diff -urN atftp-0.7.dfsg/atftpd.8 atftp-0.7.dfsg.patched/atftpd.8 --- atftp-0.7.dfsg/atftpd.8 2004-02-13 05:03:12.000000000 +0100 +++ atftp-0.7.dfsg.patched/atftpd.8 2009-04-16 19:30:15.000000000 +0200 @@ -161,6 +161,15 @@ printout the substitution. .TP +.B \-\-content\-generator +Execute to generate content for nonexisting files. If a +requested file does not exist, the program will be called as +--file . The generated contents must be written to +file descriptor 3, which will be opened by atftpd using tmpfile(). +If the contents need to be stored as well, the program itself is +responsible for doing so, atftpd will not store the contents. + +.TP .B \-\-mtftp This will start a mtftp server thread for each valid entry in the supplied file. See PXE specification for detail about mtftp. An diff -urN atftp-0.7.dfsg/configure.ac atftp-0.7.dfsg.patched/configure.ac --- atftp-0.7.dfsg/configure.ac 2004-03-16 02:51:40.000000000 +0100 +++ atftp-0.7.dfsg.patched/configure.ac 2009-04-13 22:36:36.000000000 +0200 @@ -45,6 +45,12 @@ yes) libpcre=true ;; no) libpcre=flase ;; esac], [libpcre=true]) +AC_ARG_ENABLE(generated_content, + [ --enable-generated-content enable support for generated content in the server], + [ case "${enableval}" in + yes) generated_content=true ;; + no) generated_content=false ;; + esac], [generated_content=false]) AC_ARG_ENABLE(mtftp, [ --enable-mtftp enable mtftp support in server], @@ -170,6 +176,10 @@ "Support for libpcre pattern subsitution")]) AC_SUBST(LIBPCRE) fi +if test x$generated_content = xtrue; then + AC_DEFINE([HAVE_GENERATED_CONTENT], 1, + Support for generated content) +fi dnl Checks for header files. AC_HEADER_STDC diff -urN atftp-0.7.dfsg/debian/rules atftp-0.7.dfsg.patched/debian/rules --- atftp-0.7.dfsg/debian/rules 2009-04-16 19:48:47.000000000 +0200 +++ atftp-0.7.dfsg.patched/debian/rules 2009-04-13 22:36:36.000000000 +0200 @@ -17,7 +17,7 @@ configure-stamp: dh_testdir # Add here commands to configure the package. - ./configure --prefix=/usr --mandir=/usr/share/man + ./configure --prefix=/usr --mandir=/usr/share/man --enable-generated-content touch configure-stamp diff -urN atftp-0.7.dfsg/README.GENERATED atftp-0.7.dfsg.patched/README.GENERATED --- atftp-0.7.dfsg/README.GENERATED 1970-01-01 01:00:00.000000000 +0100 +++ atftp-0.7.dfsg.patched/README.GENERATED 2009-04-16 19:36:56.000000000 +0200 @@ -0,0 +1,61 @@ +Dynamically generating content with atftpd +------------------------------------------ + +When installing many machines via PXEboot kickstart/d-i installs, it is often +useful to generate pxelinux.cfg files on demand with contents grabbed from a +database. Or when you have an Asus Wl500g router, you have only tftp available +to download data, being able to generate this data could be useful (eg. lists +of macaddresses or iptables rules). + +These were my two use cases for implementing support for dynamic content in +atftpd. Here is how to use it: + +* Add the "--content-generator /path/to/executable" argument to the atftpd + commandline (eg. in xinetd.conf or /etc/default/atftpd, depending on your + setup). +* Whenever a requested file cannot be found, atftpd will open a temporary + file with tmpfile(3) and will execute your application, with the + requested name as arguments (example: + /usr/local/bin/tftp-generator --file /var/lib/tftpboot/some_file) + The application must ignore unknown arguments, more arguments might be added + later. +* Your application is now responsible for writing the content that atftpd + should send to the given fd (6 in the example). If the content needs to + be stored, your application also must do so itself. +* If your application exists with a non-zero exitstatus or writes zero bytes, + atftpd will treat that as "file not found". If data is written and your + application exits with code 0, the written data is sent to the client. + +-- +Dennis Kaarsemaker + + +------------------------------------------------------------------------------- +Example application for use case #2: Grabbing a list of mac addresses from a +database. The database is maintained using the django framework. + +#!/usr/bin/python + +import os +import sys +from optparse import OptionParser + +parser = OptionParser() +parser.add_option("--file", dest="filename", help="Requested file", metavar="FILE") +options, args = parser.parse_args() + +if os.path.basename(options.filename) != 'maclist': + sys.exit(1) +fd = os.fdopen(3, 'w') + +sys.path.insert(0,'/srv/www/intranet') +os.environ['DJANGO_SETTINGS_MODULE'] = 'infra.settings' +from infra.machine.models import Interface + +fd.write("""#!/bin/sh +# Shellscript generated from infra database +# Do not edit by hand + +wl mac none +wl mac %s 00:00:00:00:00:00 +""" % ' '.join([x.mac for x in Interface.objects.filter(wireless=True)])) diff -urN atftp-0.7.dfsg/redhat/atftp.spec.in atftp-0.7.dfsg.patched/redhat/atftp.spec.in --- atftp-0.7.dfsg/redhat/atftp.spec.in 2003-04-29 02:36:58.000000000 +0200 +++ atftp-0.7.dfsg.patched/redhat/atftp.spec.in 2009-04-16 19:50:41.000000000 +0200 @@ -33,7 +33,7 @@ %build -%configure +%configure --enable-generated-files make diff -urN atftp-0.7.dfsg/tftpd.c atftp-0.7.dfsg.patched/tftpd.c --- atftp-0.7.dfsg/tftpd.c 2009-04-16 19:48:47.000000000 +0200 +++ atftp-0.7.dfsg.patched/tftpd.c 2009-04-13 22:36:36.000000000 +0200 @@ -112,6 +112,10 @@ char *pcre_file; #endif +#ifdef HAVE_GENERATED_CONTENT +char *content_generator = NULL; +#endif + #ifdef HAVE_MTFTP /* mtftp options */ struct mtftp_data *mtftp_data = NULL; @@ -839,6 +843,9 @@ { "pcre", 1, NULL, OPT_PCRE }, { "pcre-test", 1, NULL, OPT_PCRE_TEST }, #endif +#ifdef HAVE_GENERATED_CONTENT + { "content-generator", 1, NULL, 'g' }, +#endif #ifdef HAVE_MTFTP { "mtftp", 1, NULL, OPT_MTFTP }, { "mtftp-port", 1, NULL, OPT_MTFTP_PORT }, @@ -968,6 +975,15 @@ printf("Substitution: \"%s\" -> \"%s\"\n", string, out); } #endif +#ifdef HAVE_GENERATED_CONTENT + case 'g': + content_generator = strdup(optarg); + if(access(content_generator, X_OK)) { + fprintf(stderr, "Cannot use %s as content generator: %s\n", content_generator, strerror(errno)); + content_generator = NULL; + } + break; +#endif case OPT_PORT_CHECK: source_port_checking = 0; break; @@ -1053,6 +1069,10 @@ if (pcre_top) logger(LOG_INFO, " PCRE: using file: %s", pcre_file); #endif +#ifdef HAVE_GENERATED_CONTENT + if(content_generator) + logger(LOG_INFO, " content generator: %s", content_generator); +#endif #ifdef HAVE_MTFTP if (strcmp(mtftp_file, "") != 0) { @@ -1142,6 +1162,9 @@ " --pcre : use this file for pattern replacement\n" " --pcre-test : just test pattern file, not starting server\n" #endif +#ifdef HAVE_GENERATED_CONTENT + " --content-generator : use to generate content\n" +#endif #ifdef HAVE_MTFTP " --mtftp : mtftp configuration file\n" " --mtftp-port : port mtftp will listen\n" diff -urN atftp-0.7.dfsg/tftpd_file.c atftp-0.7.dfsg.patched/tftpd_file.c --- atftp-0.7.dfsg/tftpd_file.c 2004-02-18 03:21:47.000000000 +0100 +++ atftp-0.7.dfsg.patched/tftpd_file.c 2009-04-16 19:14:25.000000000 +0200 @@ -36,6 +36,10 @@ #ifdef HAVE_PCRE #include "tftpd_pcre.h" #endif +#ifdef HAVE_GENERATED_CONTENT +#include +#include +#endif #define S_BEGIN 0 #define S_SEND_REQ 1 @@ -60,6 +64,9 @@ extern tftpd_pcre_self_t *pcre_top; #endif +#ifdef HAVE_GENERATED_CONTENT +extern char* content_generator; +#endif /* * Rules for filenames. This is common to both tftpd_recieve_file @@ -428,6 +435,10 @@ int prev_block_number = 0; /* needed to support netascii convertion */ int prev_file_pos = 0; int temp = 0; +#ifdef HAVE_GENERATED_CONTENT + pid_t generator_pid = 0; + int generator_status; +#endif /* look for mode option */ if (strcasecmp(data->tftp_options[OPT_MODE].value, "netascii") == 0) @@ -485,6 +496,56 @@ } } #endif +#ifdef HAVE_GENERATED_CONTENT + if (fp == NULL) + { + if (content_generator) + { + logger(LOG_DEBUG, "Trying to generate contents for %s", filename); + fp = tmpfile(); + generator_pid = fork(); + switch(generator_pid) { + case 0: + /* In the child */ + close(3); + dup2(fileno(fp), 3); + for(temp=4; temp < 1024; temp++) + close(temp); + execl(content_generator, content_generator, "--file", filename, (char *)NULL); + /* Exec failed, make sure the parent notices */ + exit(66); + ;; + case -1: + logger(LOG_WARNING, "fork() failed: %s", strerror(errno)); + fclose(fp); + fp = NULL; + default: + /* In the parent */ + while(1) { + errno = 0; + temp = waitpid(generator_pid, &generator_status, 0); + if(temp == -1 && errno == EINTR) + continue; + break; + } + if(!WIFEXITED(generator_status) || (WEXITSTATUS(generator_status) != 0)) { + logger(LOG_WARNING, "generating content failed: %d %d", generator_status, WEXITSTATUS(generator_status)); + fclose(fp); + fp = NULL; + } + else { + fstat(fileno(fp), &file_stat); + if(file_stat.st_size == 0) { + logger(LOG_WARNING, "content generator wrote 0 bytes"); + fclose(fp); + fp = NULL; + } + } + break; + } + } + } +#endif if (fp == NULL) { tftp_send_error(sockfd, sa, ENOTFOUND, data->data_buffer, data->data_buffer_size);