httpd: pass authorization header to CGI if not Basic
[oweals/busybox.git] / networking / httpd.c
index cda7cc7af528e3ea5000d625f3c5e38065e4e0b4..0b5d2b481df8f4f47dfc3a3e4437d2f2b2cc4485 100644 (file)
  * 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:      help
+//config:      HTTP server.
+//config:
+//config:config FEATURE_HTTPD_RANGES
+//config:      bool "Support 'Ranges:' header"
+//config:      default y
+//config:      depends on HTTPD
+//config:      help
+//config:      Makes httpd emit "Accept-Ranges: bytes" header and understand
+//config:      "Range: bytes=NNN-[MMM]" header. Allows for resuming interrupted
+//config:      downloads, seeking in multimedia players etc.
+//config:
+//config:config FEATURE_HTTPD_SETUID
+//config:      bool "Enable -u <user> option"
+//config:      default y
+//config:      depends on HTTPD
+//config:      help
+//config:      This option allows the server to run as a specific user
+//config:      rather than defaulting to the user that starts the server.
+//config:      Use of this option requires special privileges to change to a
+//config:      different user.
+//config:
+//config:config FEATURE_HTTPD_BASIC_AUTH
+//config:      bool "Enable HTTP authentication"
+//config:      default y
+//config:      depends on HTTPD
+//config:      help
+//config:      Utilizes password settings from /etc/httpd.conf for basic
+//config:      authentication on a per url basis.
+//config:      Example for httpd.conf file:
+//config:      /adm:toor:PaSsWd
+//config:
+//config:config FEATURE_HTTPD_AUTH_MD5
+//config:      bool "Support MD5-encrypted passwords in HTTP authentication"
+//config:      default y
+//config:      depends on FEATURE_HTTPD_BASIC_AUTH
+//config:      help
+//config:      Enables encrypted passwords, and wildcard user/passwords
+//config:      in httpd.conf file.
+//config:      User '*' means 'any system user name is ok',
+//config:      password of '*' means 'use system password for this user'
+//config:      Examples:
+//config:      /adm:toor:$1$P/eKnWXS$aI1aPGxT.dJD5SzqAKWrF0
+//config:      /adm:root:*
+//config:      /wiki:*:*
+//config:
+//config:config FEATURE_HTTPD_CGI
+//config:      bool "Support Common Gateway Interface (CGI)"
+//config:      default y
+//config:      depends on HTTPD
+//config:      help
+//config:      This option allows scripts and executables to be invoked
+//config:      when specific URLs are requested.
+//config:
+//config:config FEATURE_HTTPD_CONFIG_WITH_SCRIPT_INTERPR
+//config:      bool "Support running scripts through an interpreter"
+//config:      default y
+//config:      depends on FEATURE_HTTPD_CGI
+//config:      help
+//config:      This option enables support for running scripts through an
+//config:      interpreter. Turn this on if you want PHP scripts to work
+//config:      properly. You need to supply an additional line in your
+//config:      httpd.conf file:
+//config:      *.php:/path/to/your/php
+//config:
+//config:config FEATURE_HTTPD_SET_REMOTE_PORT_TO_ENV
+//config:      bool "Set REMOTE_PORT environment variable for CGI"
+//config:      default y
+//config:      depends on FEATURE_HTTPD_CGI
+//config:      help
+//config:      Use of this option can assist scripts in generating
+//config:      references that contain a unique port number.
+//config:
+//config:config FEATURE_HTTPD_ENCODE_URL_STR
+//config:      bool "Enable -e option (useful for CGIs written as shell scripts)"
+//config:      default y
+//config:      depends on HTTPD
+//config:      help
+//config:      This option allows html encoding of arbitrary strings for display
+//config:      by the browser. Output goes to stdout.
+//config:      For example, httpd -e "<Hello World>" produces
+//config:      "&#60Hello&#32World&#62".
+//config:
+//config:config FEATURE_HTTPD_ERROR_PAGES
+//config:      bool "Support custom error pages"
+//config:      default y
+//config:      depends on HTTPD
+//config:      help
+//config:      This option allows you to define custom error pages in
+//config:      the configuration file instead of the default HTTP status
+//config:      error pages. For instance, if you add the line:
+//config:              E404:/path/e404.html
+//config:      in the config file, the server will respond the specified
+//config:      '/path/e404.html' file instead of the terse '404 NOT FOUND'
+//config:      message.
+//config:
+//config:config FEATURE_HTTPD_PROXY
+//config:      bool "Support reverse proxy"
+//config:      default y
+//config:      depends on HTTPD
+//config:      help
+//config:      This option allows you to define URLs that will be forwarded
+//config:      to another HTTP server. To setup add the following line to the
+//config:      configuration file
+//config:              P:/url/:http://hostname[:port]/new/path/
+//config:      Then a request to /url/myfile will be forwarded to
+//config:      http://hostname[:port]/new/path/myfile.
+//config:
+//config:config FEATURE_HTTPD_GZIP
+//config:      bool "Support GZIP content encoding"
+//config:      default y
+//config:      depends on HTTPD
+//config:      help
+//config:      Makes httpd send files using GZIP content encoding if the
+//config:      client supports it and a pre-compressed <file>.gz exists.
+
+//applet:IF_HTTPD(APPLET(httpd, BB_DIR_USR_SBIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_HTTPD) += httpd.o
 
 //usage:#define httpd_trivial_usage
 //usage:       "[-ifv[v]]"
 //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
 /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
 # undef setlocale
 # include <security/pam_appl.h>
 # include <security/pam_misc.h>
 #endif
-#if ENABLE_FEATURE_HTTPD_USE_SENDFILE
+#if ENABLE_FEATURE_USE_SENDFILE
 # include <sys/sendfile.h>
 #endif
 /* amount of buffering in a pipe */
 #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
@@ -182,6 +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,
@@ -193,6 +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,
@@ -224,6 +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,
@@ -254,6 +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" },
@@ -269,13 +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;
@@ -286,11 +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
@@ -307,7 +438,8 @@ struct globals {
        Htaccess *script_i;     /* config script interpreters */
 #endif
        char *iobuf;            /* [IOBUF_SIZE] */
-#define hdr_buf bb_common_bufsiz1
+#define        hdr_buf bb_common_bufsiz1
+#define sizeof_hdr_buf COMMON_BUFSIZE
        char *hdr_ptr;
        int hdr_cnt;
 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
@@ -316,15 +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 )
@@ -336,11 +468,6 @@ struct globals {
 #define ip_a_d            (G.ip_a_d           )
 #define g_realm           (G.g_realm          )
 #define remoteuser        (G.remoteuser       )
-#define referer           (G.referer          )
-#define user_agent        (G.user_agent       )
-#define host              (G.host             )
-#define http_accept       (G.http_accept      )
-#define http_accept_language (G.http_accept_language)
 #define file_size         (G.file_size        )
 #if ENABLE_FEATURE_HTTPD_RANGES
 #define range_start       (G.range_start      )
@@ -348,7 +475,7 @@ struct globals {
 #define range_len         (G.range_len        )
 #else
 enum {
-       range_start = 0,
+       range_start = -1,
        range_end = MAXINT(off_t) - 1,
        range_len = MAXINT(off_t),
 };
@@ -362,14 +489,11 @@ 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))); \
        IF_FEATURE_HTTPD_BASIC_AUTH(g_realm = "Web Server Authentication";) \
+       IF_FEATURE_HTTPD_RANGES(range_start = -1;) \
        bind_addr_or_port = "80"; \
        index_page = index_html; \
        file_size = -1; \
@@ -696,7 +820,7 @@ static void parse_conf(const char *path, int flag)
                                goto config_error;
                        }
                        *host_port++ = '\0';
-                       if (strncmp(host_port, "http://", 7) == 0)
+                       if (is_prefixed_with(host_port, "http://"))
                                host_port += 7;
                        if (*host_port == '\0') {
                                goto config_error;
@@ -795,9 +919,9 @@ static void parse_conf(const char *path, int flag)
                /* the line is not recognized */
  config_error:
                bb_error_msg("config error '%s' in '%s'", buf, filename);
-        } /* while (fgets) */
+       } /* while (fgets) */
 
-        fclose(f);
+       fclose(f);
 }
 
 #if ENABLE_FEATURE_HTTPD_ENCODE_URL_STR
@@ -823,7 +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;
@@ -919,20 +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;
-       const char *mime_type;
 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
        const char *error_page = NULL;
 #endif
+       unsigned len;
        unsigned i;
        time_t timer = time(NULL);
-       char tmp_str[80];
-       int len;
 
        for (i = 0; i < ARRAY_SIZE(http_response_type); i++) {
                if (http_response_type[i] == responseNum) {
@@ -944,41 +1069,67 @@ static void send_headers(int responseNum)
                        break;
                }
        }
-       /* error message is HTML */
-       mime_type = responseNum == HTTP_OK ?
-                               found_mime_type : "text/html";
 
        if (verbose)
                bb_error_msg("response:%u", responseNum);
 
-       /* emit the current date */
-       strftime(tmp_str, sizeof(tmp_str), RFC1123FMT, gmtime(&timer));
+       /* We use sprintf, not snprintf (it's less code).
+        * iobuf[] is several kbytes long and all headers we generate
+        * always fit into those kbytes.
+        */
+
+       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\nContent-type: %s\r\n"
-                       "Date: %s\r\nConnection: close\r\n",
-                       responseNum, responseString, mime_type, tmp_str);
+                       "HTTP/1.0 %u %s\r\n"
+                       "Date: %s\r\n"
+                       "Connection: close\r\n",
+                       responseNum, responseString,
+                       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,
-                               "WWW-Authenticate: Basic realm=\"%s\"\r\n",
-                               g_realm);
+                               "WWW-Authenticate: Basic realm=\"%.999s\"\r\n",
+                               g_realm /* %.999s protects from overflowing iobuf[] */
+               );
        }
 #endif
        if (responseNum == HTTP_MOVED_TEMPORARILY) {
-               len += sprintf(iobuf + len, "Location: %s/%s%s\r\n",
+               /* Responding to "GET /dir" with
+                * "HTTP/1.0 302 Found" "Location: /dir/"
+                * - IOW, asking them to repeat with a slash.
+                * Here, overflow IS possible, can't use sprintf:
+                * mkdir test
+                * python -c 'print("get /test?" + ("x" * 8192))' | busybox httpd -i -h .
+                */
+               len += snprintf(iobuf + len, IOBUF_SIZE-3 - len,
+                               "Location: %s/%s%s\r\n",
                                found_moved_temporarily,
                                (g_query ? "?" : ""),
-                               (g_query ? g_query : ""));
+                               (g_query ? g_query : "")
+               );
+               if (len > IOBUF_SIZE-3)
+                       len = IOBUF_SIZE-3;
        }
 
 #if ENABLE_FEATURE_HTTPD_ERROR_PAGES
        if (error_page && access(error_page, R_OK) == 0) {
-               strcat(iobuf, "\r\n");
-               len += 2;
-
-               if (DEBUG)
+               iobuf[len++] = '\r';
+               iobuf[len++] = '\n';
+               if (DEBUG) {
+                       iobuf[len] = '\0';
                        fprintf(stderr, "headers: '%s'\n", iobuf);
+               }
                full_write(STDOUT_FILENO, iobuf, len);
                if (DEBUG)
                        fprintf(stderr, "writing error page: '%s'\n", error_page);
@@ -987,27 +1138,73 @@ static void send_headers(int responseNum)
 #endif
 
        if (file_size != -1) {    /* file */
-               strftime(tmp_str, sizeof(tmp_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, "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
+                       len += sprintf(iobuf + len,
+                               "Content-Range: bytes %"OFF_FMT"u-%"OFF_FMT"u/%"OFF_FMT"u\r\n",
                                        range_start,
                                        range_end,
-                                       file_size);
+                                       file_size
+                       );
                        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",
-                               tmp_str,
-                               content_gzip ? "Transfer-length:" : "Content-length:",
+                       "Last-Modified: %s\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,
                                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");
 
@@ -1015,13 +1212,19 @@ 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%s\n</BODY></HTML>\n",
+                               "<HTML><HEAD><TITLE>%u %s</TITLE></HEAD>\n"
+                               "<BODY><H1>%u %s</H1>\n"
+                               "%s\n"
+                               "</BODY></HTML>\n",
                                responseNum, responseString,
-                               responseNum, responseString, infoString);
+                               responseNum, responseString,
+                               infoString
+               );
        }
-       if (DEBUG)
+       if (DEBUG) {
+               iobuf[len] = '\0';
                fprintf(stderr, "headers: '%s'\n", iobuf);
+       }
        if (full_write(STDOUT_FILENO, iobuf, len) != len) {
                if (verbose > 1)
                        bb_perror_msg("error");
@@ -1038,37 +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));
+                       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;
 }
 
@@ -1103,18 +1308,31 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
 
        /* NB: breaking out of this loop jumps to log_and_exit() */
        out_cnt = 0;
+       pfd[FROM_CGI].fd = fromCgi_rd;
+       pfd[FROM_CGI].events = POLLIN;
+       pfd[TO_CGI].fd = toCgi_wr;
        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;
+               /* Note: even pfd[0].events == 0 won't prevent
+                * revents == POLLHUP|POLLERR reports from closed stdin.
+                * Setting fd to -1 works: */
+               pfd[0].fd = -1;
+               pfd[0].events = POLLIN;
+               pfd[0].revents = 0; /* probably not needed, paranoia */
+
+               /* We always poll this fd, thus kernel always sets revents: */
+               /*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 :( */
+               /* http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47059 */
+               /* hopefully one day it will... */
+               pfd[TO_CGI].events = POLLOUT;
+               pfd[TO_CGI].revents = 0; /* needed! */
+
+               if (toCgi_wr && hdr_cnt <= 0) {
+                       if (post_len > 0) {
+                               /* Expect more POST data from network */
+                               pfd[0].fd = 0;
                        } else {
                                /* post_len <= 0 && hdr_cnt <= 0:
                                 * no more POST data to CGI,
@@ -1126,7 +1344,7 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
                }
 
                /* Now wait on the set of sockets */
-               count = safe_poll(pfd, toCgi_wr ? TO_CGI+1 : FROM_CGI+1, -1);
+               count = safe_poll(pfd, hdr_cnt > 0 ? TO_CGI+1 : FROM_CGI+1, -1);
                if (count <= 0) {
 #if 0
                        if (safe_waitpid(pid, &status, WNOHANG) <= 0) {
@@ -1135,15 +1353,15 @@ 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;
                }
 
                if (pfd[TO_CGI].revents) {
-                       /* hdr_cnt > 0 here due to the way pfd[TO_CGI].events set */
+                       /* hdr_cnt > 0 here due to the way poll() called */
                        /* 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
@@ -1164,9 +1382,9 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
                        /* 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 = post_len > (int)sizeof_hdr_buf ? (int)sizeof_hdr_buf : post_len;
                        //count = safe_read(STDIN_FILENO, hdr_buf, count);
-                       count = safe_read(STDIN_FILENO, hdr_buf, sizeof(hdr_buf));
+                       count = safe_read(STDIN_FILENO, hdr_buf, sizeof_hdr_buf);
                        if (count > 0) {
                                hdr_cnt = count;
                                hdr_ptr = hdr_buf;
@@ -1212,7 +1430,8 @@ static NOINLINE void cgi_io_loop_and_exit(int fromCgi_rd, int toCgi_wr, int post
                                        /* send "HTTP/1.0 " */
                                        if (full_write(STDOUT_FILENO, HTTP_200, 9) != 9)
                                                break;
-                                       rbuf += 8; /* skip "Status: " */
+                                       /* 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) {
@@ -1265,22 +1484,19 @@ static void setenv1(const char *name, const char *value)
  *
  * Parameters:
  * 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 */
@@ -1302,7 +1518,7 @@ static void send_cgi_and_exit(
        while ((script = strchr(script + 1, '/')) != NULL) {
                int dir;
                *script = '\0';
-               dir = is_directory(url + 1, /*followlinks:*/ 1, NULL);
+               dir = is_directory(url + 1, /*followlinks:*/ 1);
                *script = '/';
                if (!dir) {
                        /* not directory, found script.cgi/PATH_INFO */
@@ -1314,9 +1530,9 @@ static void send_cgi_and_exit(
        setenv1("PATH_INFO", script);   /* set to /PATH_INFO or "" */
        setenv1("REQUEST_METHOD", request);
        if (g_query) {
-               putenv(xasprintf("%s=%s?%s", "REQUEST_URI", url, g_query));
+               putenv(xasprintf("%s=%s?%s", "REQUEST_URI", orig_uri, g_query));
        } else {
-               setenv1("REQUEST_URI", url);
+               setenv1("REQUEST_URI", orig_uri);
        }
        if (script != NULL)
                *script = '\0';         /* cut off /PATH_INFO */
@@ -1358,26 +1574,14 @@ static void send_cgi_and_exit(
 #endif
                }
        }
-       setenv1("HTTP_USER_AGENT", user_agent);
-       if (http_accept)
-               setenv1("HTTP_ACCEPT", http_accept);
-       if (http_accept_language)
-               setenv1("HTTP_ACCEPT_LANGUAGE", 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 (referer)
-               setenv1("HTTP_REFERER", referer);
-       setenv1("HTTP_HOST", host); /* set to "" if NULL */
        /* setenv1("SERVER_NAME", safe_gethostname()); - don't do this,
         * just run "env SERVER_NAME=xyz httpd ..." instead */
 
@@ -1410,7 +1614,7 @@ static void send_cgi_and_exit(
                if (script != url) { /* paranoia */
                        *script = '\0';
                        if (chdir(url + 1) != 0) {
-                               bb_perror_msg("chdir(%s)", url + 1);
+                               bb_perror_msg("can't change directory to '%s'", url + 1);
                                goto error_execing_cgi;
                        }
                        // not needed: *script = '/';
@@ -1515,8 +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 =
@@ -1586,18 +1790,18 @@ static NOINLINE void send_file_and_exit(const char *url, int what)
        if (what == SEND_BODY /* err pages and ranges don't mix */
         || content_gzip /* we are sending compressed page: can't do ranges */  ///why?
        ) {
-               range_start = 0;
+               range_start = -1;
        }
        range_len = MAXINT(off_t);
-       if (range_start) {
-               if (!range_end) {
+       if (range_start >= 0) {
+               if (!range_end || range_end > file_size - 1) {
                        range_end = file_size - 1;
                }
                if (range_end < range_start
                 || lseek(fd, range_start, SEEK_SET) != range_start
                ) {
                        lseek(fd, 0, SEEK_SET);
-                       range_start = 0;
+                       range_start = -1;
                } else {
                        range_len = range_end - range_start + 1;
                        send_headers(HTTP_PARTIAL_CONTENT);
@@ -1607,7 +1811,7 @@ static NOINLINE void send_file_and_exit(const char *url, int what)
 #endif
        if (what & SEND_HEADERS)
                send_headers(HTTP_OK);
-#if ENABLE_FEATURE_HTTPD_USE_SENDFILE
+#if ENABLE_FEATURE_USE_SENDFILE
        {
                off_t offset = range_start;
                while (1) {
@@ -1620,7 +1824,7 @@ static NOINLINE void send_file_and_exit(const char *url, int what)
                                        break; /* fall back to read/write loop */
                                goto fin;
                        }
-                       IF_FEATURE_HTTPD_RANGES(range_len -= sz;)
+                       IF_FEATURE_HTTPD_RANGES(range_len -= count;)
                        if (count == 0 || range_len == 0)
                                log_and_exit();
                }
@@ -1637,14 +1841,14 @@ static NOINLINE void send_file_and_exit(const char *url, int what)
                        break;
        }
        if (count < 0) {
- IF_FEATURE_HTTPD_USE_SENDFILE(fin:)
+ IF_FEATURE_USE_SENDFILE(fin:)
                if (verbose > 1)
                        bb_perror_msg("error");
        }
        log_and_exit();
 }
 
-static int checkPermIP(void)
+static void if_ip_denied_send_HTTP_FORBIDDEN_and_exit(unsigned remote_ip)
 {
        Htaccess_IP *cur;
 
@@ -1663,16 +1867,20 @@ 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
 
-# if ENABLE_FEATURE_HTTPD_AUTH_MD5 && ENABLE_PAM
+# if ENABLE_PAM
 struct pam_userinfo {
        const char *name;
        const char *pw;
@@ -1704,9 +1912,9 @@ static int pam_talker(int num_msg,
                case PAM_PROMPT_ECHO_OFF:
                        s = userinfo->pw;
                        break;
-               case PAM_ERROR_MSG:
-               case PAM_TEXT_INFO:
-                       s = "";
+               case PAM_ERROR_MSG:
+               case PAM_TEXT_INFO:
+                       s = "";
                        break;
                default:
                        free(response);
@@ -1773,6 +1981,16 @@ static int check_user_passwd(const char *path, char *user_and_passwd)
                        colon_after_user = strchr(user_and_passwd, ':');
                        if (!colon_after_user)
                                goto bad_input;
+
+                       /* compare "user:" */
+                       if (cur->after_colon[0] != '*'
+                        && strncmp(cur->after_colon, user_and_passwd,
+                                       colon_after_user - user_and_passwd + 1) != 0
+                       ) {
+                               continue;
+                       }
+                       /* this cfg entry is '*' or matches username from peer */
+
                        passwd = strchr(cur->after_colon, ':');
                        if (!passwd)
                                goto bad_input;
@@ -1783,13 +2001,6 @@ static int check_user_passwd(const char *path, char *user_and_passwd)
                                struct pam_conv conv_info = { &pam_talker, (void *) &userinfo };
                                pam_handle_t *pamh;
 
-                               /* compare "user:" */
-                               if (cur->after_colon[0] != '*'
-                                && strncmp(cur->after_colon, user_and_passwd, colon_after_user - user_and_passwd + 1) != 0
-                               ) {
-                                       continue;
-                               }
-                               /* this cfg entry is '*' or matches username from peer */
                                *colon_after_user = '\0';
                                userinfo.name = user_and_passwd;
                                userinfo.pw = colon_after_user + 1;
@@ -1825,31 +2036,34 @@ static int check_user_passwd(const char *path, char *user_and_passwd)
                                                passwd = result->sp_pwdp;
                                }
 #  endif
+                               /* In this case, passwd is ALWAYS encrypted:
+                                * it came from /etc/passwd or /etc/shadow!
+                                */
+                               goto check_encrypted;
 # endif /* ENABLE_PAM */
                        }
+                       /* Else: passwd is from httpd.conf, it is either plaintext or encrypted */
 
-                       /* compare "user:" */
-                       if (cur->after_colon[0] != '*'
-                        && strncmp(cur->after_colon, user_and_passwd, colon_after_user - user_and_passwd + 1) != 0
-                       ) {
-                               continue;
-                       }
-                       /* this cfg entry is '*' or matches username from peer */
-
-                       /* encrypt pwd from peer and check match with local one */
-                       {
-                               char *encrypted = pw_encrypt(
-                                       /* pwd: */  colon_after_user + 1,
+                       if (passwd[0] == '$' && isdigit(passwd[1])) {
+                               char *encrypted;
+# if !ENABLE_PAM
+ check_encrypted:
+# endif
+                               /* encrypt pwd from peer and check match with local one */
+                               encrypted = pw_encrypt(
+                                       /* pwd (from peer): */  colon_after_user + 1,
                                        /* salt: */ passwd,
                                        /* cleanup: */ 0
                                );
                                r = strcmp(encrypted, passwd);
                                free(encrypted);
-                               goto end_check_passwd;
+                       } else {
+                               /* local passwd is from httpd.conf and it's plaintext */
+                               r = strcmp(colon_after_user + 1, passwd);
                        }
bad_input: ;
                      goto end_check_passwd;
                }
-
+ bad_input:
                /* Comparing plaintext "user:pass" in one go */
                r = strcmp(cur->after_colon, user_and_passwd);
  end_check_passwd:
@@ -1871,7 +2085,7 @@ static Htaccess_Proxy *find_proxy_entry(const char *url)
 {
        Htaccess_Proxy *p;
        for (p = proxy; p; p = p->next) {
-               if (strncmp(url, p->url_from, strlen(p->url_from)) == 0)
+               if (is_prefixed_with(url, p->url_from))
                        return p;
        }
        return NULL;
@@ -1898,12 +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;
@@ -1911,29 +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?) */
@@ -1946,6 +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);
@@ -1954,7 +2166,9 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
                send_headers_and_exit(HTTP_BAD_REQUEST);
 
        /* Determine type of request (GET/POST) */
-       urlp = strpbrk(iobuf, " \t");
+       // rfc2616: method and URI is separated by exactly one space
+       //urlp = strpbrk(iobuf, " \t"); - no, tab isn't allowed
+       urlp = strchr(iobuf, ' ');
        if (urlp == NULL)
                send_headers_and_exit(HTTP_BAD_REQUEST);
        *urlp++ = '\0';
@@ -1972,35 +2186,64 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
        if (strcasecmp(iobuf, request_GET) != 0)
                send_headers_and_exit(HTTP_NOT_IMPLEMENTED);
 #endif
-       urlp = skip_whitespace(urlp);
+       // rfc2616: method and URI is separated by exactly one space
+       //urlp = skip_whitespace(urlp); - should not be necessary
        if (urlp[0] != '/')
                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);
@@ -2040,7 +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++;
@@ -2048,7 +2291,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 
        /* If URL is a directory, add '/' */
        if (urlp[-1] != '/') {
-               if (is_directory(urlcopy + 1, 1, NULL)) {
+               if (is_directory(urlcopy + 1, /*followlinks:*/ 1)) {
                        found_moved_temporarily = urlcopy;
                }
        }
@@ -2058,59 +2301,97 @@ 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, 1, NULL)) {
+               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 - 2) {
-                               int len = strlen(iobuf);
-                               if (len > IOBUF_SIZE - (header_ptr - header_buf) - 4)
-                                       len = 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
                                 && prequest != request_HEAD
 # endif
                                ) {
-                                       tptr = skip_whitespace(iobuf + sizeof("Content-length:") - 1);
+                                       tptr = skip_whitespace(iobuf + sizeof("Content-Length:") - 1);
                                        if (!tptr[0])
                                                send_headers_and_exit(HTTP_BAD_REQUEST);
                                        /* not using strtoul: it ignores leading minus! */
@@ -2119,23 +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) {
-                               cookie = xstrdup(skip_whitespace(iobuf + sizeof("Cookie:")-1));
-                       } else if (STRNCASECMP(iobuf, "Content-Type:") == 0) {
-                               content_type = xstrdup(skip_whitespace(iobuf + sizeof("Content-Type:")-1));
-                       } else if (STRNCASECMP(iobuf, "Referer:") == 0) {
-                               referer = xstrdup(skip_whitespace(iobuf + sizeof("Referer:")-1));
-                       } else if (STRNCASECMP(iobuf, "User-Agent:") == 0) {
-                               user_agent = xstrdup(skip_whitespace(iobuf + sizeof("User-Agent:")-1));
-                       } else if (STRNCASECMP(iobuf, "Host:") == 0) {
-                               host = xstrdup(skip_whitespace(iobuf + sizeof("Host:")-1));
-                       } else if (STRNCASECMP(iobuf, "Accept:") == 0) {
-                               http_accept = xstrdup(skip_whitespace(iobuf + sizeof("Accept:")-1));
-                       } else if (STRNCASECMP(iobuf, "Accept-Language:") == 0) {
-                               http_accept_language = xstrdup(skip_whitespace(iobuf + sizeof("Accept-Language:")-1));
+                               continue;
                        }
 #endif
 #if ENABLE_FEATURE_HTTPD_BASIC_AUTH
@@ -2145,29 +2410,31 @@ 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 (strncmp(s, "bytes=", 6) == 0) {
+                               if (is_prefixed_with(s, "bytes=")) {
                                        s += sizeof("bytes=")-1;
                                        range_start = BB_STRTOOFF(s, &s, 10);
                                        if (s[0] != '-' || range_start < 0) {
-                                               range_start = 0;
+                                               range_start = -1;
                                        } else if (s[1]) {
                                                range_end = BB_STRTOOFF(s+1, NULL, 10);
                                                if (errno || range_end < range_start)
-                                                       range_start = 0;
+                                                       range_start = -1;
                                        }
                                }
+                               continue;
                        }
 #endif
 #if ENABLE_FEATURE_HTTPD_GZIP
@@ -2185,6 +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 */
@@ -2193,7 +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);
        }
@@ -2211,76 +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;
-
-               proxy_fd = socket(AF_INET, SOCK_STREAM, 0);
-               if (proxy_fd < 0)
-                       send_headers_and_exit(HTTP_INTERNAL_SERVER_ERROR);
-               lsa = host2sockaddr(proxy_entry->host_port, 80);
-               if (lsa == NULL)
-                       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 (strncmp(tptr, "cgi-bin/", 8) == 0) {
-               if (tptr[8] == '\0') {
-                       /* protect listing "cgi-bin/" */
-                       send_headers_and_exit(HTTP_FORBIDDEN);
-               }
-               send_cgi_and_exit(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] == '/')
+       if (urlp[-1] == '/') {
                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, 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';
-                       g_query = urlcopy;
-                       send_cgi_and_exit("/cgi-bin/index.cgi", 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);
@@ -2319,7 +2562,7 @@ static void mini_httpd(int server_socket)
                        continue;
 
                /* set the KEEPALIVE option to cull dead connections */
-               setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
+               setsockopt_keepalive(n);
 
                if (fork() == 0) {
                        /* child */
@@ -2353,16 +2596,14 @@ 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;
 
                /* set the KEEPALIVE option to cull dead connections */
-               setsockopt(n, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
+               setsockopt_keepalive(n);
 
                if (vfork() == 0) {
                        /* child */
@@ -2401,7 +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 {
@@ -2449,17 +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)
@@ -2542,7 +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 */