svn commit: trunk/busybox/networking
vda at busybox.net
vda at busybox.net
Sun Sep 23 13:56:58 UTC 2007
Author: vda
Date: 2007-09-23 06:56:57 -0700 (Sun, 23 Sep 2007)
New Revision: 19967
Log:
httpd: simplify CGI i/o loop. -200 bytes.
Modified:
trunk/busybox/networking/httpd.c
Changeset:
Modified: trunk/busybox/networking/httpd.c
===================================================================
--- trunk/busybox/networking/httpd.c 2007-09-23 12:12:22 UTC (rev 19966)
+++ trunk/busybox/networking/httpd.c 2007-09-23 13:56:57 UTC (rev 19967)
@@ -104,13 +104,16 @@
//#define DEBUG 1
#define DEBUG 0
+#define IOBUF_SIZE 8192 /* IO buffer */
+
/* amount of buffering in a pipe */
#ifndef PIPE_BUF
# define PIPE_BUF 4096
#endif
+#if PIPE_BUF >= IOBUF_SIZE
+# error "PIPE_BUF >= IOBUF_SIZE"
+#endif
-#define IOBUF_SIZE 8192 /* IO buffer */
-
#define HEADER_READ_TIMEOUT 60
static const char default_path_httpd_conf[] ALIGN1 = "/etc";
@@ -1029,6 +1032,173 @@
}
#if ENABLE_FEATURE_HTTPD_CGI
+
+/* gcc 4.2.1 fares better with NOINLINE */
+static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len) ATTRIBUTE_NORETURN;
+static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post_len)
+{
+ enum { FROM_CGI = 1, TO_CGI = 2 }; /* indexes in pfd[] */
+ struct pollfd pfd[3];
+ int out_cnt; /* we buffer a bit of initial CGI output */
+ int count;
+
+ /* iobuf is used for CGI -> network data,
+ * hdr_buf is for network -> CGI data (POSTDATA) */
+
+ /* If CGI dies, we still want to correctly finish reading its output
+ * and send it to the peer. So please no SIGPIPEs! */
+ signal(SIGPIPE, SIG_IGN);
+
+ /* NB: breaking out of this loop jumps to log_and_exit() */
+ out_cnt = 0;
+ while (1) {
+ memset(pfd, 0, sizeof(pfd));
+
+ pfd[FROM_CGI].fd = fromCgi_rd;
+ pfd[FROM_CGI].events = POLLIN;
+
+ if (toCgi_wr) {
+ pfd[TO_CGI].fd = toCgi_wr;
+ if (hdr_cnt > 0) {
+ pfd[TO_CGI].events = POLLOUT;
+ } else if (post_len > 0) {
+ pfd[0].events = POLLIN;
+ } else {
+ /* post_len <= 0 && hdr_cnt <= 0:
+ * no more POST data to CGI,
+ * let CGI see EOF on CGI's stdin */
+ close(toCgi_wr);
+ toCgi_wr = 0;
+ }
+ }
+
+ /* Now wait on the set of sockets */
+ count = poll(pfd, 3, -1);
+ if (count <= 0) {
+#if 0
+ if (errno == EINTR)
+ continue;
+#endif
+#if 0
+ if (waitpid(pid, &status, WNOHANG) <= 0) {
+ /* Weird. CGI didn't exit and no fd's
+ * are ready, yet poll returned?! */
+ continue;
+ }
+ if (DEBUG && WIFEXITED(status))
+ bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
+ if (DEBUG && WIFSIGNALED(status))
+ bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
+#endif
+ break;
+ }
+
+ if (pfd[TO_CGI].revents) {
+ /* hdr_cnt > 0 here due to the way pfd[TO_CGI].events set */
+ /* Have data from peer and can write to CGI */
+ count = safe_write(toCgi_wr, hdr_ptr, hdr_cnt);
+ /* Doesn't happen, we dont use nonblocking IO here
+ *if (count < 0 && errno == EAGAIN) {
+ * ...
+ *} else */
+ if (count > 0) {
+ hdr_ptr += count;
+ hdr_cnt -= count;
+ } else {
+ /* EOF/broken pipe to CGI, stop piping POST data */
+ hdr_cnt = post_len = 0;
+ }
+ }
+
+ if (pfd[0].revents) {
+ /* post_len > 0 && hdr_cnt == 0 here */
+ /* We expect data, prev data portion is eaten by CGI
+ * and there *is* data to read from the peer
+ * (POSTDATA) */
+ //count = post_len > (int)sizeof(hdr_buf) ? (int)sizeof(hdr_buf) : post_len;
+ //count = safe_read(0, hdr_buf, count);
+ count = safe_read(0, hdr_buf, sizeof(hdr_buf));
+ if (count > 0) {
+ hdr_cnt = count;
+ hdr_ptr = hdr_buf;
+ post_len -= count;
+ } else {
+ /* no more POST data can be read */
+ post_len = 0;
+ }
+ }
+
+ if (pfd[FROM_CGI].revents) {
+ /* There is something to read from CGI */
+ char *rbuf = iobuf;
+
+ /* Are we still buffering CGI output? */
+ if (out_cnt >= 0) {
+ /* HTTP_200[] has single "\r\n" at the end.
+ * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
+ * CGI scripts MUST send their own header terminated by
+ * empty line, then data. That's why we have only one
+ * <cr><lf> pair here. We will output "200 OK" line
+ * if needed, but CGI still has to provide blank line
+ * between header and body */
+
+ /* Must use safe_read, not full_read, because
+ * CGI may output a few first bytes and then wait
+ * for POSTDATA without closing stdout.
+ * With full_read we may wait here forever. */
+ count = safe_read(fromCgi_rd, rbuf + out_cnt, PIPE_BUF - 8);
+ if (count <= 0) {
+ /* eof (or error) and there was no "HTTP",
+ * so write it, then write received data */
+ if (out_cnt) {
+ full_write(1, HTTP_200, sizeof(HTTP_200)-1);
+ full_write(1, rbuf, out_cnt);
+ }
+ break; /* CGI stdout is closed, exiting */
+ }
+ out_cnt += count;
+ count = 0;
+ /* "Status" header format is: "Status: 302 Redirected\r\n" */
+ if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
+ /* send "HTTP/1.0 " */
+ if (full_write(1, HTTP_200, 9) != 9)
+ break;
+ rbuf += 8; /* skip "Status: " */
+ count = out_cnt - 8;
+ out_cnt = -1; /* buffering off */
+ } else if (out_cnt >= 4) {
+ /* Did CGI add "HTTP"? */
+ if (memcmp(rbuf, HTTP_200, 4) != 0) {
+ /* there is no "HTTP", do it ourself */
+ if (full_write(1, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
+ break;
+ }
+ /* Commented out:
+ if (!strstr(rbuf, "ontent-")) {
+ full_write(s, "Content-type: text/plain\r\n\r\n", 28);
+ }
+ * Counter-example of valid CGI without Content-type:
+ * echo -en "HTTP/1.0 302 Found\r\n"
+ * echo -en "Location: http://www.busybox.net\r\n"
+ * echo -en "\r\n"
+ */
+ count = out_cnt;
+ out_cnt = -1; /* buffering off */
+ }
+ } else {
+ count = safe_read(fromCgi_rd, rbuf, PIPE_BUF);
+ if (count <= 0)
+ break; /* eof (or error) */
+ }
+ if (full_write(1, rbuf, count) != count)
+ break;
+ if (DEBUG)
+ fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
+ } /* if (pfd[FROM_CGI].revents) */
+ } /* while (1) */
+ log_and_exit();
+}
+
static void setenv1(const char *name, const char *value)
{
setenv(name, value ? value : "", 1);
@@ -1038,25 +1208,25 @@
* Spawn CGI script, forward CGI's stdin/out <=> network
*
* Environment variables are set up and the script is invoked with pipes
- * for stdin/stdout. If a post is being done the script is fed the POST
+ * for stdin/stdout. If a POST is being done the script is fed the POST
* data in addition to setting the QUERY_STRING variable (for GETs or POSTs).
*
* Parameters:
* const char *url The requested URL (with leading /).
- * int bodyLen Length of the post body.
+ * int post_len Length of the POST body.
* const char *cookie For set HTTP_COOKIE.
* const char *content_type For set CONTENT_TYPE.
*/
static void send_cgi_and_exit(
const char *url,
const char *request,
- int bodyLen,
+ int post_len,
const char *cookie,
const char *content_type) ATTRIBUTE_NORETURN;
static void send_cgi_and_exit(
const char *url,
const char *request,
- int bodyLen,
+ int post_len,
const char *cookie,
const char *content_type)
{
@@ -1065,9 +1235,7 @@
char *fullpath;
char *script;
char *purl;
- int buf_count;
- int status;
- int pid = 0;
+ int pid;
/*
* We are mucking with environment _first_ and then vfork/exec,
@@ -1138,8 +1306,8 @@
}
}
setenv1("HTTP_USER_AGENT", user_agent);
- if (bodyLen)
- putenv(xasprintf("CONTENT_LENGTH=%d", bodyLen));
+ if (post_len)
+ putenv(xasprintf("CONTENT_LENGTH=%d", post_len));
if (cookie)
setenv1("HTTP_COOKIE", cookie);
if (content_type)
@@ -1215,168 +1383,15 @@
/* Parent process */
- /* First, restore variables possibly changed by child */
+ /* Restore variables possibly changed by child */
xfunc_error_retval = 0;
- /* Prepare for pumping data.
- * iobuf is used for CGI -> network data,
- * hdr_buf is for network -> CGI data (POSTDATA) */
- buf_count = 0;
+ /* Pump data */
close(fromCgi.wr);
close(toCgi.rd);
+ cgi_io_loop_and_exit(fromCgi.rd, toCgi.wr, post_len);
+}
- /* If CGI dies, we still want to correctly finish reading its output
- * and send it to the peer. So please no SIGPIPEs! */
- signal(SIGPIPE, SIG_IGN);
-
- /* This loop still looks messy. What is an exit criteria?
- * "CGI's output closed"? Or "CGI has exited"?
- * What to do if CGI has closed both input and output, but
- * didn't exit? etc... */
-
- /* NB: breaking out of this loop jumps to log_and_exit() */
- while (1) {
- fd_set readSet;
- fd_set writeSet;
- int nfound;
- int count;
-
- FD_ZERO(&readSet);
- FD_ZERO(&writeSet);
- FD_SET(fromCgi.rd, &readSet);
- if (bodyLen > 0 || hdr_cnt > 0) {
- FD_SET(toCgi.wr, &writeSet);
- nfound = toCgi.wr > fromCgi.rd ? toCgi.wr : fromCgi.rd;
- if (hdr_cnt <= 0)
- FD_SET(0, &readSet);
- /* Now wait on the set of sockets! */
- nfound = select(nfound + 1, &readSet, &writeSet, NULL, NULL);
- } else {
- if (!bodyLen) {
- close(toCgi.wr); /* no more POST data to CGI */
- bodyLen = -1;
- }
- nfound = select(fromCgi.rd + 1, &readSet, NULL, NULL, NULL);
- }
-
- if (nfound <= 0) {
- if (waitpid(pid, &status, WNOHANG) <= 0) {
- /* Weird. CGI didn't exit and no fd's
- * are ready, yet select returned?! */
- continue;
- }
- close(fromCgi.rd);
- if (DEBUG && WIFEXITED(status))
- bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
- if (DEBUG && WIFSIGNALED(status))
- bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
- break;
- }
-
- if (hdr_cnt > 0 && FD_ISSET(toCgi.wr, &writeSet)) {
- /* Have data from peer and can write to CGI */
- count = safe_write(toCgi.wr, hdr_ptr, hdr_cnt);
- /* Doesn't happen, we dont use nonblocking IO here
- *if (count < 0 && errno == EAGAIN) {
- * ...
- *} else */
- if (count > 0) {
- hdr_ptr += count;
- hdr_cnt -= count;
- } else {
- hdr_cnt = bodyLen = 0; /* EOF/broken pipe to CGI */
- }
- } else if (bodyLen > 0 && hdr_cnt == 0
- && FD_ISSET(0, &readSet)
- ) {
- /* We expect data, prev data portion is eaten by CGI
- * and there *is* data to read from the peer
- * (POSTDATA?) */
- count = bodyLen > (int)sizeof(hdr_buf) ? (int)sizeof(hdr_buf) : bodyLen;
- count = safe_read(0, hdr_buf, count);
- if (count > 0) {
- hdr_cnt = count;
- hdr_ptr = hdr_buf;
- bodyLen -= count;
- } else {
- bodyLen = 0; /* closed */
- }
- }
-
-#define PIPESIZE PIPE_BUF
-#if PIPESIZE >= IOBUF_SIZE
-# error "PIPESIZE >= IOBUF_SIZE"
-#endif
- if (FD_ISSET(fromCgi.rd, &readSet)) {
- /* There is something to read from CGI */
- char *rbuf = iobuf;
-
- /* Are we still buffering CGI output? */
- if (buf_count >= 0) {
- /* HTTP_200[] has single "\r\n" at the end.
- * According to http://hoohoo.ncsa.uiuc.edu/cgi/out.html,
- * CGI scripts MUST send their own header terminated by
- * empty line, then data. That's why we have only one
- * <cr><lf> pair here. We will output "200 OK" line
- * if needed, but CGI still has to provide blank line
- * between header and body */
-
- /* Must use safe_read, not full_read, because
- * CGI may output a few first bytes and then wait
- * for POSTDATA without closing stdout.
- * With full_read we may wait here forever. */
- count = safe_read(fromCgi.rd, rbuf + buf_count, PIPESIZE - 8);
- if (count <= 0) {
- /* eof (or error) and there was no "HTTP",
- * so write it, then write received data */
- if (buf_count) {
- full_write(1, HTTP_200, sizeof(HTTP_200)-1);
- full_write(1, rbuf, buf_count);
- }
- break; /* CGI stdout is closed, exiting */
- }
- buf_count += count;
- count = 0;
- /* "Status" header format is: "Status: 302 Redirected\r\n" */
- if (buf_count >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
- /* send "HTTP/1.0 " */
- if (full_write(1, HTTP_200, 9) != 9)
- break;
- rbuf += 8; /* skip "Status: " */
- count = buf_count - 8;
- buf_count = -1; /* buffering off */
- } else if (buf_count >= 4) {
- /* Did CGI add "HTTP"? */
- if (memcmp(rbuf, HTTP_200, 4) != 0) {
- /* there is no "HTTP", do it ourself */
- if (full_write(1, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
- break;
- }
- /* Commented out:
- if (!strstr(rbuf, "ontent-")) {
- full_write(s, "Content-type: text/plain\r\n\r\n", 28);
- }
- * Counter-example of valid CGI without Content-type:
- * echo -en "HTTP/1.0 302 Found\r\n"
- * echo -en "Location: http://www.busybox.net\r\n"
- * echo -en "\r\n"
- */
- count = buf_count;
- buf_count = -1; /* buffering off */
- }
- } else {
- count = safe_read(fromCgi.rd, rbuf, PIPESIZE);
- if (count <= 0)
- break; /* eof (or error) */
- }
- if (full_write(1, rbuf, count) != count)
- break;
- if (DEBUG)
- fprintf(stderr, "cgi read %d bytes: '%.*s'\n", count, count, rbuf);
- } /* if (FD_ISSET(fromCgi.rd)) */
- } /* while (1) */
- log_and_exit();
-}
#endif /* FEATURE_HTTPD_CGI */
/*
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