Qubes/core-admin
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

qrexec: in write_stdin, remove dependency on write size

Browse Source 
Previous code could barf when write was partial; probably can happen
only if we increase vchan buffer size, but it is better isolated now.
This commit is contained in:
Rafal Wojtczuk 2011-03-18 11:16:05 +01:00
parent 1d24ef9d1a
commit 7f6a06c354
1 changed files with 17 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
qrexec/write_stdin.c
View File

@ -58,24 +58,30 @@ int flush_client_data(int fd, int clid, struct buffer *buffer)
}
int write_stdin(int fd, int clid, char *data, int len,
struct buffer *buffer)
{
int ret;
int written = 0;
if (buffer_len(buffer)) {
buffer_append(buffer, data, len);
return WRITE_STDIN_BUFFERED;
}
ret = write(fd, data, len);
if (ret == len)
return WRITE_STDIN_OK;
if (ret == -1) {
if (errno == EAGAIN) {
while (written < len) {
ret = write(fd, data + written, len - written);
if (ret == 0) {
perror("write_stdin: write returns 0 ???");
exit(1);
}
if (ret == -1) {
struct server_header s_hdr;
buffer_append(buffer, data, len);
if (errno != EAGAIN)
return WRITE_STDIN_ERROR;
buffer_append(buffer, data + written,
len - written);
s_hdr.type = MSG_XOFF;
s_hdr.clid = clid;
@ -83,13 +89,10 @@ int write_stdin(int fd, int clid, char *data, int len,
write_all_vchan_ext(&s_hdr, sizeof s_hdr);
return WRITE_STDIN_BUFFERED;
} else
return WRITE_STDIN_ERROR;
} else {
fprintf(stderr,
"writes < PIPE_BUF were supposed to be atomic ?\n");
return WRITE_STDIN_ERROR;
}
written += ret;
}
return WRITE_STDIN_OK;
}