kenmirrors/asterisk
1
0
Fork 0
mirror of https://github.com/asterisk/asterisk.git synced 2025-09-19 19:52:48 +00:00
Code Issues Packages Projects Releases Wiki Activity

Introduce ast_careful_fwrite() and use in AMI to prevent partial writes.

Browse Source 
This patch introduces a function to do careful writes on a file stream which
will handle timeouts and partial writes.  It is currently used in AMI to
address the issue that has been reported.  However, there are probably a few
other places where this could be used.

(closes issue #13546)
Reported by: srt
Tested by: russell
http://reviewboard.digium.com/r/104/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@166282 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Russell Bryant
2008-12-22 17:09:36 +00:00
parent 77b1fe0ceb
commit c2999a8366
3 changed files with 110 additions and 48 deletions
Download Patch File Download Diff File Expand all files Collapse all files

114
main/utils.c
View File

@@ -1057,6 +1057,38 @@ int ast_wait_for_input(int fd, int ms)
return poll(pfd, 1, ms);
}
static int ast_wait_for_output(int fd, int timeoutms)
{
struct pollfd pfd = {
.fd = fd,
.events = POLLOUT,
};
int res;
/* poll() until the fd is writable without blocking */
while ((res = poll(&pfd, 1, timeoutms)) <= 0) {
if (res == 0) {
/* timed out. */
ast_log(LOG_NOTICE, "Timed out trying to write\n");
return -1;
} else if (res == -1) {
/* poll() returned an error, check to see if it was fatal */
if (errno == EINTR || errno == EAGAIN) {
/* This was an acceptable error, go back into poll() */
continue;
}
/* Fatal error, bail. */
ast_log(LOG_ERROR, "poll returned error: %s\n", strerror(errno));
return -1;
}
}
return 0;
}
/*!
* Try to write string, but wait no more than ms milliseconds before timing out.
*
@@ -1077,30 +1109,8 @@ int ast_carefulwrite(int fd, char *s, int len, int timeoutms)
int res = 0;
while (len) {
struct pollfd pfd = {
.fd = fd,
.events = POLLOUT,
};
/* poll() until the fd is writable without blocking */
while ((res = poll(&pfd, 1, timeoutms)) <= 0) {
if (res == 0) {
/* timed out. */
ast_log(LOG_NOTICE, "Timed out trying to write\n");
return -1;
} else if (res == -1) {
/* poll() returned an error, check to see if it was fatal */
if (errno == EINTR || errno == EAGAIN) {
/* This was an acceptable error, go back into poll() */
continue;
}
/* Fatal error, bail. */
ast_log(LOG_ERROR, "poll returned error: %s\n", strerror(errno));
return -1;
}
if (ast_wait_for_output(fd, timeoutms)) {
return -1;
}
res = write(fd, s, len);
@@ -1125,6 +1135,62 @@ int ast_carefulwrite(int fd, char *s, int len, int timeoutms)
return res;
}
int ast_careful_fwrite(FILE *f, int fd, const char *src, size_t len, int timeoutms)
{
struct timeval start = ast_tvnow();
int n = 0;
while (len) {
int elapsed;
if (ast_wait_for_output(fd, timeoutms)) {
/* poll returned a fatal error, so bail out immediately. */
return -1;
}
/* Clear any errors from a previous write */
clearerr(f);
n = fwrite(src, 1, len, f);
if (ferror(f) && errno != EINTR && errno != EAGAIN) {
/* fatal error from fwrite() */
if (!feof(f)) {
/* Don't spam the logs if it was just that the connection is closed. */
ast_log(LOG_ERROR, "fwrite() returned error: %s\n", strerror(errno));
}
n = -1;
break;
}
/* Update for data already written to the socket */
len -= n;
src += n;
elapsed = ast_tvdiff_ms(ast_tvnow(), start);
if (elapsed > timeoutms) {
/* We've taken too long to write
* This is only an error condition if we haven't finished writing. */
n = len ? -1 : 0;
break;
}
}
while (fflush(f)) {
if (errno == EAGAIN || errno == EINTR) {
continue;
}
if (!feof(f)) {
/* Don't spam the logs if it was just that the connection is closed. */
ast_log(LOG_ERROR, "fflush() returned error: %s\n", strerror(errno));
}
n = -1;
break;
}
return n < 0 ? -1 : 0;
}
char *ast_strip_quoted(char *s, const char *beg_quotes, const char *end_quotes)
{
char *e;