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qrexec: in write_stdin, remove dependency on write size

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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
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31
qrexec/write_stdin.c
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@ -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, int write_stdin(int fd, int clid, char *data, int len,
struct buffer *buffer) struct buffer *buffer)
{ {
int ret; int ret;
int written = 0;
if (buffer_len(buffer)) { if (buffer_len(buffer)) {
buffer_append(buffer, data, len); buffer_append(buffer, data, len);
return WRITE_STDIN_BUFFERED; return WRITE_STDIN_BUFFERED;
} }
while (written < len) {
ret = write(fd, data, len); ret = write(fd, data + written, len - written);
if (ret == len) if (ret == 0) {
return WRITE_STDIN_OK; perror("write_stdin: write returns 0 ???");
if (ret == -1) { exit(1);
if (errno == EAGAIN) { }
if (ret == -1) {
struct server_header s_hdr; 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.type = MSG_XOFF;
s_hdr.clid = clid; 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); write_all_vchan_ext(&s_hdr, sizeof s_hdr);
return WRITE_STDIN_BUFFERED; return WRITE_STDIN_BUFFERED;
} else }
return WRITE_STDIN_ERROR; written += ret;
} else {
fprintf(stderr,
"writes < PIPE_BUF were supposed to be atomic ?\n");
return WRITE_STDIN_ERROR;
} }
return WRITE_STDIN_OK;
} }