df1ef312a
Denys Vlasenko
2026-01-28
Subject
httpd: handle bare "Location: URL" redirects from CGIs
Binary
No binary (build failed)
Architecture & Compiler Flags
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 →
networking/httpd.c+29 -14
| @@ -1409,6 +1409,13 @@ static unsigned get_line(void) | |
| } | |
| #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY | |
| + | static void log_cgi_status(const char *pfx, const char *st, unsigned len) |
| + | { |
| + | unsigned char *end = (void*)st; |
| + | while (*end >= ' ' && *end < 0x7f && len > 0) |
| + | end++, len--; |
| + | bb_error_msg("cgi %s:'%.*s'", pfx, (int)((char *)end - st), st); |
| + | } |
| /* gcc 4.2.1 fares better with NOINLINE */ | |
| static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr) NORETURN; | |
| @@ -1416,7 +1423,7 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr) | |
| { | |
| 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 out_cnt; |
| int count; | |
| /* iobuf is used for CGI -> network data, | |
| @@ -1435,8 +1442,15 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr) | |
| G.POST_len -= hdr_cnt; | |
| //bb_error_msg("G.POST_len:%d", G.POST_len); | |
| - | /* NB: breaking out of this loop jumps to log_and_exit() */ |
| + | /* If it's really CGI, we buffer a bit of initial CGI output and handle "Status:" etc */ |
| + | /* If it's proxying, then no buffering/conversion is needed (out_cnt set to -1)*/ |
| + | #if ENABLE_FEATURE_HTTPD_PROXY |
| + | out_cnt = - (fromCgi_rd == toCgi_wr); |
| + | #else |
| out_cnt = 0; | |
| + | #endif |
| + | |
| + | /* NB: breaking out of this loop jumps to log_and_exit() */ |
| pfd[FROM_CGI].fd = fromCgi_rd; | |
| pfd[FROM_CGI].events = POLLIN; | |
| pfd[TO_CGI].fd = toCgi_wr; | |
| @@ -1552,8 +1566,8 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr) | |
| * 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, iobuf + out_cnt, IOBUF_SIZE - 8); |
| - | // "- 8" is important, out_cnt can be up to 7 |
| + | count = safe_read(fromCgi_rd, iobuf + out_cnt, IOBUF_SIZE - 16); |
| + | // "- 16" is important, out_cnt can be up to 9 |
| if (count <= 0) { | |
| /* EOF (or error, and out_cnt=0..7 | |
| * send "HTTP/1.1 200 OK\r\n", then send received 0..7 bytes */ | |
| @@ -1563,9 +1577,8 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr) | |
| } | |
| out_cnt += count; | |
| count = 0; | |
| - | if (out_cnt >= 8) { |
| + | if (out_cnt >= 10) { |
| //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". |
| uint64_t str8 = *(uint64_t*)iobuf; | |
| //bb_error_msg("from cgi:'%.*s'", out_cnt, iobuf); | |
| @@ -1577,18 +1590,20 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr) | |
| memmove(iobuf + 1, iobuf, out_cnt); | |
| out_cnt += 1; | |
| memcpy(iobuf, HTTP_200, 9); | |
| - | if (verbose) { |
| - | char *end = iobuf + 9; |
| - | int cnt = out_cnt - 9; |
| - | while ((unsigned char)*end >= ' ' && (unsigned char)*end < 0x7f && cnt > 0) |
| - | end++, cnt--; |
| - | bb_error_msg("cgi response:'%.*s'", (int)(end - (iobuf + 9)), iobuf + 9); |
| - | } |
| + | if (verbose) |
| + | log_cgi_status("response", iobuf + 9, out_cnt - 9); |
| + | } |
| + | else |
| + | if (str8 == PACK64_LITERAL_STR("Location") && iobuf[8] == ':' && iobuf[9] == ' ') { |
| + | #define HTTP_302 "HTTP/1.1 302 Found\r\n" |
| + | if (full_write(STDOUT_FILENO, HTTP_302, sizeof(HTTP_302)-1) != sizeof(HTTP_302)-1) |
| + | break; |
| + | if (verbose) |
| + | log_cgi_status("redirect", iobuf + 10, out_cnt - 10); |
| } | |
| //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. | |
| else /* Did CGI send "HTTP/1.1"? */ | |
| - | //if (memcmp(iobuf, HTTP_200, 8) != 0) |
| if (str8 != PACK64_LITERAL_STR(HTTP_200)) { | |
| write_HTTP_200_OK: | |
| /* no, send "HTTP/1.1 200 OK\r\n" ourself */ | |