stunnel-4.41-xforwarded-for.diff

stunnel-4.41-xforwarded-for.diff (text/plain), 10.75 KB, created by Marcel Pennewiß on 2011-08-02 19:50:00 UTC

diff -urN stunnel-4.41/doc/stunnel.8 stunnel-4.41-new//doc/stunnel.8
--- stunnel-4.41/doc/stunnel.8	2011-08-01 22:20:02.000000000 +0200
+++ stunnel-4.41-new//doc/stunnel.8	2011-08-01 22:29:42.198257030 +0200
@@ -578,6 +578,10 @@
 .IP "\fBTIMEOUTidle\fR = seconds" 4
 .IX Item "TIMEOUTidle = seconds"
 time to keep an idle connection
+.IP "\fBxforwardedfor\fR = yes | no" 4
+.IX Item "xforwardedfor = yes | no"
+append an 'X-Forwarded-For:' HTTP request header providing the
+client's IP address to the server.
 .IP "\fBtransparent\fR = none | source | destination | both (Unix only)" 4
 .IX Item "transparent = none | source | destination | both (Unix only)"
 enable transparent proxy support on selected platforms
diff -urN stunnel-4.41/doc/stunnel.fr.8 stunnel-4.41-new//doc/stunnel.fr.8
--- stunnel-4.41/doc/stunnel.fr.8	2011-08-01 22:20:02.000000000 +0200
+++ stunnel-4.41-new//doc/stunnel.fr.8	2011-08-01 22:29:42.201588420 +0200
@@ -392,6 +392,10 @@
 .IP "\fBTIMEOUTidle\fR = secondes" 4
 .IX Item "TIMEOUTidle = secondes"
 Durée d'attente sur une connexion inactive
+.IP "\fBxforwardedfor\fR = yes | no" 4
+.IX Item "xforwardedfor = yes | no"
+Ajoute un en-tête 'X-Forwarded-For:' dans la requête HTTP fournissant
+au serveur l'adresse IP du client.
 .IP "\fBtransparent\fR = yes | no (Unix seulement)" 4
 .IX Item "transparent = yes | no (Unix seulement)"
 Mode mandataire transparent
diff -urN stunnel-4.41/src/client.c stunnel-4.41-new//src/client.c
--- stunnel-4.41/src/client.c	2011-08-01 22:20:02.000000000 +0200
+++ stunnel-4.41-new//src/client.c	2011-08-01 22:29:42.204922884 +0200
@@ -81,6 +81,12 @@
     }
     str_detach(c);
     c->opt=opt;
+    /* some options need space to add some information */
+    if (c->opt->option.xforwardedfor)
+        c->buffsize = BUFFSIZE - BUFF_RESERVED;
+    else
+        c->buffsize = BUFFSIZE;
+    c->crlf_seen=0;
     c->local_rfd.fd=rfd;
     c->local_wfd.fd=wfd;
     return c;
@@ -383,6 +389,28 @@
     }
 }
 
+/* Moves all data from the buffer <buffer> between positions <start> and <stop>
+ * to insert <string> of length <len>. <start> and <stop> are updated to their
+ * new respective values, and the number of characters inserted is returned.
+ * If <len> is too long, nothing is done and -1 is returned.
+ * Note that neither <string> nor <buffer> can be NULL.
+ */
+static int buffer_insert_with_len(char *buffer, int *start, int *stop, int limit, char *string, int len) {
+    if (len > limit - *stop)
+        return -1;
+    if (*start > *stop)
+        return -1;
+    memmove(buffer + *start + len, buffer + *start, *stop - *start);
+    memcpy(buffer + *start, string, len);
+    *start += len;
+    *stop += len;
+    return len;
+}
+
+static int buffer_insert(char *buffer, int *start, int *stop, int limit, char *string) {
+    return buffer_insert_with_len(buffer, start, stop, limit, string, strlen(string));
+}
+
 /****************************** transfer data */
 static void transfer(CLI *c) {
     int watchdog=0; /* a counter to detect an infinite loop */
@@ -401,7 +429,7 @@
     do { /* main loop of client data transfer */
         /****************************** initialize *_wants_* */
         read_wants_read=
-            ssl_open_rd && c->ssl_ptr<BUFFSIZE && !read_wants_write;
+            ssl_open_rd && c->ssl_ptr<c->buffsize && !read_wants_write;
         write_wants_write=
             ssl_open_wr && c->sock_ptr && !write_wants_read;
 
@@ -410,7 +438,7 @@
         /* for plain socket open data strem = open file descriptor */
         /* make sure to add each open socket to receive exceptions! */
         if(sock_open_rd)
-            s_poll_add(&c->fds, c->sock_rfd->fd, c->sock_ptr<BUFFSIZE, 0);
+            s_poll_add(&c->fds, c->sock_rfd->fd, c->sock_ptr<c->buffsize, 0);
         if(sock_open_wr)
             s_poll_add(&c->fds, c->sock_wfd->fd, 0, c->ssl_ptr);
         /* for SSL assume that sockets are open if there any pending requests */
@@ -544,7 +572,7 @@
         /****************************** read from socket */
         if(sock_open_rd && sock_can_rd) {
             num=readsocket(c->sock_rfd->fd,
-                c->sock_buff+c->sock_ptr, BUFFSIZE-c->sock_ptr);
+                c->sock_buff+c->sock_ptr, c->buffsize-c->sock_ptr);
             switch(num) {
             case -1:
                 parse_socket_error(c, "readsocket");
@@ -580,7 +608,7 @@
         /****************************** update *_wants_* based on new *_ptr */
         /* this update is also required for SSL_pending() to be used */
         read_wants_read=
-            ssl_open_rd && c->ssl_ptr<BUFFSIZE && !read_wants_write;
+            ssl_open_rd && c->ssl_ptr<c->buffsize && !read_wants_write;
         write_wants_write=
             ssl_open_wr && c->sock_ptr && !write_wants_read;
 
@@ -590,10 +618,71 @@
                  * writesocket() above made some room in c->ssl_buff */
                 (read_wants_write && ssl_can_wr)) {
             read_wants_write=0;
-            num=SSL_read(c->ssl, c->ssl_buff+c->ssl_ptr, BUFFSIZE-c->ssl_ptr);
+            num=SSL_read(c->ssl, c->ssl_buff+c->ssl_ptr, c->buffsize-c->ssl_ptr);
             switch(err=SSL_get_error(c->ssl, num)) {
             case SSL_ERROR_NONE:
-                c->ssl_ptr+=num;
+                if (c->buffsize != BUFFSIZE && c->opt->option.xforwardedfor) { /* some work left to do */
+                    int last = c->ssl_ptr;
+                    c->ssl_ptr += num;
+
+                    /* Look for end of HTTP headers between last and ssl_ptr.
+                    * To achieve this reliably, we have to count the number of
+                    * successive [CR]LF and to memorize it in case it's spread
+                    * over multiple segments. --WT.
+                    */
+                    while (last < c->ssl_ptr) {
+                        if (c->ssl_buff[last] == '\n') {
+                            if (++c->crlf_seen == 2)
+                                break;
+                        } else if (last < c->ssl_ptr - 1 &&
+                                    c->ssl_buff[last] == '\r' &&
+                                    c->ssl_buff[last+1] == '\n') {
+                            if (++c->crlf_seen == 2)
+                                break;
+                            last++;
+                        } else if (c->ssl_buff[last] != '\r')
+                            /* don't refuse '\r' because we may get a '\n' on next read */
+                            c->crlf_seen = 0;
+                        last++;
+                    }
+                    if (c->crlf_seen >= 2) {
+                        /* We have all the HTTP headers now. We don't need to
+                        * reserve any space anymore. <ssl_ptr> points to the
+                        * first byte of unread data, and <last> points to the
+                        * exact location where we want to insert our headers,
+                        * which is right before the empty line.
+                        */
+                        c->buffsize = BUFFSIZE;
+
+                        if (c->opt->option.xforwardedfor) {
+                            /* X-Forwarded-For: xxxx \r\n\0 */
+                            char xforw[17 + IPLEN + 3];
+
+                            /* We will insert our X-Forwarded-For: header here.
+                            * We need to write the IP address, but if we use
+                            * sprintf, it will pad with the terminating 0.
+                            * So we will pass via a temporary buffer allocated
+                            * on the stack.
+                            */
+                            memcpy(xforw, "X-Forwarded-For: ", 17);
+                            if (getnameinfo(&c->peer_addr.addr[0].sa,
+                                    addr_len(c->peer_addr.addr[0]),
+                                    xforw + 17, IPLEN, NULL, 0,
+                                    NI_NUMERICHOST) == 0) {
+                                strcat(xforw + 17, "\r\n");
+                                buffer_insert(c->ssl_buff, &last, &c->ssl_ptr,
+                                            c->buffsize, xforw);
+                            }
+                            /* last still points to the \r\n and ssl_ptr to the
+                            * end of the buffer, so we may add as many headers
+                            * as wee need to.
+                            */
+                        }
+                    }
+                }
+                else
+                   c->ssl_ptr+=num;
+
                 watchdog=0; /* reset watchdog */
                 break;
             case SSL_ERROR_WANT_WRITE:
diff -urN stunnel-4.41/src/common.h stunnel-4.41-new//src/common.h
--- stunnel-4.41/src/common.h	2011-08-01 22:20:02.000000000 +0200
+++ stunnel-4.41-new//src/common.h	2011-08-01 22:29:42.250885862 +0200
@@ -52,6 +52,9 @@
 /* I/O buffer size */
 #define BUFFSIZE 16384
 
+/* maximum space reserved for header insertion in BUFFSIZE */
+#define BUFF_RESERVED 1024
+
 /* IP address and TCP port textual representation length */
 #define IPLEN 128
 
diff -urN stunnel-4.41/src/options.c stunnel-4.41-new//src/options.c
--- stunnel-4.41/src/options.c	2011-08-01 22:20:02.000000000 +0200
+++ stunnel-4.41-new//src/options.c	2011-08-01 22:29:42.254923424 +0200
@@ -831,6 +831,29 @@
     }
 #endif
 
+    /* xforwardedfor */
+    switch(cmd) {
+    case CMD_INIT:
+        section->option.xforwardedfor=0;
+        break;
+    case CMD_EXEC:
+        if(strcasecmp(opt, "xforwardedfor"))
+            break;
+        if(!strcasecmp(arg, "yes"))
+            section->option.xforwardedfor=1;
+        else if(!strcasecmp(arg, "no"))
+            section->option.xforwardedfor=0;
+        else
+            return "argument should be either 'yes' or 'no'";
+        return NULL; /* OK */
+    case CMD_DEFAULT:
+        break;
+    case CMD_HELP:
+        s_log(LOG_NOTICE, "%-15s = yes|no append an HTTP X-Forwarded-For header",
+            "xforwardedfor");
+        break;
+    }
+
     /* exec */
     switch(cmd) {
     case CMD_INIT:
diff -urN stunnel-4.41/src/prototypes.h stunnel-4.41-new//src/prototypes.h
--- stunnel-4.41/src/prototypes.h	2011-08-01 22:20:02.000000000 +0200
+++ stunnel-4.41-new//src/prototypes.h	2011-08-01 22:29:42.258256280 +0200
@@ -184,6 +184,7 @@
         unsigned int accept:1;          /* endpoint: accept */
         unsigned int client:1;
         unsigned int delayed_lookup:1;
+        unsigned int xforwardedfor:1;
 #ifdef USE_LIBWRAP
         unsigned int libwrap:1;
 #endif
@@ -386,6 +387,8 @@
     FD *ssl_rfd, *ssl_wfd; /* read and write SSL descriptors */
     int sock_bytes, ssl_bytes; /* bytes written to socket and SSL */
     s_poll_set fds; /* file descriptors */
+    int buffsize;  /* current buffer size, may be lower than BUFFSIZE */
+    int crlf_seen; /* the number of successive CRLF seen */
 } CLI;
 
 CLI *alloc_client_session(SERVICE_OPTIONS *, int, int);