOTSOCK;
goto out;
}
// Look up the socket ID for the inode number.
struct inode_data *inode = inode_get(mount, stat.inode);
lock(&inode->lock, 0);
if (inode->socket_id == 0)
inode->socket_id = unix_socket_next_id();
unlock(&inode->lock);
*socket_id = inode->socket_id;
mount_release(mount);
if (bind_fd != NULL)
bind_fd->socket.unix_name_inode = inode;
else
inode_release(inode);
return 0;
out:
mount_release(mount);
return err;
}
// Dan Bernstein's simple and decently effective hash function
static uint32_t str_hash(const char *str) {
uint32_t hash = 5381;
for (int i = 0; str[i] != '\0'; i++) {
hash = 33 * hash ^ str[i];
}
return hash;
}
// The abstract socket namespace is a lot simpler than it sounds: if the first
// byte of the path is a null byte, then it gets looked up in this hashtable
// instead of the filesystem.
struct unix_abstract {
unsigned refcount;
uint32_t hash;
uint32_t socket_id;
struct list links;
};
#define ABSTRACT_HASH_SIZE 1024
static struct list abstract_hash[ABSTRACT_HASH_SIZE];
static lock_t unix_abstract_lock = LOCK_INITIALIZER;
static int unix_abstract_get(const char *name, struct fd *bind_fd, uint32_t *socket_id) {
uint32_t hash = str_hash(name);
lock(&unix_abstract_lock, 0);
struct unix_abstract *sock_tmp;
struct unix_abstract *sock = NULL;
struct list *bucket = &abstract_hash[hash % ABSTRACT_HASH_SIZE];
if (list_null(bucket))
list_init(bucket);
list_for_each_entry(bucket, sock_tmp, links) {
if (sock_tmp->hash == hash) {
sock = sock_tmp;
break;
}
}
if (bind_fd != NULL && sock != NULL) {
unlock(&unix_abstract_lock);
return _EEXIST;
}
if (bind_fd == NULL && sock == NULL) {
unlock(&unix_abstract_lock);
return _ENOENT;
}
if (sock == NULL) {
sock = malloc(sizeof(struct unix_abstract));
sock->refcount = 0;
sock->hash = hash;
sock->socket_id = unix_socket_next_id();
list_add(bucket, &sock->links);
}
sock->refcount++;
unlock(&unix_abstract_lock);
*socket_id = sock->socket_id;
if (bind_fd != NULL)
bind_fd->socket.unix_name_abstract = sock;
return 0;
}
static void unix_abstract_release(struct unix_abstract *name) {
lock(&unix_abstract_lock, 0);
if (--name->refcount == 0) {
list_remove(&name->links);
free(name);
}
unlock(&unix_abstract_lock);
}
const char *sock_tmp_prefix = "/tmp/ishsock";
static int sockaddr_read_bind(addr_t sockaddr_addr, void *sockaddr, uint_t *sockaddr_len, struct fd *bind_fd) {
// Make sure we can read things without overflowing buffers
if (*sockaddr_len < 2)
return _EINVAL;
if (*sockaddr_len > sizeof(struct sockaddr_max_))
return _EINVAL;
if (user_read(sockaddr_addr, sockaddr, *sockaddr_len))
return _EFAULT;
struct sockaddr *real_addr = sockaddr;
struct sockaddr_ *fake_addr = sockaddr;
real_addr->sa_family = sock_family_to_real(fake_addr->family);
switch (real_addr->sa_family) {
case PF_INET:
if (*sockaddr_len < sizeof(struct sockaddr_in))
return _EINVAL;
break;
case PF_INET6:
if (*sockaddr_len < sizeof(struct sockaddr_in6))
return _EINVAL;
break;
case PF_LOCAL: {
// First pull out the path, being careful to not overflow anything.
char path[SOCKADDR_DATA_MAX + 1];
size_t path_size = *sockaddr_len - offsetof(struct sockaddr_, data);
memcpy(path, fake_addr->data, path_size);
path[path_size] = '\0';
uint32_t socket_id;
int err;
if (path_size == 0) {
return _ENOENT;
} else if (path[0] != '\0') {
STRACE(" unix socket %s", path);
err = unix_socket_get(path, bind_fd, &socket_id);
} else {
STRACE(" unix abstract socket %s", path + 1);
err = unix_abstract_get(path + 1, bind_fd, &socket_id);
}
if (err < 0)
return err;
if (bind_fd != NULL) {
bind_fd->socket.unix_name_len = path_size;
memcpy(bind_fd->socket.unix_name, path, path_size);
}
struct sockaddr_un *real_addr_un = sockaddr;
size_t path_len = sprintf(real_addr_un->sun_path, "%s%d.%u", sock_tmp_prefix, getpid(), socket_id);
// The call to real bind will fail if the backing socket already
// exists from a previous run or something. We already checked that
// the fake file doesn't exist in unix_socket_get, so try a simple
// solution.
if (bind_fd != NULL)
unlink(real_addr_un->sun_path);
*sockaddr_len = offsetof(struct sockaddr_un, sun_path) + path_len;
break;
}
default:
return _EINVAL;
}
return 0;
}
static int sockaddr_read(addr_t sockaddr_addr, void *sockaddr, uint_t *sockaddr_len) {
struct inode_data *inode = NULL;
int err = sockaddr_read_bind(sockaddr_addr, sockaddr, sockaddr_len, NULL);
inode_release_if_exist(inode);
return err;
}
static int sockaddr_write(addr_t sockaddr_addr, void *sockaddr, uint_t buffer_len, uint_t *sockaddr_len) {
struct sockaddr *real_addr = sockaddr;
struct sockaddr_ *fake_addr = sockaddr;
fake_addr->family = sock_family_from_real(real_addr->sa_family);
switch (fake_addr->family) {
case PF_LOCAL_: {
// Most callers of sockaddr_write use it to return a peer name, and
// since we don't know the peer name in this case, just return the
// default peer name, which is the null address.
static struct sockaddr_ unix_domain_null = {.family = PF_LOCAL_};
sockaddr = &unix_domain_null;
*sockaddr_len = sizeof(unix_domain_null);
break;
}
case PF_INET_:
case PF_INET6_:
break;
default:
return _EINVAL;
}
if (buffer_len > *sockaddr_len)
buffer_len = *sockaddr_len;
// The address is supposed to be truncated if the specified length is too
// short, instead of returning an error.
if (user_write(sockaddr_addr, sockaddr, buffer_len))
return _EFAULT;
return 0;
}
int_t sys_bind(fd_t sock_fd, addr_t sockaddr_addr, uint_t sockaddr_len) {
STRACE("bind(%d, 0x%x, %d)", sock_fd, sockaddr_addr, sockaddr_len);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
struct sockaddr_max_ sockaddr;
struct inode_data *inode = NULL;
int err = sockaddr_read_bind(sockaddr_addr, &sockaddr, &sockaddr_len, sock);
if (err < 0)
return err;
err = bind(sock->real_fd, (void *) &sockaddr, sockaddr_len);
if (err < 0) {
inode_release_if_exist(sock->socket.unix_name_inode);
if (sock->socket.unix_name_abstract != NULL)
unix_abstract_release(sock->socket.unix_name_abstract);
return errno_map();
}
sock->socket.unix_name_inode = inode;
return 0;
}
static void fill_cred(struct ucred_ *cred) {
cred->pid = current->pid;
cred->uid = current->euid;
cred->gid = current->egid;
}
int_t sys_connect(fd_t sock_fd, addr_t sockaddr_addr, uint_t sockaddr_len) {
STRACE("connect(%d, 0x%x, %d)", sock_fd, sockaddr_addr, sockaddr_len);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
struct sockaddr_max_ sockaddr;
int err = sockaddr_read(sockaddr_addr, &sockaddr, &sockaddr_len);
if (err < 0)
return err;
err = connect(sock->real_fd, (void *) &sockaddr, sockaddr_len);
if (err < 0)
return errno_map();
if (sock->socket.domain == AF_LOCAL_) {
fill_cred(&sock->socket.unix_cred);
assert(sock->socket.unix_peer == NULL);
// Send a pointer to ourselves to the other end so they can set up the peer pointers.
ssize_t res = write(sock->real_fd, &sock, sizeof(struct fd *));
if (res == sizeof(struct fd *)) {
// Wait for acknowledgement that it happened.
lock(&peer_lock, 0);
TASK_MAY_BLOCK {
while (sock->socket.unix_peer == NULL)
wait_for_ignore_signals(&sock->socket.unix_got_peer, &peer_lock, NULL);
}
unlock(&peer_lock);
}
}
return err;
}
int_t sys_listen(fd_t sock_fd, int_t backlog) {
STRACE("listen(%d, %d)", sock_fd, backlog);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
int err = listen(sock->real_fd, backlog);
if (err < 0)
return errno_map();
sockrestart_begin_listen(sock);
return err;
}
int_t sys_accept(fd_t sock_fd, addr_t sockaddr_addr, addr_t sockaddr_len_addr) {
STRACE("accept(%d, 0x%x, 0x%x)", sock_fd, sockaddr_addr, sockaddr_len_addr);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
dword_t sockaddr_len = 0;
if (sockaddr_addr != 0) {
if (user_get(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
}
char sockaddr[sockaddr_len];
int client =0;
TASK_MAY_BLOCK {
do {
sockrestart_begin_listen_wait(sock);
errno = 0;
client = accept(sock->real_fd,
sockaddr_addr != 0 ? (void *) sockaddr : NULL,
sockaddr_addr != 0 ? &sockaddr_len : NULL);
sockrestart_end_listen_wait(sock);
} while (sockrestart_should_restart_listen_wait(0) && errno == EINTR);
}
if (client < 0)
return errno_map();
if (sockaddr_addr != 0) {
int err = sockaddr_write(sockaddr_addr, sockaddr, sizeof(sockaddr), &sockaddr_len);
if (err < 0)
return client;
if (user_put(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
}
fd_t client_f = sock_fd_create(client,
sock->socket.domain, sock->socket.type, sock->socket.protocol);
if (client_f < 0)
close(client);
if (sock->socket.domain == AF_LOCAL_) {
lock(&peer_lock, 0);
struct fd *client_fd = f_get(client_f);
fill_cred(&client_fd->socket.unix_cred);
struct fd *peer;
ssize_t res = read(client, &peer, sizeof(peer));
if (res == sizeof(peer)) {
client_fd->socket.unix_peer = peer;
peer->socket.unix_peer = client_fd;
notify(&peer->socket.unix_got_peer);
}
unlock(&peer_lock);
}
return client_f;
}
static void copy_unix_name(char *sockaddr, dword_t *sockaddr_len, struct fd *sock) {
struct sockaddr_ *fake_addr = (void *) sockaddr;
fake_addr->family = PF_LOCAL_;
size_t data_len = *sockaddr_len - offsetof(struct sockaddr_, data);
size_t name_len = sock->socket.unix_name_len;
if (name_len > data_len)
name_len = data_len;
memset(fake_addr->data, 0, data_len);
memcpy(fake_addr->data, sock->socket.unix_name, name_len);
*sockaddr_len = offsetof(struct sockaddr_, data) + name_len;
}
int_t sys_getsockname(fd_t sock_fd, addr_t sockaddr_addr, addr_t sockaddr_len_addr) {
STRACE("getsockname(%d, 0x%x, 0x%x)", sock_fd, sockaddr_addr, sockaddr_len_addr);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
dword_t sockaddr_len;
if (user_get(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
char sockaddr[sockaddr_len];
// if this is a unix socket, return the same string passed to bind
if (sock->socket.domain == PF_LOCAL_) {
copy_unix_name(sockaddr, &sockaddr_len, sock);
if (user_write(sockaddr_addr, sockaddr, sizeof(sockaddr)))
return _EFAULT;
if (user_put(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
return 0;
}
int res = getsockname(sock->real_fd, (void *) sockaddr, &sockaddr_len);
if (res < 0)
return errno_map();
int err = sockaddr_write(sockaddr_addr, sockaddr, sizeof(sockaddr), &sockaddr_len);
if (err < 0)
return err;
if (user_put(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
return res;
}
int_t sys_getpeername(fd_t sock_fd, addr_t sockaddr_addr, addr_t sockaddr_len_addr) {
STRACE("getpeername(%d, 0x%x, 0x%x)", sock_fd, sockaddr_addr, sockaddr_len_addr);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
dword_t sockaddr_len;
if (user_get(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
// TODO if this is a unix socket, return the same string the peer passed to
// bind once the peer pointer is available
char sockaddr[sockaddr_len];
int res = getpeername(sock->real_fd, (void *) sockaddr, &sockaddr_len);
if (res < 0)
return errno_map();
int err = sockaddr_write(sockaddr_addr, sockaddr, sizeof(sockaddr), &sockaddr_len);
if (err < 0)
return err;
if (user_put(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
return res;
}
int_t sys_socketpair(dword_t domain, dword_t type, dword_t protocol, addr_t sockets_addr) {
STRACE("socketpair(%d, %d, %d, 0x%x)", domain, type, protocol, sockets_addr);
int real_domain = sock_family_to_real(domain);
if (real_domain < 0)
return _EINVAL;
int real_type = sock_type_to_real(type, protocol);
if (real_type < 0)
return _EINVAL;
int sockets[2];
int err = socketpair(domain, type, protocol, sockets);
if (err < 0)
return errno_map();
lock(&peer_lock, 0);
int fake_sockets[2];
err = fake_sockets[0] = sock_fd_create(sockets[0], domain, type, protocol);
if (fake_sockets[0] < 0) {
unlock(&peer_lock);
goto close_sockets;
}
err = fake_sockets[1] = sock_fd_create(sockets[1], domain, type, protocol);
if (fake_sockets[1] < 0) {
unlock(&peer_lock);
goto close_fake_0;
}
struct fd *sock1 = f_get(fake_sockets[0]);
struct fd *sock2 = f_get(fake_sockets[1]);
sock1->socket.unix_peer = sock2;
sock2->socket.unix_peer = sock1;
unlock(&peer_lock);
err = _EFAULT;
if (user_put(sockets_addr, fake_sockets))
goto close_fake_1;
STRACE(" [%d, %d]", fake_sockets[0], fake_sockets[1]);
return 0;
close_fake_1:
sys_close(fake_sockets[1]);
close_fake_0:
sys_close(fake_sockets[0]);
close_sockets:
close(sockets[0]);
close(sockets[1]);
return err;
}
int_t sys_sendto(fd_t sock_fd, addr_t buffer_addr, dword_t len, dword_t flags, addr_t sockaddr_addr, dword_t sockaddr_len) {
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
char *buffer = malloc(len + 1);
if (user_read(buffer_addr, buffer, len))
return _EFAULT;
buffer[len] = '\0';
STRACE("sendto(%d, \"%.100s\", %d, %d, 0x%x, %d)", sock_fd, buffer, len, flags, sockaddr_addr, sockaddr_len);
int real_flags = sock_flags_to_real(flags);
int err = _EINVAL;
if (real_flags < 0)
goto error;
struct sockaddr_max_ sockaddr;
if (sockaddr_addr) {
err = sockaddr_read(sockaddr_addr, &sockaddr, &sockaddr_len);
if (err < 0)
goto error;
}
ssize_t res = 0;
TASK_MAY_BLOCK {
res = sendto(sock->real_fd, buffer, len, real_flags,
sockaddr_addr ? (void *) &sockaddr : NULL, sockaddr_len);
}
free(buffer);
if (res < 0)
return errno_map();
return res;
error:
free(buffer);
return err;
}
int_t sys_recvfrom(fd_t sock_fd, addr_t buffer_addr, dword_t len, dword_t flags, addr_t sockaddr_addr, addr_t sockaddr_len_addr) {
STRACE("recvfrom(%d, 0x%x, %d, %d, 0x%x, 0x%x)", sock_fd, buffer_addr, len, flags, sockaddr_addr, sockaddr_len_addr);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
int real_flags = sock_flags_to_real(flags);
if (real_flags < 0)
return _EINVAL;
uint_t sockaddr_len = 0;
if (sockaddr_len_addr != 0)
if (user_get(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
char *buffer = malloc(len);
char sockaddr[sockaddr_len];
ssize_t res = 0;
TASK_MAY_BLOCK {
res = recvfrom(sock->real_fd, buffer, len, real_flags,
sockaddr_addr != 0 ? (void *) sockaddr : NULL,
sockaddr_len_addr != 0 ? &sockaddr_len : NULL);
}
if (res < 0) {
free(buffer);
return errno_map();
}
if (user_write(buffer_addr, buffer, len)) {
free(buffer);
return _EFAULT;
}
free(buffer);
if (sockaddr_addr != 0) {
int err = sockaddr_write(sockaddr_addr, sockaddr, sizeof(sockaddr), &sockaddr_len);
if (err < 0)
return err;
}
if (sockaddr_len_addr != 0)
if (user_put(sockaddr_len_addr, sockaddr_len))
return _EFAULT;
return res;
}
int_t sys_send(fd_t sock_fd, addr_t buf, dword_t len, int_t flags) {
return sys_sendto(sock_fd, buf, len, flags, 0, 0);
}
int_t sys_recv(fd_t sock_fd, addr_t buf, dword_t len, int_t flags) {
return sys_recvfrom(sock_fd, buf, len, flags, 0, 0);
}
int_t sys_shutdown(fd_t sock_fd, dword_t how) {
STRACE("shutdown(%d, %d)", sock_fd, how);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
int err = shutdown(sock->real_fd, how);
if (err < 0)
return errno_map();
return 0;
}
#define DEFAULT_TCP_CONGESTION "cubic"
int_t sys_setsockopt(fd_t sock_fd, dword_t level, dword_t option, addr_t value_addr, dword_t value_len) {
STRACE("setsockopt(%d, %d, %d, 0x%x, %d)", sock_fd, level, option, value_addr, value_len);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
char value[value_len];
if (user_read(value_addr, value, value_len))
return _EFAULT;
// ICMP6_FILTER can only be set on real SOCK_RAW
if (level == IPPROTO_ICMPV6 && option == ICMP6_FILTER_)
return 0;
// IP_MTU_DISCOVER has no equivalent on Darwin
if (level == IPPROTO_IP && option == IP_MTU_DISCOVER_)
return 0;
// TCP_CONGESTION also has no equivalent on Darwin
#if defined(__APPLE__)
if (level == IPPROTO_TCP && option == TCP_CONGESTION_) {
if (strncmp(value, DEFAULT_TCP_CONGESTION, sizeof(value)) == 0)
return 0;
return _ENOENT;
}
#endif
int real_opt = sock_opt_to_real(option, level);
if (real_opt < 0)
return _EINVAL;
int real_level = sock_level_to_real(level);
if (real_level < 0)
return _EINVAL;
// 0 means the option is not implemented, but things rely on it, so we
// should just ignore attempts to set it.
if (real_opt == 0)
return 0;
int err = setsockopt(sock->real_fd, real_level, real_opt, value, value_len);
if (err < 0)
return errno_map();
return 0;
}
int_t sys_getsockopt(fd_t sock_fd, dword_t level, dword_t option, addr_t value_addr, dword_t len_addr) {
STRACE("getsockopt(%d, %d, %d, %#x, %#x)", sock_fd, level, option, value_addr, len_addr);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
dword_t value_len;
if (user_get(len_addr, value_len))
return _EFAULT;
char value[value_len];
if (user_read(value_addr, value, value_len))
return _EFAULT;
if (level == SOL_SOCKET_ && (option == SO_DOMAIN_ || option == SO_TYPE_ || option == SO_PROTOCOL_)) {
dword_t *value_p = (dword_t *) value;
if (value_len != sizeof(*value_p))
return _EINVAL;
if (option == SO_DOMAIN_)
*value_p = sock->socket.domain;
else if (option == SO_TYPE_)
*value_p = sock->socket.type;
else if (option == SO_PROTOCOL_)
*value_p = sock->socket.protocol;
} else if (level == SOL_SOCKET_ && option == SO_PEERCRED_) {
struct ucred_ *cred = (struct ucred_ *) value;
if (value_len != sizeof(*cred))
return _EINVAL;
lock(&peer_lock, 0);
if (sock->socket.domain != AF_LOCAL_ || sock->socket.unix_peer == NULL) {
cred->pid = 0;
cred->uid = cred->gid = -1;
} else {
*cred = sock->socket.unix_peer->socket.unix_cred;
}
unlock(&peer_lock);
} else if (level == SOL_SOCKET_ && option == SO_ERROR_) {
if (value_len != sizeof(dword_t))
return _EINVAL;
int real_error;
socklen_t real_error_len = sizeof(real_error);
int err = getsockopt(sock->real_fd, SOL_SOCKET, SO_ERROR, &real_error, &real_error_len);
if (err < 0)
return errno_map();
*(dword_t *) value = real_error == 0 ? 0 : -err_map(real_error);
} else if (level == IPPROTO_TCP && option == TCP_CONGESTION_) {
value_len = strlen(DEFAULT_TCP_CONGESTION);
memcpy(value, DEFAULT_TCP_CONGESTION, value_len);
#if defined(__APPLE__)
} else if (level == IPPROTO_TCP && option == TCP_INFO_) {
// This one's fun. On Linux, the struct is not ABI dependent, so no
// special handling is needed. On Darwin, the struct is completely
// different and has a different sockopt name.
struct tcp_connection_info conn_info;
socklen_t conn_info_size = sizeof(conn_info);
int err = getsockopt(sock->real_fd, IPPROTO_TCP, TCP_CONNECTION_INFO, &conn_info, &conn_info_size);
if (err < 0)
return errno_map();
// The possible keys for this table are in netinet/tcp_fsm.h, but that
// header isn't available on iOS, only macOS.
static const uint8_t tcp_state_table[] = {
7, // TCPS_CLOSED
10, // TCPS_LISTEN
2, // TCPS_SYN_SENT
3, // TCPS_SYN_RECEIVED
1, // TCPS_ESTABLISHED
8, // TCPS_CLOSE_WAIT
4, // TCPS_FIN_WAIT_1
11, // TCPS_CLOSING
9, // TCPS_LAST_ACK
5, // TCPS_FIN_WAIT_2
6, // TCPS_TIME_WAIT
};
struct tcp_info_ info = {
.state = tcp_state_table[conn_info.tcpi_state],
.options = conn_info.tcpi_options,
.snd_wscale = conn_info.tcpi_snd_wscale,
.rcv_wscale = conn_info.tcpi_rcv_wscale,
.rto = conn_info.tcpi_rto * 1000,
.snd_mss = conn_info.tcpi_maxseg,
.rtt = conn_info.tcpi_srtt * 1000,
.rttvar = conn_info.tcpi_rttvar * 1000,
.snd_ssthresh = conn_info.tcpi_snd_ssthresh,
.snd_cwnd = conn_info.tcpi_snd_cwnd / conn_info.tcpi_maxseg,
// https://lkml.org/lkml/2017/4/24/923
.total_retrans = conn_info.tcpi_txretransmitpackets,
};
if (value_len > sizeof(struct tcp_info_))
value_len = sizeof(struct tcp_info_);
memcpy(value, &info, value_len);
#endif
} else {
int real_opt = sock_opt_to_real(option, level);
if (real_opt < 0)
return _EINVAL;
int real_level = sock_level_to_real(level);
if (real_level < 0)
return _EINVAL;
int err = getsockopt(sock->real_fd, real_level, real_opt, value, &value_len);
if (err < 0)
return errno_map();
}
if (user_put(len_addr, value_len))
return _EFAULT;
if (user_put(value_addr, value))
return _EFAULT;
return 0;
}
static void scm_free(struct scm *scm) {
for (unsigned i = 0; i < scm->num_fds; i++)
fd_close(scm->fds[i]);
free(scm);
}
int_t sys_sendmsg(fd_t sock_fd, addr_t msghdr_addr, int_t flags) {
int err;
STRACE("sendmsg(%d, %#x, %d)", sock_fd, msghdr_addr, flags);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
struct msghdr msg;
struct msghdr_ msg_fake;
if (user_get(msghdr_addr, msg_fake))
return _EFAULT;
// msg_name
struct sockaddr_max_ msg_name;
if (msg_fake.msg_name != 0) {
int err = sockaddr_read(msg_fake.msg_name, &msg_name, &msg_fake.msg_namelen);
if (err < 0)
return err;
msg.msg_name = &msg_name;
msg.msg_namelen = msg_fake.msg_namelen;
} else {
msg.msg_name = NULL;
}
// msg_iovec
struct iovec_ msg_iov_fake[msg_fake.msg_iovlen];
if (user_get(msg_fake.msg_iov, msg_iov_fake))
return _EFAULT;
struct iovec msg_iov[msg_fake.msg_iovlen];
memset(msg_iov, 0, sizeof(msg_iov));
msg.msg_iov = msg_iov;
msg.msg_iovlen = sizeof(msg_iov) / sizeof(msg_iov[0]);
for (size_t i = 0; i < (size_t) msg.msg_iovlen; i++) {
msg_iov[i].iov_len = msg_iov_fake[i].len;
msg_iov[i].iov_base = malloc(msg_iov_fake[i].len);
err = _EFAULT;
if (user_read(msg_iov_fake[i].base, msg_iov[i].iov_base, msg_iov_fake[i].len))
goto out_free_iov;
}
// msg_control
uint8_t msg_control_buf[2048];
uint8_t *msg_control = NULL;
if (msg_fake.msg_control != 0) {
if (msg_fake.msg_controllen > sizeof(msg_control_buf)) {
err = _EINVAL;
goto out_free_iov;
}
msg_control = msg_control_buf;
err = _EFAULT;
if (user_read(msg_fake.msg_control, msg_control, msg_fake.msg_controllen))
goto out_free_iov;
}
msg.msg_control = NULL;
msg.msg_controllen = 0;
struct scm *scm = NULL;
char real_msg_control[CMSG_SPACE(sizeof(int))]; // only used if actually sending an fd
if (sock->socket.domain == AF_LOCAL_ && msg_control != NULL && msg_fake.msg_controllen >= sizeof(struct cmsghdr_)) {
// figure out how many file descriptors we're sending
uint8_t *mhdr_end = msg_control + msg_fake.msg_controllen;
unsigned num_fds = 0;
struct cmsghdr_ *cmsg;
for (cmsg = (void *) msg_control; cmsg != NULL; cmsg = CMSG_NXTHDR_(cmsg, mhdr_end)) {
if (cmsg->level != SOL_SOCKET_)
continue;
if (cmsg->type != SCM_RIGHTS_)
return _EINVAL;
num_fds += (cmsg->len - sizeof(struct cmsghdr_)) / sizeof(fd_t);
}
if (num_fds > 253) // *magic*
return _EINVAL;
if (num_fds > 0) {
// send one (1) real fd and put the rest in a struct scm
static int real_fd = -1;
if (real_fd == -1) {
real_fd = open(".", O_RDONLY);
if (real_fd < 0)
ERRNO_DIE("no");
}
msg.msg_control = real_msg_control;
msg.msg_controllen = sizeof(real_msg_control);
struct cmsghdr *real_cmsg = CMSG_FIRSTHDR(&msg);
real_cmsg->cmsg_level = SOL_SOCKET;
real_cmsg->cmsg_type = SCM_RIGHTS;
real_cmsg->cmsg_len = CMSG_LEN(sizeof(real_fd));
memcpy(CMSG_DATA(real_cmsg), &real_fd, sizeof(real_fd));
scm = malloc(sizeof(struct scm) + num_fds * sizeof(struct fd *));
list_init(&scm->queue);
scm->num_fds = num_fds;
unsigned fd_i = 0;
for (cmsg = (void *) msg_control; cmsg != NULL; cmsg = CMSG_NXTHDR_(cmsg, mhdr_end)) {
if (cmsg->level != SOL_SOCKET_)
continue;
fd_t *fds = (void *) cmsg->data;
for (unsigned i = 0; i < (cmsg->len - sizeof(struct cmsghdr_)) / sizeof(fd_t); i++) {
STRACE(" sending fd %d", fds[i]);
scm->fds[fd_i++] = fd_retain(f_get(fds[i]));
}
}
lock(&peer_lock, 0);
struct fd *peer = sock->socket.unix_peer;
if (peer == NULL) {
unlock(&peer_lock);
err = _EPIPE;
goto out_free_scm;
}
lock(&peer->lock, 0);
list_add_tail(&peer->socket.unix_scm, &scm->queue);
unlock(&peer->lock);
unlock(&peer_lock);
}
}
msg.msg_flags = sock_flags_to_real(msg_fake.msg_flags);
err = _EINVAL;
if (msg.msg_flags < 0)
goto out_free_scm;
int real_flags = sock_flags_to_real(flags);
if (real_flags < 0)
goto out_free_scm;
TASK_MAY_BLOCK {
err = sendmsg(sock->real_fd, &msg, real_flags);
}
if (err < 0) {
err = errno_map();
goto out_free_scm;
}
goto out_free_iov;
out_free_scm:
if (scm != NULL) {
lock(&peer_lock, 0);
struct fd *peer = sock->socket.unix_peer;
if (peer != NULL) {
lock(&peer->lock, 0);
list_remove_safe(&scm->queue);
unlock(&peer->lock);
}
unlock(&peer_lock);
scm_free(scm);
}
out_free_iov:
for (size_t i = 0; i < (size_t) msg.msg_iovlen; i++)
free(msg_iov[i].iov_base);
// if(scm != NULL)
// scm_free(scm);
return err;
}
int_t sys_recvmsg(fd_t sock_fd, addr_t msghdr_addr, int_t flags) {
STRACE("recvmsg(%d, %#x, %d)", sock_fd, msghdr_addr, flags);
struct fd *sock = sock_getfd(sock_fd);
if (sock == NULL)
return _EBADF;
struct msghdr msg;
struct msghdr_ msg_fake;
if (user_get(msghdr_addr, msg_fake))
return _EFAULT;
// msg_name