tmux/file.c

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/* $OpenBSD$ */
/*
* Copyright (c) 2019 Nicholas Marriott <nicholas.marriott@gmail.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "tmux.h"
/*
* IPC file handling. Both client and server use the same data structures
* (client_file and client_files) to store list of active files. Most functions
* are for use either in client or server but not both.
*/
static int file_next_stream = 3;
RB_GENERATE(client_files, client_file, entry, file_cmp);
/* Get path for file, either as given or from working directory. */
static char *
file_get_path(struct client *c, const char *file)
{
char *path;
if (*file == '/')
path = xstrdup(file);
else
xasprintf(&path, "%s/%s", server_client_get_cwd(c, NULL), file);
return (path);
}
/* Tree comparison function. */
int
file_cmp(struct client_file *cf1, struct client_file *cf2)
{
if (cf1->stream < cf2->stream)
return (-1);
if (cf1->stream > cf2->stream)
return (1);
return (0);
}
/*
* Create a file object in the client process - the peer is the server to send
* messages to. Check callback is fired when the file is finished with so the
* process can decide if it needs to exit (if it is waiting for files to
* flush).
*/
struct client_file *
file_create_with_peer(struct tmuxpeer *peer, struct client_files *files,
int stream, client_file_cb cb, void *cbdata)
{
struct client_file *cf;
cf = xcalloc(1, sizeof *cf);
cf->c = NULL;
cf->references = 1;
cf->stream = stream;
cf->buffer = evbuffer_new();
if (cf->buffer == NULL)
fatalx("out of memory");
cf->cb = cb;
cf->data = cbdata;
cf->peer = peer;
cf->tree = files;
RB_INSERT(client_files, files, cf);
return (cf);
}
/* Create a file object in the server, communicating with the given client. */
struct client_file *
file_create_with_client(struct client *c, int stream, client_file_cb cb,
void *cbdata)
{
struct client_file *cf;
if (c != NULL && (c->flags & CLIENT_ATTACHED))
c = NULL;
cf = xcalloc(1, sizeof *cf);
cf->c = c;
cf->references = 1;
cf->stream = stream;
cf->buffer = evbuffer_new();
if (cf->buffer == NULL)
fatalx("out of memory");
cf->cb = cb;
cf->data = cbdata;
if (cf->c != NULL) {
cf->peer = cf->c->peer;
cf->tree = &cf->c->files;
RB_INSERT(client_files, &cf->c->files, cf);
cf->c->references++;
}
return (cf);
}
/* Free a file. */
void
file_free(struct client_file *cf)
{
if (--cf->references != 0)
return;
evbuffer_free(cf->buffer);
free(cf->path);
if (cf->tree != NULL)
RB_REMOVE(client_files, cf->tree, cf);
if (cf->c != NULL)
server_client_unref(cf->c);
free(cf);
}
/* Event to fire the done callback. */
static void
file_fire_done_cb(__unused int fd, __unused short events, void *arg)
{
struct client_file *cf = arg;
struct client *c = cf->c;
if (cf->cb != NULL &&
(cf->closed || c == NULL || (~c->flags & CLIENT_DEAD)))
cf->cb(c, cf->path, cf->error, 1, cf->buffer, cf->data);
file_free(cf);
}
/* Add an event to fire the done callback (used by the server). */
void
file_fire_done(struct client_file *cf)
{
event_once(-1, EV_TIMEOUT, file_fire_done_cb, cf, NULL);
}
/* Fire the read callback. */
void
file_fire_read(struct client_file *cf)
{
if (cf->cb != NULL)
cf->cb(cf->c, cf->path, cf->error, 0, cf->buffer, cf->data);
}
/* Can this file be printed to? */
int
file_can_print(struct client *c)
{
if (c == NULL)
return (0);
if (c->session != NULL && (~c->flags & CLIENT_CONTROL))
return (0);
return (1);
}
/* Print a message to a file. */
void
file_print(struct client *c, const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
file_vprint(c, fmt, ap);
va_end(ap);
}
/* Print a message to a file. */
void
file_vprint(struct client *c, const char *fmt, va_list ap)
{
struct client_file find, *cf;
struct msg_write_open msg;
if (!file_can_print(c))
return;
find.stream = 1;
if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) {
cf = file_create_with_client(c, 1, NULL, NULL);
cf->path = xstrdup("-");
evbuffer_add_vprintf(cf->buffer, fmt, ap);
msg.stream = 1;
msg.fd = STDOUT_FILENO;
msg.flags = 0;
proc_send(c->peer, MSG_WRITE_OPEN, -1, &msg, sizeof msg);
} else {
evbuffer_add_vprintf(cf->buffer, fmt, ap);
file_push(cf);
}
}
/* Print a buffer to a file. */
void
file_print_buffer(struct client *c, void *data, size_t size)
{
struct client_file find, *cf;
struct msg_write_open msg;
if (!file_can_print(c))
return;
find.stream = 1;
if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) {
cf = file_create_with_client(c, 1, NULL, NULL);
cf->path = xstrdup("-");
evbuffer_add(cf->buffer, data, size);
msg.stream = 1;
msg.fd = STDOUT_FILENO;
msg.flags = 0;
proc_send(c->peer, MSG_WRITE_OPEN, -1, &msg, sizeof msg);
} else {
evbuffer_add(cf->buffer, data, size);
file_push(cf);
}
}
/* Report an error to a file. */
void
file_error(struct client *c, const char *fmt, ...)
{
struct client_file find, *cf;
struct msg_write_open msg;
va_list ap;
if (!file_can_print(c))
return;
va_start(ap, fmt);
find.stream = 2;
if ((cf = RB_FIND(client_files, &c->files, &find)) == NULL) {
cf = file_create_with_client(c, 2, NULL, NULL);
cf->path = xstrdup("-");
evbuffer_add_vprintf(cf->buffer, fmt, ap);
msg.stream = 2;
msg.fd = STDERR_FILENO;
msg.flags = 0;
proc_send(c->peer, MSG_WRITE_OPEN, -1, &msg, sizeof msg);
} else {
evbuffer_add_vprintf(cf->buffer, fmt, ap);
file_push(cf);
}
va_end(ap);
}
/* Write data to a file. */
void
file_write(struct client *c, const char *path, int flags, const void *bdata,
size_t bsize, client_file_cb cb, void *cbdata)
{
struct client_file *cf;
struct msg_write_open *msg;
size_t msglen;
int fd = -1;
u_int stream = file_next_stream++;
FILE *f;
const char *mode;
if (strcmp(path, "-") == 0) {
cf = file_create_with_client(c, stream, cb, cbdata);
cf->path = xstrdup("-");
fd = STDOUT_FILENO;
if (c == NULL ||
(c->flags & CLIENT_ATTACHED) ||
(c->flags & CLIENT_CONTROL)) {
cf->error = EBADF;
goto done;
}
goto skip;
}
cf = file_create_with_client(c, stream, cb, cbdata);
cf->path = file_get_path(c, path);
if (c == NULL || c->flags & CLIENT_ATTACHED) {
if (flags & O_APPEND)
mode = "ab";
else
mode = "wb";
f = fopen(cf->path, mode);
if (f == NULL) {
cf->error = errno;
goto done;
}
if (fwrite(bdata, 1, bsize, f) != bsize) {
fclose(f);
cf->error = EIO;
goto done;
}
fclose(f);
goto done;
}
skip:
evbuffer_add(cf->buffer, bdata, bsize);
msglen = strlen(cf->path) + 1 + sizeof *msg;
if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
cf->error = E2BIG;
goto done;
}
msg = xmalloc(msglen);
msg->stream = cf->stream;
msg->fd = fd;
msg->flags = flags;
memcpy(msg + 1, cf->path, msglen - sizeof *msg);
if (proc_send(cf->peer, MSG_WRITE_OPEN, -1, msg, msglen) != 0) {
free(msg);
cf->error = EINVAL;
goto done;
}
free(msg);
return;
done:
file_fire_done(cf);
}
/* Read a file. */
struct client_file *
file_read(struct client *c, const char *path, client_file_cb cb, void *cbdata)
{
struct client_file *cf;
struct msg_read_open *msg;
size_t msglen;
int fd = -1;
u_int stream = file_next_stream++;
FILE *f;
size_t size;
char buffer[BUFSIZ];
if (strcmp(path, "-") == 0) {
cf = file_create_with_client(c, stream, cb, cbdata);
cf->path = xstrdup("-");
fd = STDIN_FILENO;
if (c == NULL ||
(c->flags & CLIENT_ATTACHED) ||
(c->flags & CLIENT_CONTROL)) {
cf->error = EBADF;
goto done;
}
goto skip;
}
cf = file_create_with_client(c, stream, cb, cbdata);
cf->path = file_get_path(c, path);
if (c == NULL || c->flags & CLIENT_ATTACHED) {
f = fopen(cf->path, "rb");
if (f == NULL) {
cf->error = errno;
goto done;
}
for (;;) {
size = fread(buffer, 1, sizeof buffer, f);
if (evbuffer_add(cf->buffer, buffer, size) != 0) {
cf->error = ENOMEM;
goto done;
}
if (size != sizeof buffer)
break;
}
if (ferror(f)) {
cf->error = EIO;
goto done;
}
fclose(f);
goto done;
}
skip:
msglen = strlen(cf->path) + 1 + sizeof *msg;
if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE) {
cf->error = E2BIG;
goto done;
}
msg = xmalloc(msglen);
msg->stream = cf->stream;
msg->fd = fd;
memcpy(msg + 1, cf->path, msglen - sizeof *msg);
if (proc_send(cf->peer, MSG_READ_OPEN, -1, msg, msglen) != 0) {
free(msg);
cf->error = EINVAL;
goto done;
}
free(msg);
return cf;
done:
file_fire_done(cf);
return NULL;
}
/* Cancel a file read. */
void
file_cancel(struct client_file *cf)
{
struct msg_read_cancel msg;
log_debug("read cancel file %d", cf->stream);
if (cf->closed)
return;
cf->closed = 1;
msg.stream = cf->stream;
proc_send(cf->peer, MSG_READ_CANCEL, -1, &msg, sizeof msg);
}
/* Push event, fired if there is more writing to be done. */
static void
file_push_cb(__unused int fd, __unused short events, void *arg)
{
struct client_file *cf = arg;
if (cf->c == NULL || ~cf->c->flags & CLIENT_DEAD)
file_push(cf);
file_free(cf);
}
/* Push uwritten data to the client for a file, if it will accept it. */
void
file_push(struct client_file *cf)
{
struct msg_write_data *msg;
size_t msglen, sent, left;
struct msg_write_close close;
msg = xmalloc(sizeof *msg);
left = EVBUFFER_LENGTH(cf->buffer);
while (left != 0) {
sent = left;
if (sent > MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof *msg)
sent = MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof *msg;
msglen = (sizeof *msg) + sent;
msg = xrealloc(msg, msglen);
msg->stream = cf->stream;
memcpy(msg + 1, EVBUFFER_DATA(cf->buffer), sent);
if (proc_send(cf->peer, MSG_WRITE, -1, msg, msglen) != 0)
break;
evbuffer_drain(cf->buffer, sent);
left = EVBUFFER_LENGTH(cf->buffer);
log_debug("file %d sent %zu, left %zu", cf->stream, sent, left);
}
if (left != 0) {
cf->references++;
event_once(-1, EV_TIMEOUT, file_push_cb, cf, NULL);
} else if (cf->stream > 2) {
close.stream = cf->stream;
proc_send(cf->peer, MSG_WRITE_CLOSE, -1, &close, sizeof close);
file_fire_done(cf);
}
free(msg);
}
/* Check if any files have data left to write. */
int
file_write_left(struct client_files *files)
{
struct client_file *cf;
size_t left;
int waiting = 0;
RB_FOREACH(cf, client_files, files) {
if (cf->event == NULL)
continue;
left = EVBUFFER_LENGTH(cf->event->output);
if (left != 0) {
waiting++;
log_debug("file %u %zu bytes left", cf->stream, left);
}
}
return (waiting != 0);
}
/* Client file write error callback. */
static void
file_write_error_callback(__unused struct bufferevent *bev, __unused short what,
void *arg)
{
struct client_file *cf = arg;
log_debug("write error file %d", cf->stream);
bufferevent_free(cf->event);
cf->event = NULL;
close(cf->fd);
cf->fd = -1;
if (cf->cb != NULL)
cf->cb(NULL, NULL, 0, -1, NULL, cf->data);
}
/* Client file write callback. */
static void
file_write_callback(__unused struct bufferevent *bev, void *arg)
{
struct client_file *cf = arg;
log_debug("write check file %d", cf->stream);
if (cf->cb != NULL)
cf->cb(NULL, NULL, 0, -1, NULL, cf->data);
if (cf->closed && EVBUFFER_LENGTH(cf->event->output) == 0) {
bufferevent_free(cf->event);
close(cf->fd);
RB_REMOVE(client_files, cf->tree, cf);
file_free(cf);
}
}
/* Handle a file write open message (client). */
void
file_write_open(struct client_files *files, struct tmuxpeer *peer,
struct imsg *imsg, int allow_streams, int close_received,
client_file_cb cb, void *cbdata)
{
struct msg_write_open *msg = imsg->data;
size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
const char *path;
struct msg_write_ready reply;
struct client_file find, *cf;
const int flags = O_NONBLOCK|O_WRONLY|O_CREAT;
int error = 0;
if (msglen < sizeof *msg)
fatalx("bad MSG_WRITE_OPEN size");
if (msglen == sizeof *msg)
path = "-";
else
path = (const char *)(msg + 1);
log_debug("open write file %d %s", msg->stream, path);
find.stream = msg->stream;
if (RB_FIND(client_files, files, &find) != NULL) {
error = EBADF;
goto reply;
}
cf = file_create_with_peer(peer, files, msg->stream, cb, cbdata);
if (cf->closed) {
error = EBADF;
goto reply;
}
cf->fd = -1;
if (msg->fd == -1)
cf->fd = open(path, msg->flags|flags, 0644);
else if (allow_streams) {
if (msg->fd != STDOUT_FILENO && msg->fd != STDERR_FILENO)
errno = EBADF;
else {
cf->fd = dup(msg->fd);
if (close_received)
close(msg->fd); /* can only be used once */
}
} else
errno = EBADF;
if (cf->fd == -1) {
error = errno;
goto reply;
}
cf->event = bufferevent_new(cf->fd, NULL, file_write_callback,
file_write_error_callback, cf);
if (cf->event == NULL)
fatalx("out of memory");
bufferevent_enable(cf->event, EV_WRITE);
goto reply;
reply:
reply.stream = msg->stream;
reply.error = error;
proc_send(peer, MSG_WRITE_READY, -1, &reply, sizeof reply);
}
/* Handle a file write data message (client). */
void
file_write_data(struct client_files *files, struct imsg *imsg)
{
struct msg_write_data *msg = imsg->data;
size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
struct client_file find, *cf;
size_t size = msglen - sizeof *msg;
if (msglen < sizeof *msg)
fatalx("bad MSG_WRITE size");
find.stream = msg->stream;
if ((cf = RB_FIND(client_files, files, &find)) == NULL)
fatalx("unknown stream number");
log_debug("write %zu to file %d", size, cf->stream);
if (cf->event != NULL)
bufferevent_write(cf->event, msg + 1, size);
}
/* Handle a file write close message (client). */
void
file_write_close(struct client_files *files, struct imsg *imsg)
{
struct msg_write_close *msg = imsg->data;
size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
struct client_file find, *cf;
if (msglen != sizeof *msg)
fatalx("bad MSG_WRITE_CLOSE size");
find.stream = msg->stream;
if ((cf = RB_FIND(client_files, files, &find)) == NULL)
fatalx("unknown stream number");
log_debug("close file %d", cf->stream);
if (cf->event == NULL || EVBUFFER_LENGTH(cf->event->output) == 0) {
if (cf->event != NULL)
bufferevent_free(cf->event);
if (cf->fd != -1)
close(cf->fd);
RB_REMOVE(client_files, files, cf);
file_free(cf);
}
}
/* Client file read error callback. */
static void
file_read_error_callback(__unused struct bufferevent *bev, __unused short what,
void *arg)
{
struct client_file *cf = arg;
struct msg_read_done msg;
log_debug("read error file %d", cf->stream);
msg.stream = cf->stream;
msg.error = 0;
proc_send(cf->peer, MSG_READ_DONE, -1, &msg, sizeof msg);
bufferevent_free(cf->event);
close(cf->fd);
RB_REMOVE(client_files, cf->tree, cf);
file_free(cf);
}
/* Client file read callback. */
static void
file_read_callback(__unused struct bufferevent *bev, void *arg)
{
struct client_file *cf = arg;
void *bdata;
size_t bsize;
struct msg_read_data *msg;
size_t msglen;
msg = xmalloc(sizeof *msg);
for (;;) {
bdata = EVBUFFER_DATA(cf->event->input);
bsize = EVBUFFER_LENGTH(cf->event->input);
if (bsize == 0)
break;
if (bsize > MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof *msg)
bsize = MAX_IMSGSIZE - IMSG_HEADER_SIZE - sizeof *msg;
log_debug("read %zu from file %d", bsize, cf->stream);
msglen = (sizeof *msg) + bsize;
msg = xrealloc(msg, msglen);
msg->stream = cf->stream;
memcpy(msg + 1, bdata, bsize);
proc_send(cf->peer, MSG_READ, -1, msg, msglen);
evbuffer_drain(cf->event->input, bsize);
}
free(msg);
}
/* Handle a file read open message (client). */
void
file_read_open(struct client_files *files, struct tmuxpeer *peer,
struct imsg *imsg, int allow_streams, int close_received, client_file_cb cb,
void *cbdata)
{
struct msg_read_open *msg = imsg->data;
size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
const char *path;
struct msg_read_done reply;
struct client_file find, *cf;
const int flags = O_NONBLOCK|O_RDONLY;
int error;
if (msglen < sizeof *msg)
fatalx("bad MSG_READ_OPEN size");
if (msglen == sizeof *msg)
path = "-";
else
path = (const char *)(msg + 1);
log_debug("open read file %d %s", msg->stream, path);
find.stream = msg->stream;
if (RB_FIND(client_files, files, &find) != NULL) {
error = EBADF;
goto reply;
}
cf = file_create_with_peer(peer, files, msg->stream, cb, cbdata);
if (cf->closed) {
error = EBADF;
goto reply;
}
cf->fd = -1;
if (msg->fd == -1)
cf->fd = open(path, flags);
else if (allow_streams) {
if (msg->fd != STDIN_FILENO)
errno = EBADF;
else {
cf->fd = dup(msg->fd);
if (close_received)
close(msg->fd); /* can only be used once */
}
} else
errno = EBADF;
if (cf->fd == -1) {
error = errno;
goto reply;
}
cf->event = bufferevent_new(cf->fd, file_read_callback, NULL,
file_read_error_callback, cf);
if (cf->event == NULL)
fatalx("out of memory");
bufferevent_enable(cf->event, EV_READ);
return;
reply:
reply.stream = msg->stream;
reply.error = error;
proc_send(peer, MSG_READ_DONE, -1, &reply, sizeof reply);
}
/* Handle a read cancel message (client). */
void
file_read_cancel(struct client_files *files, struct imsg *imsg)
{
struct msg_read_cancel *msg = imsg->data;
size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
struct client_file find, *cf;
if (msglen != sizeof *msg)
fatalx("bad MSG_READ_CANCEL size");
find.stream = msg->stream;
if ((cf = RB_FIND(client_files, files, &find)) == NULL)
fatalx("unknown stream number");
log_debug("cancel file %d", cf->stream);
file_read_error_callback(NULL, 0, cf);
}
/* Handle a write ready message (server). */
void
file_write_ready(struct client_files *files, struct imsg *imsg)
{
struct msg_write_ready *msg = imsg->data;
size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
struct client_file find, *cf;
if (msglen != sizeof *msg)
fatalx("bad MSG_WRITE_READY size");
find.stream = msg->stream;
if ((cf = RB_FIND(client_files, files, &find)) == NULL)
return;
if (msg->error != 0) {
cf->error = msg->error;
file_fire_done(cf);
} else
file_push(cf);
}
/* Handle read data message (server). */
void
file_read_data(struct client_files *files, struct imsg *imsg)
{
struct msg_read_data *msg = imsg->data;
size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
struct client_file find, *cf;
void *bdata = msg + 1;
size_t bsize = msglen - sizeof *msg;
if (msglen < sizeof *msg)
fatalx("bad MSG_READ_DATA size");
find.stream = msg->stream;
if ((cf = RB_FIND(client_files, files, &find)) == NULL)
return;
log_debug("file %d read %zu bytes", cf->stream, bsize);
if (cf->error == 0 && !cf->closed) {
if (evbuffer_add(cf->buffer, bdata, bsize) != 0) {
cf->error = ENOMEM;
file_fire_done(cf);
} else
file_fire_read(cf);
}
}
/* Handle a read done message (server). */
void
file_read_done(struct client_files *files, struct imsg *imsg)
{
struct msg_read_done *msg = imsg->data;
size_t msglen = imsg->hdr.len - IMSG_HEADER_SIZE;
struct client_file find, *cf;
if (msglen != sizeof *msg)
fatalx("bad MSG_READ_DONE size");
find.stream = msg->stream;
if ((cf = RB_FIND(client_files, files, &find)) == NULL)
return;
log_debug("file %d read done", cf->stream);
cf->error = msg->error;
file_fire_done(cf);
}