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Break up io_callback() into read_callback() and write_callback()

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to make it clear that we can't get an event with both read and write
set.
This commit is contained in:
Todd C. Miller
2016-05-09 10:53:20 -06:00
parent 094854adfe
commit b04c49dbd3
1 changed files with 115 additions and 108 deletions
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155
src/exec_pty.c
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@@ -537,85 +537,16 @@ terminate_command(pid_t pid, bool use_pgrp)
} }
/* /*
* Read/write an iobuf that is ready. * Read an iobuf that is ready.
*/ */
static void static void
io_callback(int fd, int what, void *v) read_callback(int fd, int what, void *v)
{ {
struct io_buffer *iob = v; struct io_buffer *iob = v;
struct sudo_event_base *evbase; struct sudo_event_base *evbase;
int n; int n;
debug_decl(io_callback, SUDO_DEBUG_EXEC); debug_decl(read_callback, SUDO_DEBUG_EXEC);
if (ISSET(what, SUDO_EV_WRITE)) {
evbase = sudo_ev_get_base(iob->wevent);
do {
n = write(fd, iob->buf + iob->off, iob->len - iob->off);
} while (n == -1 && errno == EINTR);
if (n == -1) {
switch (errno) {
case EPIPE:
case ENXIO:
case EIO:
case EBADF:
/* other end of pipe closed or pty revoked */
sudo_debug_printf(SUDO_DEBUG_INFO,
"unable to write %d bytes to fd %d",
iob->len - iob->off, fd);
/* Close reader if there is one. */
if (iob->revent != NULL) {
safe_close(sudo_ev_get_fd(iob->revent));
ev_free_by_fd(evbase, sudo_ev_get_fd(iob->revent));
}
CLR(what, SUDO_EV_READ);
safe_close(fd);
ev_free_by_fd(evbase, fd);
break;
case EAGAIN:
/* not an error */
break;
default:
#if 0 /* XXX -- how to set cstat? stash in iobufs instead? */
if (cstat != NULL) {
cstat->type = CMD_ERRNO;
cstat->val = errno;
}
#endif /* XXX */
sudo_debug_printf(SUDO_DEBUG_ERROR,
"error writing fd %d: %s", fd, strerror(errno));
sudo_ev_loopbreak(evbase);
break;
}
} else {
sudo_debug_printf(SUDO_DEBUG_INFO,
"wrote %d bytes to fd %d", n, fd);
iob->off += n;
/* Reset buffer if fully consumed. */
if (iob->off == iob->len) {
iob->off = iob->len = 0;
/* Forward the EOF from reader to writer. */
if (iob->revent == NULL) {
CLR(what, SUDO_EV_READ);
safe_close(fd);
ev_free_by_fd(evbase, fd);
}
}
/* Re-enable writer if buffer is not empty. */
if (iob->len > iob->off) {
if (sudo_ev_add(evbase, iob->wevent, NULL, false) == -1)
sudo_fatal(U_("unable to add event to queue"));
}
/* Enable reader if buffer is not full. */
if (iob->revent != NULL &&
(ttymode == TERM_RAW || !USERTTY_EVENT(iob->revent))) {
if (iob->len != sizeof(iob->buf)) {
if (sudo_ev_add(evbase, iob->revent, NULL, false) == -1)
sudo_fatal(U_("unable to add event to queue"));
}
}
}
}
if (ISSET(what, SUDO_EV_READ)) {
evbase = sudo_ev_get_base(iob->revent); evbase = sudo_ev_get_base(iob->revent);
do { do {
n = read(fd, iob->buf + iob->len, sizeof(iob->buf) - iob->len); n = read(fd, iob->buf + iob->len, sizeof(iob->buf) - iob->len);
@@ -663,6 +594,82 @@ io_callback(int fd, int what, void *v)
break; break;
} }
} }
/*
* Write an iobuf that is ready.
*/
static void
write_callback(int fd, int what, void *v)
{
struct io_buffer *iob = v;
struct sudo_event_base *evbase;
int n;
debug_decl(write_callback, SUDO_DEBUG_EXEC);
evbase = sudo_ev_get_base(iob->wevent);
do {
n = write(fd, iob->buf + iob->off, iob->len - iob->off);
} while (n == -1 && errno == EINTR);
if (n == -1) {
switch (errno) {
case EPIPE:
case ENXIO:
case EIO:
case EBADF:
/* other end of pipe closed or pty revoked */
sudo_debug_printf(SUDO_DEBUG_INFO,
"unable to write %d bytes to fd %d",
iob->len - iob->off, fd);
/* Close reader if there is one. */
if (iob->revent != NULL) {
safe_close(sudo_ev_get_fd(iob->revent));
ev_free_by_fd(evbase, sudo_ev_get_fd(iob->revent));
}
safe_close(fd);
ev_free_by_fd(evbase, fd);
break;
case EAGAIN:
/* not an error */
break;
default:
#if 0 /* XXX -- how to set cstat? stash in iobufs instead? */
if (cstat != NULL) {
cstat->type = CMD_ERRNO;
cstat->val = errno;
}
#endif /* XXX */
sudo_debug_printf(SUDO_DEBUG_ERROR,
"error writing fd %d: %s", fd, strerror(errno));
sudo_ev_loopbreak(evbase);
break;
}
} else {
sudo_debug_printf(SUDO_DEBUG_INFO,
"wrote %d bytes to fd %d", n, fd);
iob->off += n;
/* Reset buffer if fully consumed. */
if (iob->off == iob->len) {
iob->off = iob->len = 0;
/* Forward the EOF from reader to writer. */
if (iob->revent == NULL) {
safe_close(fd);
ev_free_by_fd(evbase, fd);
}
}
/* Re-enable writer if buffer is not empty. */
if (iob->len > iob->off) {
if (sudo_ev_add(evbase, iob->wevent, NULL, false) == -1)
sudo_fatal(U_("unable to add event to queue"));
}
/* Enable reader if buffer is not full. */
if (iob->revent != NULL &&
(ttymode == TERM_RAW || !USERTTY_EVENT(iob->revent))) {
if (iob->len != sizeof(iob->buf)) {
if (sudo_ev_add(evbase, iob->revent, NULL, false) == -1)
sudo_fatal(U_("unable to add event to queue"));
}
}
}
} }
static void static void
@@ -684,8 +691,8 @@ io_buf_new(int rfd, int wfd, bool (*action)(const char *, unsigned int, struct i
/* Allocate and add to head of list. */ /* Allocate and add to head of list. */
if ((iob = malloc(sizeof(*iob))) == NULL) if ((iob = malloc(sizeof(*iob))) == NULL)
sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory")); sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
iob->revent = sudo_ev_alloc(rfd, SUDO_EV_READ, io_callback, iob); iob->revent = sudo_ev_alloc(rfd, SUDO_EV_READ, read_callback, iob);
iob->wevent = sudo_ev_alloc(wfd, SUDO_EV_WRITE, io_callback, iob); iob->wevent = sudo_ev_alloc(wfd, SUDO_EV_WRITE, write_callback, iob);
iob->len = 0; iob->len = 0;
iob->off = 0; iob->off = 0;
iob->action = action; iob->action = action;