httpd: pass authorization header to CGI if not Basic
[oweals/busybox.git] / networking / httpd.c
index cfc07075b25d35e0615a55b8f9843f09a4bd1402..0b5d2b481df8f4f47dfc3a3e4437d2f2b2cc4485 100644 (file)
@@ -95,9 +95,7 @@
  * If -c is not set, an attempt will be made to open the default
  * root configuration file.  If -c is set and the file is not found, the
  * server exits with an error.
- *
  */
- /* TODO: use TCP_CORK, parse_config() */
 //config:config HTTPD
 //config:      bool "httpd (32 kb)"
 //config:      default y
 //config:      different user.
 //config:
 //config:config FEATURE_HTTPD_BASIC_AUTH
-//config:      bool "Enable Basic http Authentication"
+//config:      bool "Enable HTTP authentication"
 //config:      default y
 //config:      depends on HTTPD
 //config:      help
 //config:      /adm:toor:PaSsWd
 //config:
 //config:config FEATURE_HTTPD_AUTH_MD5
-//config:      bool "Support MD5 crypted passwords for http Authentication"
+//config:      bool "Support MD5-encrypted passwords in HTTP authentication"
 //config:      default y
 //config:      depends on FEATURE_HTTPD_BASIC_AUTH
 //config:      help
 //usage:     "\n       -e STRING       HTML encode STRING"
 //usage:     "\n       -d STRING       URL decode STRING"
 
+/* TODO: use TCP_CORK, parse_config() */
+
 #include "libbb.h"
 #include "common_bufsiz.h"
 #if ENABLE_PAM
 #define DEBUG 0
 
 #define IOBUF_SIZE 8192
+#define MAX_HTTP_HEADERS_SIZE ((8*1024) - 16)
 #if PIPE_BUF >= IOBUF_SIZE
 # error "PIPE_BUF >= IOBUF_SIZE"
 #endif
@@ -305,6 +306,13 @@ typedef struct Htaccess_Proxy {
        char *url_to;
 } Htaccess_Proxy;
 
+typedef enum CGI_type {
+       CGI_NONE = 0,
+       CGI_NORMAL,
+       CGI_INDEX,
+       CGI_INTERPRETER,
+} CGI_type;
+
 enum {
        HTTP_OK = 200,
        HTTP_PARTIAL_CONTENT = 206,
@@ -316,6 +324,7 @@ enum {
        HTTP_REQUEST_TIMEOUT = 408,
        HTTP_NOT_IMPLEMENTED = 501,   /* used for unrecognized requests */
        HTTP_INTERNAL_SERVER_ERROR = 500,
+       HTTP_ENTITY_TOO_LARGE = 413,
        HTTP_CONTINUE = 100,
 #if 0   /* future use */
        HTTP_SWITCHING_PROTOCOLS = 101,
@@ -347,6 +356,7 @@ static const uint16_t http_response_type[] ALIGN2 = {
        HTTP_BAD_REQUEST,
        HTTP_FORBIDDEN,
        HTTP_INTERNAL_SERVER_ERROR,
+       HTTP_ENTITY_TOO_LARGE,
 #if 0   /* not implemented */
        HTTP_CREATED,
        HTTP_ACCEPTED,
@@ -377,6 +387,7 @@ static const struct {
        { "Bad Request", "Unsupported method" },
        { "Forbidden", ""  },
        { "Internal Server Error", "Internal Server Error" },
+       { "Entity Too Large", "Entity Too Large" },
 #if 0   /* not implemented */
        { "Created" },
        { "Accepted" },
@@ -392,13 +403,15 @@ static const struct {
 struct globals {
        int verbose;            /* must be int (used by getopt32) */
        smallint flg_deny_all;
-
-       unsigned rmt_ip;        /* used for IP-based allow/deny rules */
+#if ENABLE_FEATURE_HTTPD_GZIP
+       /* client can handle gzip / we are going to send gzip */
+       smallint content_gzip;
+#endif
        time_t last_mod;
        char *rmt_ip_str;       /* for $REMOTE_ADDR and $REMOTE_PORT */
        const char *bind_addr_or_port;
 
-       const char *g_query;
+       char *g_query;
        const char *opt_c_configFile;
        const char *home_httpd;
        const char *index_page;
@@ -409,11 +422,6 @@ struct globals {
 
        IF_FEATURE_HTTPD_BASIC_AUTH(const char *g_realm;)
        IF_FEATURE_HTTPD_BASIC_AUTH(char *remoteuser;)
-       IF_FEATURE_HTTPD_CGI(char *referer;)
-       IF_FEATURE_HTTPD_CGI(char *user_agent;)
-       IF_FEATURE_HTTPD_CGI(char *host;)
-       IF_FEATURE_HTTPD_CGI(char *http_accept;)
-       IF_FEATURE_HTTPD_CGI(char *http_accept_language;)
 
        off_t file_size;        /* -1 - unknown */
 #if ENABLE_FEATURE_HTTPD_RANGES
@@ -440,15 +448,15 @@ struct globals {
 #if ENABLE_FEATURE_HTTPD_PROXY
        Htaccess_Proxy *proxy;
 #endif
-#if ENABLE_FEATURE_HTTPD_GZIP
-       /* client can handle gzip / we are going to send gzip */
-       smallint content_gzip;
-#endif
 };
 #define G (*ptr_to_globals)
 #define verbose           (G.verbose          )
 #define flg_deny_all      (G.flg_deny_all     )
-#define rmt_ip            (G.rmt_ip           )
+#if ENABLE_FEATURE_HTTPD_GZIP
+# define content_gzip     (G.content_gzip     )
+#else
+# define content_gzip     0
+#endif
 #define bind_addr_or_port (G.bind_addr_or_port)
 #define g_query           (G.g_query          )
 #define opt_c_configFile  (G.opt_c_configFile )
@@ -481,11 +489,6 @@ enum {
 #define hdr_cnt           (G.hdr_cnt          )
 #define http_error_page   (G.http_error_page  )
 #define proxy             (G.proxy            )
-#if ENABLE_FEATURE_HTTPD_GZIP
-# define content_gzip     (G.content_gzip     )
-#else
-# define content_gzip     0
-#endif
 #define INIT_G() do { \
        setup_common_bufsiz(); \
        SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
@@ -944,7 +947,7 @@ static char *encodeString(const char *string)
                if (isalnum(ch))
                        *p++ = ch;
                else
-                       p += sprintf(p, "&#%d;", (unsigned char) ch);
+                       p += sprintf(p, "&#%u;", (unsigned char) ch);
        }
        *p = '\0';
        return out;
@@ -1040,20 +1043,21 @@ static void log_and_exit(void)
  * second packet is delayed for any reason.
  * responseNum - the result code to send.
  */
-static void send_headers(int responseNum)
+static void send_headers(unsigned responseNum)
 {
        static const char RFC1123FMT[] ALIGN1 = "%a, %d %b %Y %H:%M:%S GMT";
        /* Fixed size 29-byte string. Example: Sun, 06 Nov 1994 08:49:37 GMT */
        char date_str[40]; /* using a bit larger buffer to paranoia reasons */
 
+       struct tm tm;
        const char *responseString = "";
        const char *infoString = NULL;
 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
        const char *error_page = NULL;
 #endif
+       unsigned len;
        unsigned i;
        time_t timer = time(NULL);
-       int len;
 
        for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
                if (http_response_type[i] == responseNum) {
@@ -1074,18 +1078,24 @@ static void send_headers(int responseNum)
         * always fit into those kbytes.
         */
 
-       strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime(&timer));
+       strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime_r(&timer, &tm));
+       /* ^^^ using gmtime_r() instead of gmtime() to not use static data */
        len = sprintf(iobuf,
-                       "HTTP/1.0 %d %s\r\n"
-                       "Content-type: %s\r\n"
+                       "HTTP/1.0 %u %s\r\n"
                        "Date: %s\r\n"
                        "Connection: close\r\n",
                        responseNum, responseString,
-                       /* if it's error message, then it's HTML */
-                       (responseNum == HTTP_OK ? found_mime_type : "text/html"),
                        date_str
        );
 
+       if (responseNum != HTTP_OK || found_mime_type) {
+               len += sprintf(iobuf + len,
+                               "Content-type: %s\r\n",
+                               /* if it's error message, then it's HTML */
+                               (responseNum != HTTP_OK ? "text/html" : found_mime_type)
+               );
+       }
+
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
        if (responseNum == HTTP_UNAUTHORIZED) {
                len += sprintf(iobuf + len,
@@ -1128,7 +1138,7 @@ static void send_headers(int responseNum)
 #endif
 
        if (file_size != -1) {    /* file */
-               strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime(&last_mod));
+               strftime(date_str, sizeof(date_str), RFC1123FMT, gmtime_r(&last_mod, &tm));
 #if ENABLE_FEATURE_HTTPD_RANGES
                if (responseNum == HTTP_PARTIAL_CONTENT) {
                        len += sprintf(iobuf + len,
@@ -1140,18 +1150,61 @@ static void send_headers(int responseNum)
                        file_size = range_end - range_start + 1;
                }
 #endif
+
+//RFC 2616 4.4 Message Length
+// The transfer-length of a message is the length of the message-body as
+// it appears in the message; that is, after any transfer-codings have
+// been applied. When a message-body is included with a message, the
+// transfer-length of that body is determined by one of the following
+// (in order of precedence):
+// 1.Any response message which "MUST NOT" include a message-body (such
+//   as the 1xx, 204, and 304 responses and any response to a HEAD
+//   request) is always terminated by the first empty line after the
+//   header fields, regardless of the entity-header fields present in
+//   the message.
+// 2.If a Transfer-Encoding header field (section 14.41) is present and
+//   has any value other than "identity", then the transfer-length is
+//   defined by use of the "chunked" transfer-coding (section 3.6),
+//   unless the message is terminated by closing the connection.
+// 3.If a Content-Length header field (section 14.13) is present, its
+//   decimal value in OCTETs represents both the entity-length and the
+//   transfer-length. The Content-Length header field MUST NOT be sent
+//   if these two lengths are different (i.e., if a Transfer-Encoding
+//   header field is present). If a message is received with both a
+//   Transfer-Encoding header field and a Content-Length header field,
+//   the latter MUST be ignored.
+// 4.If the message uses the media type "multipart/byteranges" ...
+// 5.By the server closing the connection.
+//
+// (NB: standards do not define "Transfer-Length:" _header_,
+// transfer-length above is just a concept).
+
                len += sprintf(iobuf + len,
 #if ENABLE_FEATURE_HTTPD_RANGES
                        "Accept-Ranges: bytes\r\n"
 #endif
                        "Last-Modified: %s\r\n"
-                       "%s %"OFF_FMT"u\r\n",
+       /* Because of 4.4 (5), we can forgo sending of "Content-Length"
+        * since we close connection afterwards, but it helps clients
+        * to e.g. estimate download times, show progress bars etc.
+        * Theoretically we should not send it if page is compressed,
+        * but de-facto standard is to send it (see comment below).
+        */
+                       "Content-Length: %"OFF_FMT"u\r\n",
                                date_str,
-                               content_gzip ? "Transfer-Length:" : "Content-Length:",
                                file_size
                );
        }
 
+       /* This should be "Transfer-Encoding", not "Content-Encoding":
+        * "data is compressed for transfer", not "data is an archive".
+        * But many clients were not handling "Transfer-Encoding" correctly
+        * (they were not uncompressing gzipped pages, tried to show
+        * raw compressed data), and servers worked around it by using
+        * "Content-Encoding" instead... and this become de-facto standard.
+        * https://bugzilla.mozilla.org/show_bug.cgi?id=68517
+        * https://bugs.chromium.org/p/chromium/issues/detail?id=94730
+        */
        if (content_gzip)
                len += sprintf(iobuf + len, "Content-Encoding: gzip\r\n");
 
@@ -1159,8 +1212,8 @@ static void send_headers(int responseNum)
        iobuf[len++] = '\n';
        if (infoString) {
                len += sprintf(iobuf + len,
-                               "<HTML><HEAD><TITLE>%d %s</TITLE></HEAD>\n"
-                               "<BODY><H1>%d %s</H1>\n"
+                               "<HTML><HEAD><TITLE>%u %s</TITLE></HEAD>\n"
+                               "<BODY><H1>%u %s</H1>\n"
                                "%s\n"
                                "</BODY></HTML>\n",
                                responseNum, responseString,
@@ -1188,37 +1241,39 @@ static void send_headers_and_exit(int responseNum)
 }
 
 /*
- * Read from the socket until '\n' or EOF. '\r' chars are removed.
+ * Read from the socket until '\n' or EOF.
+ * '\r' chars are removed.
  * '\n' is replaced with NUL.
  * Return number of characters read or 0 if nothing is read
  * ('\r' and '\n' are not counted).
  * Data is returned in iobuf.
  */
-static int get_line(void)
+static unsigned get_line(void)
 {
-       int count = 0;
+       unsigned count;
        char c;
 
        alarm(HEADER_READ_TIMEOUT);
+       count = 0;
        while (1) {
                if (hdr_cnt <= 0) {
                        hdr_cnt = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
                        if (hdr_cnt <= 0)
-                               break;
+                               goto ret;
                        hdr_ptr = hdr_buf;
                }
-               iobuf[count] = c = *hdr_ptr++;
                hdr_cnt--;
-
+               c = *hdr_ptr++;
                if (c == '\r')
                        continue;
-               if (c == '\n') {
-                       iobuf[count] = '\0';
+               if (c == '\n')
                        break;
-               }
+               iobuf[count] = c;
                if (count < (IOBUF_SIZE - 1))      /* check overflow */
                        count++;
        }
+ ret:
+       iobuf[count] = '\0';
        return count;
 }
 
@@ -1298,9 +1353,9 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
                                continue;
                        }
                        if (DEBUG && WIFEXITED(status))
-                               bb_error_msg("CGI exited, status=%d", WEXITSTATUS(status));
+                               bb_error_msg("CGI exited, status=%u", WEXITSTATUS(status));
                        if (DEBUG && WIFSIGNALED(status))
-                               bb_error_msg("CGI killed, signal=%d", WTERMSIG(status));
+                               bb_error_msg("CGI killed, signal=%u", WTERMSIG(status));
 #endif
                        break;
                }
@@ -1371,12 +1426,13 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
                                out_cnt += count;
                                count = 0;
                                /* "Status" header format is: "Status: 302 Redirected\r\n" */
-                               if (out_cnt >= 7 && memcmp(rbuf, "Status:", 7) == 0) {
+                               if (out_cnt >= 8 && memcmp(rbuf, "Status: ", 8) == 0) {
                                        /* send "HTTP/1.0 " */
                                        if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
                                                break;
-                                       rbuf += 7; /* skip "Status:" */
-                                       count = out_cnt - 7;
+                                       /* skip "Status: " (including space, sending "HTTP/1.0  NNN" is wrong) */
+                                       rbuf += 8;
+                                       count = out_cnt - 8;
                                        out_cnt = -1; /* buffering off */
                                } else if (out_cnt >= 4) {
                                        /* Did CGI add "HTTP"? */
@@ -1430,23 +1486,17 @@ static void setenv1(const char *name, const char *value)
  * const char *url              The requested URL (with leading /).
  * const char *orig_uri         The original URI before rewriting (if any)
  * 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 *orig_uri,
                const char *request,
-               int post_len,
-               const char *cookie,
-               const char *content_type) NORETURN;
+               int post_len) NORETURN;
 static void send_cgi_and_exit(
                const char *url,
                const char *orig_uri,
                const char *request,
-               int post_len,
-               const char *cookie,
-               const char *content_type)
+               int post_len)
 {
        struct fd_pair fromCgi;  /* CGI -> httpd pipe */
        struct fd_pair toCgi;    /* httpd -> CGI pipe */
@@ -1524,26 +1574,14 @@ static void send_cgi_and_exit(
 #endif
                }
        }
-       setenv1("HTTP_USER_AGENT", G.user_agent);
-       if (G.http_accept)
-               setenv1("HTTP_ACCEPT", G.http_accept);
-       if (G.http_accept_language)
-               setenv1("HTTP_ACCEPT_LANGUAGE", G.http_accept_language);
        if (post_len)
-               putenv(xasprintf("CONTENT_LENGTH=%d", post_len));
-       if (cookie)
-               setenv1("HTTP_COOKIE", cookie);
-       if (content_type)
-               setenv1("CONTENT_TYPE", content_type);
+               putenv(xasprintf("CONTENT_LENGTH=%u", post_len));
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
        if (remoteuser) {
                setenv1("REMOTE_USER", remoteuser);
                putenv((char*)"AUTH_TYPE=Basic");
        }
 #endif
-       if (G.referer)
-               setenv1("HTTP_REFERER", G.referer);
-       setenv1("HTTP_HOST", G.host); /* set to "" if NULL */
        /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
         * just run "env SERVER_NAME=xyz httpd ..." instead */
 
@@ -1681,8 +1719,8 @@ static NOINLINE void send_file_and_exit(const char *url, int what)
         * (happens if you abort downloads from local httpd): */
        signal(SIGPIPE, SIG_IGN);
 
-       /* If not found, default is "application/octet-stream" */
-       found_mime_type = "application/octet-stream";
+       /* If not found, default is to not send "Content-type:" */
+       /*found_mime_type = NULL; - already is */
        suffix = strrchr(url, '.');
        if (suffix) {
                static const char suffixTable[] ALIGN1 =
@@ -1810,7 +1848,7 @@ static NOINLINE void send_file_and_exit(const char *url, int what)
        log_and_exit();
 }
 
-static int checkPermIP(void)
+static void if_ip_denied_send_HTTP_FORBIDDEN_and_exit(unsigned remote_ip)
 {
        Htaccess_IP *cur;
 
@@ -1829,11 +1867,15 @@ static int checkPermIP(void)
                        (unsigned char)(cur->mask)
                );
 #endif
-               if ((rmt_ip & cur->mask) == cur->ip)
-                       return (cur->allow_deny == 'A'); /* A -> 1 */
+               if ((remote_ip & cur->mask) == cur->ip) {
+                       if (cur->allow_deny == 'A')
+                               return;
+                       send_headers_and_exit(HTTP_FORBIDDEN);
+               }
        }
 
-       return !flg_deny_all; /* depends on whether we saw "D:*" */
+       if (flg_deny_all) /* depends on whether we saw "D:*" */
+               send_headers_and_exit(HTTP_FORBIDDEN);
 }
 
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
@@ -2070,12 +2112,15 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
        char *urlcopy;
        char *urlp;
        char *tptr;
+       unsigned remote_ip;
+#if ENABLE_FEATURE_HTTPD_CGI
+       unsigned total_headers_len;
+#endif
 #if ENABLE_FEATURE_HTTPD_CGI
        static const char request_HEAD[] ALIGN1 = "HEAD";
        const char *prequest;
-       char *cookie = NULL;
-       char *content_type = NULL;
        unsigned long length = 0;
+       enum CGI_type cgi_type = CGI_NONE;
 #elif ENABLE_FEATURE_HTTPD_PROXY
 #define prequest request_GET
        unsigned long length = 0;
@@ -2083,29 +2128,23 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
        smallint authorized = -1;
 #endif
-       smallint ip_allowed;
        char http_major_version;
-#if ENABLE_FEATURE_HTTPD_PROXY
-       char http_minor_version;
-       char *header_buf = header_buf; /* for gcc */
-       char *header_ptr = header_ptr;
-       Htaccess_Proxy *proxy_entry;
-#endif
+       char *HTTP_slash;
 
        /* Allocation of iobuf is postponed until now
         * (IOW, server process doesn't need to waste 8k) */
        iobuf = xmalloc(IOBUF_SIZE);
 
-       rmt_ip = 0;
+       remote_ip = 0;
        if (fromAddr->u.sa.sa_family == AF_INET) {
-               rmt_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
+               remote_ip = ntohl(fromAddr->u.sin.sin_addr.s_addr);
        }
 #if ENABLE_FEATURE_IPV6
        if (fromAddr->u.sa.sa_family == AF_INET6
         && fromAddr->u.sin6.sin6_addr.s6_addr32[0] == 0
         && fromAddr->u.sin6.sin6_addr.s6_addr32[1] == 0
         && ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[2]) == 0xffff)
-               rmt_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
+               remote_ip = ntohl(fromAddr->u.sin6.sin6_addr.s6_addr32[3]);
 #endif
        if (ENABLE_FEATURE_HTTPD_CGI || DEBUG || verbose) {
                /* NB: can be NULL (user runs httpd -i by hand?) */
@@ -2118,6 +2157,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                if (verbose > 2)
                        bb_error_msg("connected");
        }
+       if_ip_denied_send_HTTP_FORBIDDEN_and_exit(remote_ip);
 
        /* Install timeout handler. get_line() needs it. */
        signal(SIGALRM, send_REQUEST_TIMEOUT_and_exit);
@@ -2152,30 +2192,58 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                send_headers_and_exit(HTTP_BAD_REQUEST);
 
        /* Find end of URL and parse HTTP version, if any */
-       http_major_version = '0';
-       IF_FEATURE_HTTPD_PROXY(http_minor_version = '0';)
-       tptr = strchrnul(urlp, ' ');
+//TODO: maybe just reject all queries which have no " HTTP/xyz" suffix?
+//Then 'http_major_version' can be deleted
+       http_major_version = ('0' - 1); /* "less than 0th" version */
+       HTTP_slash = strchrnul(urlp, ' ');
        /* Is it " HTTP/"? */
-       if (tptr[0] && strncmp(tptr + 1, HTTP_200, 5) == 0) {
-               http_major_version = tptr[6];
-               IF_FEATURE_HTTPD_PROXY(http_minor_version = tptr[8];)
+       if (HTTP_slash[0] && strncmp(HTTP_slash + 1, HTTP_200, 5) == 0) {
+               http_major_version = HTTP_slash[6];
+               *HTTP_slash++ = '\0';
        }
-       *tptr = '\0';
 
        /* Copy URL from after "GET "/"POST " to stack-allocated char[] */
-       urlcopy = alloca((tptr - urlp) + 2 + strlen(index_page));
+       urlcopy = alloca((HTTP_slash - urlp) + 2 + strlen(index_page));
        /*if (urlcopy == NULL)
         *      send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);*/
        strcpy(urlcopy, urlp);
        /* NB: urlcopy ptr is never changed after this */
 
-       /* Extract url args if present */
-       /* g_query = NULL; - already is */
-       tptr = strchr(urlcopy, '?');
-       if (tptr) {
-               *tptr++ = '\0';
-               g_query = tptr;
+#if ENABLE_FEATURE_HTTPD_PROXY
+       {
+               int proxy_fd;
+               len_and_sockaddr *lsa;
+               Htaccess_Proxy *proxy_entry = find_proxy_entry(urlcopy);
+
+               if (proxy_entry) {
+                       lsa = host2sockaddr(proxy_entry->host_port, 80);
+                       if (!lsa)
+                               send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
+                       proxy_fd = socket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
+                       if (proxy_fd < 0)
+                               send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
+                       if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
+                               send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
+                       /* Config directive was of the form:
+                        *   P:/url:[http://]hostname[:port]/new/path
+                        * When /urlSFX is requested, reverse proxy it
+                        * to http://hostname[:port]/new/pathSFX
+                        */
+                       fdprintf(proxy_fd, "%s %s%s %s\r\n",
+                                       prequest, /* "GET" or "POST" */
+                                       proxy_entry->url_to, /* "/new/path" */
+                                       urlcopy + strlen(proxy_entry->url_from), /* "SFX" */
+                                       HTTP_slash /* HTTP/xyz" or "" */
+                       );
+                       cgi_io_loop_and_exit(proxy_fd, proxy_fd, /*max POST length:*/ INT_MAX);
+               }
        }
+#endif
+
+       /* Extract url args if present */
+       g_query = strchr(urlcopy, '?');
+       if (g_query)
+               *g_query++ = '\0';
 
        /* Decode URL escape sequences */
        tptr = percent_decode_in_place(urlcopy, /*strict:*/ 1);
@@ -2215,7 +2283,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                        }
                }
                *++urlp = *tptr;
-               if (*urlp == '\0')
+               if (*tptr == '\0')
                        break;
  next_char:
                tptr++;
@@ -2233,50 +2301,90 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                bb_error_msg("url:%s", urlcopy);
 
        tptr = urlcopy;
-       ip_allowed = checkPermIP();
-       while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
+       while ((tptr = strchr(tptr + 1, '/')) != NULL) {
                /* have path1/path2 */
                *tptr = '\0';
                if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
                        /* may have subdir config */
                        parse_conf(urlcopy + 1, SUBDIR_PARSE);
-                       ip_allowed = checkPermIP();
+                       if_ip_denied_send_HTTP_FORBIDDEN_and_exit(remote_ip);
                }
                *tptr = '/';
        }
 
-#if ENABLE_FEATURE_HTTPD_PROXY
-       proxy_entry = find_proxy_entry(urlcopy);
-       if (proxy_entry)
-               header_buf = header_ptr = xmalloc(IOBUF_SIZE);
+       tptr = urlcopy + 1;      /* skip first '/' */
+
+#if ENABLE_FEATURE_HTTPD_CGI
+       if (is_prefixed_with(tptr, "cgi-bin/")) {
+               if (tptr[8] == '\0') {
+                       /* protect listing "cgi-bin/" */
+                       send_headers_and_exit(HTTP_FORBIDDEN);
+               }
+               cgi_type = CGI_NORMAL;
+       }
+#endif
+
+       if (urlp[-1] == '/') {
+               /* When index_page string is appended to <dir>/ URL, it overwrites
+                * the query string. If we fall back to call /cgi-bin/index.cgi,
+                * query string would be lost and not available to the CGI.
+                * Work around it by making a deep copy.
+                */
+               if (ENABLE_FEATURE_HTTPD_CGI)
+                       g_query = xstrdup(g_query); /* ok for NULL too */
+               strcpy(urlp, index_page);
+       }
+       if (stat(tptr, &sb) == 0) {
+#if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
+               char *suffix = strrchr(tptr, '.');
+               if (suffix) {
+                       Htaccess *cur;
+                       for (cur = script_i; cur; cur = cur->next) {
+                               if (strcmp(cur->before_colon + 1, suffix) == 0) {
+                                       cgi_type = CGI_INTERPRETER;
+                                       break;
+                               }
+                       }
+               }
 #endif
+               if (!found_moved_temporarily) {
+                       file_size = sb.st_size;
+                       last_mod = sb.st_mtime;
+               }
+       }
+#if ENABLE_FEATURE_HTTPD_CGI
+       else if (urlp[-1] == '/') {
+               /* It's a dir URL and there is no index.html
+                * Try cgi-bin/index.cgi */
+               if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
+                       cgi_type = CGI_INDEX;
+               }
+       }
+#endif
+       urlp[0] = '\0';
 
+#if ENABLE_FEATURE_HTTPD_CGI
+       total_headers_len = 0;
+#endif
        if (http_major_version >= '0') {
                /* Request was with "... HTTP/nXXX", and n >= 0 */
 
                /* Read until blank line */
                while (1) {
-                       if (!get_line())
+                       unsigned iobuf_len = get_line();
+                       if (!iobuf_len)
                                break; /* EOF or error or empty line */
+#if ENABLE_FEATURE_HTTPD_CGI
+                       /* Prevent unlimited growth of HTTP_xyz envvars */
+                       total_headers_len += iobuf_len;
+                       if (total_headers_len >= MAX_HTTP_HEADERS_SIZE)
+                               send_headers_and_exit(HTTP_ENTITY_TOO_LARGE);
+#endif
                        if (DEBUG)
                                bb_error_msg("header: '%s'", iobuf);
-
-#if ENABLE_FEATURE_HTTPD_PROXY
-                       /* We need 2 more bytes for yet another "\r\n" -
-                        * see near fdprintf(proxy_fd...) further below */
-                       if (proxy_entry && (header_ptr - header_buf) < IOBUF_SIZE - 4) {
-                               int len = strnlen(iobuf, IOBUF_SIZE - (header_ptr - header_buf) - 4);
-                               memcpy(header_ptr, iobuf, len);
-                               header_ptr += len;
-                               header_ptr[0] = '\r';
-                               header_ptr[1] = '\n';
-                               header_ptr += 2;
-                       }
-#endif
-
 #if ENABLE_FEATURE_HTTPD_CGI || ENABLE_FEATURE_HTTPD_PROXY
                        /* Try and do our best to parse more lines */
-                       if ((STRNCASECMP(iobuf, "Content-Length:") == 0)) {
+                       if (STRNCASECMP(iobuf, "Content-Length:") == 0) {
                                /* extra read only for POST */
                                if (prequest != request_GET
 # if ENABLE_FEATURE_HTTPD_CGI
@@ -2292,30 +2400,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                                        if (errno || length > INT_MAX)
                                                send_headers_and_exit(HTTP_BAD_REQUEST);
                                }
-                       }
-#endif
-#if ENABLE_FEATURE_HTTPD_CGI
-                       else if (STRNCASECMP(iobuf, "Cookie:") == 0) {
-                               if (!cookie) /* in case they send millions of these, do not OOM */
-                                       cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
-                       } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
-                               if (!content_type)
-                                       content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
-                       } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
-                               if (!G.referer)
-                                       G.referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
-                       } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
-                               if (!G.user_agent)
-                                       G.user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
-                       } else if (STRNCASECMP(iobuf, "Host:") == 0) {
-                               if (!G.host)
-                                       G.host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
-                       } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
-                               if (!G.http_accept)
-                                       G.http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
-                       } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
-                               if (!G.http_accept_language)
-                                       G.http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
+                               continue;
                        }
 #endif
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
@@ -2325,19 +2410,20 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                                 * "<user>:<passwd>" is base64 encoded.
                                 */
                                tptr = skip_whitespace(iobuf + sizeof("Authorization:")-1);
-                               if (STRNCASECMP(tptr, "Basic") != 0)
+                               if (STRNCASECMP(tptr, "Basic") == 0) {
+                                       tptr += sizeof("Basic")-1;
+                                       /* decodeBase64() skips whitespace itself */
+                                       decodeBase64(tptr);
+                                       authorized = check_user_passwd(urlcopy, tptr);
                                        continue;
-                               tptr += sizeof("Basic")-1;
-                               /* decodeBase64() skips whitespace itself */
-                               decodeBase64(tptr);
-                               authorized = check_user_passwd(urlcopy, tptr);
+                               }
                        }
 #endif
 #if ENABLE_FEATURE_HTTPD_RANGES
                        if (STRNCASECMP(iobuf, "Range:") == 0) {
                                /* We know only bytes=NNN-[MMM] */
                                char *s = skip_whitespace(iobuf + sizeof("Range:")-1);
-                               if (is_prefixed_with(s, "bytes=") == 0) {
+                               if (is_prefixed_with(s, "bytes=")) {
                                        s += sizeof("bytes=")-1;
                                        range_start = BB_STRTOOFF(s, &s, 10);
                                        if (s[0] != '-' || range_start < 0) {
@@ -2348,6 +2434,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                                                        range_start = -1;
                                        }
                                }
+                               continue;
                        }
 #endif
 #if ENABLE_FEATURE_HTTPD_GZIP
@@ -2365,6 +2452,35 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                                                content_gzip = 1;
                                        //}
                                }
+                               continue;
+                       }
+#endif
+#if ENABLE_FEATURE_HTTPD_CGI
+                       if (cgi_type != CGI_NONE) {
+                               bool ct = (STRNCASECMP(iobuf, "Content-Type:") == 0);
+                               char *cp;
+                               char *colon = strchr(iobuf, ':');
+
+                               if (!colon)
+                                       continue;
+                               cp = iobuf;
+                               while (cp < colon) {
+                                       /* a-z => A-Z, not-alnum => _ */
+                                       char c = (*cp & ~0x20); /* toupper for A-Za-z, undef for others */
+                                       if ((unsigned)(c - 'A') <= ('Z' - 'A')) {
+                                               *cp++ = c;
+                                               continue;
+                                       }
+                                       if (!isdigit(*cp))
+                                               *cp = '_';
+                                       cp++;
+                               }
+                               /* "Content-Type:" gets no HTTP_ prefix, all others do */
+                               cp = xasprintf(ct ? "HTTP_%.*s=%s" + 5 : "HTTP_%.*s=%s",
+                                       (int)(colon - iobuf), iobuf,
+                                       skip_whitespace(colon + 1)
+                               );
+                               putenv(cp);
                        }
 #endif
                } /* while extra header reading */
@@ -2373,7 +2489,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
        /* We are done reading headers, disable peer timeout */
        alarm(0);
 
-       if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0 || !ip_allowed) {
+       if (strcmp(bb_basename(urlcopy), HTTPD_CONF) == 0) {
                /* protect listing [/path]/httpd.conf or IP deny */
                send_headers_and_exit(HTTP_FORBIDDEN);
        }
@@ -2391,83 +2507,23 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                send_headers_and_exit(HTTP_MOVED_TEMPORARILY);
        }
 
-#if ENABLE_FEATURE_HTTPD_PROXY
-       if (proxy_entry != NULL) {
-               int proxy_fd;
-               len_and_sockaddr *lsa;
-
-               lsa = host2sockaddr(proxy_entry->host_port, 80);
-               if (lsa == NULL)
-                       send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
-               proxy_fd = socket(lsa->u.sa.sa_family, SOCK_STREAM, 0);
-               if (proxy_fd < 0)
-                       send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
-               if (connect(proxy_fd, &lsa->u.sa, lsa->len) < 0)
-                       send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
-               fdprintf(proxy_fd, "%s %s%s%s%s HTTP/%c.%c\r\n",
-                               prequest, /* GET or POST */
-                               proxy_entry->url_to, /* url part 1 */
-                               urlcopy + strlen(proxy_entry->url_from), /* url part 2 */
-                               (g_query ? "?" : ""), /* "?" (maybe) */
-                               (g_query ? g_query : ""), /* query string (maybe) */
-                               http_major_version, http_minor_version);
-               header_ptr[0] = '\r';
-               header_ptr[1] = '\n';
-               header_ptr += 2;
-               write(proxy_fd, header_buf, header_ptr - header_buf);
-               free(header_buf); /* on the order of 8k, free it */
-               cgi_io_loop_and_exit(proxy_fd, proxy_fd, length);
-       }
-#endif
-
        tptr = urlcopy + 1;      /* skip first '/' */
 
 #if ENABLE_FEATURE_HTTPD_CGI
-       if (is_prefixed_with(tptr, "cgi-bin/")) {
-               if (tptr[8] == '\0') {
-                       /* protect listing "cgi-bin/" */
-                       send_headers_and_exit(HTTP_FORBIDDEN);
-               }
-               send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
+       if (cgi_type != CGI_NONE) {
+               send_cgi_and_exit(
+                       (cgi_type == CGI_INDEX) ? "/cgi-bin/index.cgi"
+                       /*CGI_NORMAL or CGI_INTERPRETER*/ : urlcopy,
+                       urlcopy, prequest, length
+               );
        }
 #endif
 
        if (urlp[-1] == '/') {
-               /* When index_page string is appended to <dir>/ URL, it overwrites
-                * the query string. If we fall back to call /cgi-bin/index.cgi,
-                * query string would be lost and not available to the CGI.
-                * Work around it by making a deep copy.
-                */
-               if (ENABLE_FEATURE_HTTPD_CGI)
-                       g_query = xstrdup(g_query); /* ok for NULL too */
                strcpy(urlp, index_page);
        }
-       if (stat(tptr, &sb) == 0) {
-#if ENABLE_FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
-               char *suffix = strrchr(tptr, '.');
-               if (suffix) {
-                       Htaccess *cur;
-                       for (cur = script_i; cur; cur = cur->next) {
-                               if (strcmp(cur->before_colon + 1, suffix) == 0) {
-                                       send_cgi_and_exit(urlcopy, urlcopy, prequest, length, cookie, content_type);
-                               }
-                       }
-               }
-#endif
-               file_size = sb.st_size;
-               last_mod = sb.st_mtime;
-       }
-#if ENABLE_FEATURE_HTTPD_CGI
-       else if (urlp[-1] == '/') {
-               /* It's a dir URL and there is no index.html
-                * Try cgi-bin/index.cgi */
-               if (access("/cgi-bin/index.cgi"+1, X_OK) == 0) {
-                       urlp[0] = '\0'; /* remove index_page */
-                       send_cgi_and_exit("/cgi-bin/index.cgi", urlcopy, prequest, length, cookie, content_type);
-               }
-       }
-       /* else fall through to send_file, it errors out if open fails: */
 
+#if ENABLE_FEATURE_HTTPD_CGI
        if (prequest != request_GET && prequest != request_HEAD) {
                /* POST for files does not make sense */
                send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
@@ -2540,11 +2596,9 @@ static void mini_httpd_nommu(int server_socket, int argc, char **argv)
         */
        while (1) {
                int n;
-               len_and_sockaddr fromAddr;
 
                /* Wait for connections... */
-               fromAddr.len = LSA_SIZEOF_SA;
-               n = accept(server_socket, &fromAddr.u.sa, &fromAddr.len);
+               n = accept(server_socket, NULL, NULL);
                if (n < 0)
                        continue;
 
@@ -2588,7 +2642,9 @@ static void mini_httpd_inetd(void)
 
 static void sighup_handler(int sig UNUSED_PARAM)
 {
+       int sv = errno;
        parse_conf(DEFAULT_PATH_HTTPD_CONF, SIGNALED_PARSE);
+       errno = sv;
 }
 
 enum {
@@ -2636,17 +2692,19 @@ int httpd_main(int argc UNUSED_PARAM, char **argv)
 #endif
 
        home_httpd = xrealloc_getcwd_or_warn(NULL);
-       /* -v counts, -i implies -f */
-       opt_complementary = "vv:if";
        /* We do not "absolutize" path given by -h (home) opt.
         * If user gives relative path in -h,
         * $SCRIPT_FILENAME will not be set. */
-       opt = getopt32(argv, "c:d:h:"
+       opt = getopt32(argv, "^"
+                       "c:d:h:"
                        IF_FEATURE_HTTPD_ENCODE_URL_STR("e:")
                        IF_FEATURE_HTTPD_BASIC_AUTH("r:")
                        IF_FEATURE_HTTPD_AUTH_MD5("m:")
                        IF_FEATURE_HTTPD_SETUID("u:")
-                       "p:ifv",
+                       "p:ifv"
+                       "\0"
+                       /* -v counts, -i implies -f */
+                       "vv:if",
                        &opt_c_configFile, &url_for_decode, &home_httpd
                        IF_FEATURE_HTTPD_ENCODE_URL_STR(, &url_for_encode)
                        IF_FEATURE_HTTPD_BASIC_AUTH(, &g_realm)
@@ -2729,7 +2787,7 @@ int httpd_main(int argc UNUSED_PARAM, char **argv)
 
        xfunc_error_retval = 0;
        if (opt & OPT_INETD)
-               mini_httpd_inetd();
+               mini_httpd_inetd(); /* never returns */
 #if BB_MMU
        if (!(opt & OPT_FOREGROUND))
                bb_daemonize(0); /* don't change current directory */