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a5f120b62

Denys Vlasenko
Denys Vlasenko
2026-01-23
SUCCESS Duration: 144s

Subject

httpd: simplify CGI headers handling, check "HTTP/1.1" prefix, not just "HTTP"

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0 
gcc -Wp,-MD,applets/.usage.d -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer      -Iinclude -Iinclude -o applets/usage applets/usage.c

Build Log

(log yok)

Commit Diff GitHub →

include/platform.h +2 -0networking/httpd.c +30 -28
include/platform.h+2 -0
@@ -211,6 +211,7 @@
# define IF_LITTLE_ENDIAN(...)
/* How do bytes a,b,c,d (sequential in memory) look if fetched into uint32_t? */
# define PACK32_BYTES(a,b,c,d) (uint32_t)((d)+((c)<<8)+((b)<<16)+((a)<<24))
+# define PACK64_LITERAL_STR(s) (((uint64_t)PACK32_BYTES((s)[0],(s)[1],(s)[2],(s)[3])<<32) + PACK32_BYTES((s)[4],(s)[5],(s)[6],(s)[7]))
#else
# define SWAP_BE16(x) bswap_16(x)
# define SWAP_BE32(x) bswap_32(x)
@@ -221,6 +222,7 @@
# define IF_BIG_ENDIAN(...)
# define IF_LITTLE_ENDIAN(...) __VA_ARGS__
# define PACK32_BYTES(a,b,c,d) (uint32_t)((a)+((b)<<8)+((c)<<16)+((d)<<24))
+# define PACK64_LITERAL_STR(s) (((uint64_t)PACK32_BYTES((s)[4],(s)[5],(s)[6],(s)[7])<<32) + PACK32_BYTES((s)[0],(s)[1],(s)[2],(s)[3]))
#endif
networking/httpd.c+30 -28
@@ -537,7 +537,7 @@ struct globals {
#if ENABLE_FEATURE_HTTPD_PROXY
Htaccess_Proxy *proxy;
#endif
- char iobuf[IOBUF_SIZE];
+ char iobuf[IOBUF_SIZE] ALIGN8;
};
#define G (*ptr_to_globals)
#define verbose (G.verbose )
@@ -1425,7 +1425,7 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
/*pfd[FROM_CGI].events = POLLIN; - moved out of loop */
/*pfd[FROM_CGI].revents = 0; - not needed */
- /* gcc-4.8.0 still doesnt fill two shorts with one insn :( */
+ /* gcc-4.8.0 still doesn't fill two shorts with one insn :( */
/* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47059 */
/* hopefully one day it will... */
pfd[TO_CGI].events = POLLOUT;
@@ -1507,8 +1507,6 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
if (pfd[FROM_CGI].revents) {
/* There is something to read from CGI */
- char *rbuf = iobuf;
-
/* Still buffering CGI output? */
if (out_cnt >= 0) {
/* HTTP_200[] has single "\r\n" at the end.
@@ -1523,34 +1521,34 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
* 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, IOBUF_SIZE);
+ count = safe_read(fromCgi_rd, iobuf + out_cnt, IOBUF_SIZE);
if (count <= 0) {
- /* eof (or error) and there was no "HTTP" (tiny 0..3 bytes output),
- * send "HTTP/1.1 200 OK\r\n", then send received 0..3 bytes */
+ /* EOF (or error, and out_cnt=0..7
+ * send "HTTP/1.1 200 OK\r\n", then send received 0..7 bytes */
goto write_HTTP_200_OK;
/* we'll read once more later, in "no longer buffering"
* code path, get another EOF there and exit */
}
out_cnt += count;
count = 0;
- /* "Status" header format is: "Status: 302 Redirected\r\n" */
- if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
+ if (out_cnt >= 8) {
//FIXME: "Status: " is not required to be the first header! It can be anywhere!
//FIXME: many servers also check "Location: ". If it exists but "Status: " does _not_, "302 Found" is assumed instead of "200 OK".
- /* send "HTTP/1.1 " */
- if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
- break;
- /* skip "Status: " (including space, sending "HTTP/1.1 NNN" is wrong) */
- rbuf += 8;
- count = out_cnt - 8;
- out_cnt = -1; /* buffering off */
- } else if (out_cnt >= 4) {
-//NB: Apache has no such autodetection. It always adds its own HTTP/ header,
+ /* "Status" header format is: "Status: 302 Redirected\r\n" */
+ //if (memcmp(iobuf, "Status: ", 8) == 0)
+ if (*(uint64_t*)iobuf == PACK64_LITERAL_STR("Status: ")) {
+ /* send "HTTP/1.1 " */
+ if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
+ break;
+ /* skip "Status: " (including space, sending "HTTP/1.1 NNN" is wrong) */
+ out_cnt -= 8;
+ memmove(iobuf, iobuf + 8, out_cnt);
+ }
+//NB: Apache has no such autodetection. It always adds its own HTTP/1.x header,
//unless the CGI name starts with "nph-", in which case it passes its output verbatim to network.
- /* Did CGI add "HTTP"? */
- if (memcmp(rbuf, HTTP_200, 4) != 0) {
+ else if (memcmp(iobuf, HTTP_200, 8) != 0) { /* Did CGI send "HTTP/1.1"? */
write_HTTP_200_OK:
- /* there is no "HTTP", send "HTTP/1.1 200 OK\r\n" ourself */
+ /* no, send "HTTP/1.1 200 OK\r\n" ourself */
if (full_write(STDOUT_FILENO, HTTP_200, sizeof(HTTP_200)-1) != sizeof(HTTP_200)-1)
break;
}
@@ -1562,17 +1560,16 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
*/
count = out_cnt;
out_cnt = -1; /* buffering off */
- /* NB: we mishandle CGI writing "Stat","us..." in two separate writes */
}
} else {
- count = safe_read(fromCgi_rd, rbuf, IOBUF_SIZE);
+ count = safe_read(fromCgi_rd, iobuf, IOBUF_SIZE);
if (count <= 0)
- send_EOF_and_exit(); /* eof (or error) */
+ send_EOF_and_exit(); /* EOF (or error) */
}
-//FIXME: many (most?) servers translate bare "\n" to "\r\n", often only in the headers, not body (the part after empty line)
- if (full_write(STDOUT_FILENO, rbuf, count) != count)
+//FIXME: many (most?) servers translate bare "\n" to "\r\n", only in the headers, not body (the part after empty line)
+ if (full_write(STDOUT_FILENO, iobuf, count) != count)
break;
- dbg("cgi read %d bytes: '%.*s'\n", count, count, rbuf);
+ dbg("cgi read %d bytes: '%.*s'\n", count, count, iobuf);
} /* if (pfd[FROM_CGI].revents) */
} /* while (1) */
log_and_exit();
@@ -2948,7 +2945,12 @@ int httpd_main(int argc UNUSED_PARAM, char **argv)
IF_FEATURE_HTTPD_SETUID(const char *s_ugid = NULL;)
IF_FEATURE_HTTPD_SETUID(struct bb_uidgid_t ugid;)
IF_FEATURE_HTTPD_AUTH_MD5(const char *pass;)
-
+#if 0 // PACK64_LITERAL_STR test
+ char testing[16] = "Status: ";
+ printf("0x%08llx\n", PACK64_LITERAL_STR("Status: "));
+ printf("0x%08llx\n", *(uint64_t*)testing);
+ exit(1);
+#endif
INIT_G();
#if ENABLE_LOCALE_SUPPORT