diff options
Diffstat (limited to 'networking')
| -rw-r--r-- | networking/Config.in | 30 | ||||
| -rw-r--r-- | networking/sendmail.c | 181 |
2 files changed, 90 insertions, 121 deletions
diff --git a/networking/Config.in b/networking/Config.in index 202b65f..3c53c11 100644 --- a/networking/Config.in +++ b/networking/Config.in @@ -678,39 +678,11 @@ config SENDMAIL help Barebones sendmail. -config FEATURE_SENDMAIL_EHLO - bool "Support EHLO command" - default n - depends on SENDMAIL - help - Support ESMTP EHLO command. - -config FEATURE_SENDMAIL_BLOATY - bool "Be more verbose" - default n - depends on SENDMAIL - help - Should be turned off. - config FETCHMAIL bool "fetchmail" default n help - Barebone fetchmail. - -config FEATURE_FETCHMAIL_APOP - bool "Support APOP authentication" - default y - depends on FETCHMAIL - help - Support secure APOP authentication. - -config FEATURE_FETCHMAIL_FILTER - bool "Pipe through external filter" - default n - depends on FETCHMAIL - help - Support piping incoming messages through external filter. + Barebones fetchmail. config SLATTACH bool "slattach" diff --git a/networking/sendmail.c b/networking/sendmail.c index adc6c76..3a6078f 100644 --- a/networking/sendmail.c +++ b/networking/sendmail.c @@ -63,20 +63,13 @@ static void uuencode(char *fname, const char *text) close(fd); } -static const char *const init_xargs[9] = { - "openssl", "s_client", "-quiet", "-connect", - NULL, "-tls1", "-starttls", "smtp" -}; - struct globals { pid_t helper_pid; unsigned timeout; // arguments for SSL connection helper const char *xargs[9]; -#if ENABLE_FEATURE_FETCHMAIL_FILTER // arguments for postprocess helper const char *fargs[3]; -#endif }; #define G (*ptr_to_globals) #define helper_pid (G.helper_pid) @@ -85,16 +78,21 @@ struct globals { #define fargs (G.fargs ) #define INIT_G() do { \ PTR_TO_GLOBALS = xzalloc(sizeof(G)); \ - memcpy(xargs, init_xargs, sizeof(init_xargs)); \ + xargs[0] = "openssl"; \ + xargs[1] = "s_client"; \ + xargs[2] = "-quiet"; \ + xargs[3] = "-connect"; \ + /*xargs[4] = "server[:port]";*/ \ + xargs[5] = "-tls1"; \ + xargs[6] = "-starttls"; \ + xargs[7] = "smtp"; \ fargs[0] = "utf-8"; \ } while (0) #define opt_connect (xargs[4]) #define opt_after_connect (xargs[5]) -#if ENABLE_FEATURE_FETCHMAIL_FILTER #define opt_charset (fargs[0]) #define opt_subject (fargs[1]) -#endif static void kill_helper(void) { @@ -116,11 +114,7 @@ static void signal_handler(int signo) // SIGCHLD. reap zombies if (wait_any_nohang(&err) > 0) if (WIFEXITED(err) && WEXITSTATUS(err)) -#if ENABLE_FEATURE_SENDMAIL_BLOATY bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err)); -#else - bb_error_msg_and_die("child failed"); -#endif } static void launch_helper(const char **argv) @@ -141,12 +135,11 @@ static void launch_helper(const char **argv) if (pipes[i] > STDOUT_FILENO) close(pipes[i]); if (!helper_pid) { - // child - try to execute connection helper -// close(STDERR_FILENO); + // child: try to execute connection helper BB_EXECVP(*argv, (char **)argv); _exit(127); } - // parent - check whether child is alive + // parent: check whether child is alive bb_signals(0 + (1 << SIGCHLD) + (1 << SIGALRM) @@ -155,13 +148,12 @@ static void launch_helper(const char **argv) // child seems OK -> parent goes on } -static char *command(const char *fmt, const char *param) +static const char *command(const char *fmt, const char *param) { - char *msg = (char *)fmt; + const char *msg = fmt; alarm(timeout); if (msg) { -// if (param) - msg = xasprintf(fmt, param); + msg = xasprintf(fmt, param); printf("%s\r\n", msg); } fflush(stdout); @@ -171,25 +163,20 @@ static char *command(const char *fmt, const char *param) static int smtp_checkp(const char *fmt, const char *param, int code) { char *answer; - char *msg = command(fmt, param); + const char *msg = command(fmt, param); // read stdin // if the string has a form \d\d\d- -- read next string. E.g. EHLO response // parse first bytes to a number // if code = -1 then just return this number // if code != -1 then checks whether the number equals the code // if not equal -> die saying msg -#if ENABLE_FEATURE_SENDMAIL_EHLO while ((answer = xmalloc_getline(stdin)) != NULL) if (strlen(answer) <= 3 || '-' != answer[3]) break; -#else - answer = xmalloc_getline(stdin); -#endif if (answer) { int n = atoi(answer); alarm(0); if (ENABLE_FEATURE_CLEAN_UP) { - free(msg); free(answer); } if (-1 == code || n == code) { @@ -200,7 +187,7 @@ static int smtp_checkp(const char *fmt, const char *param, int code) bb_error_msg_and_die("%s failed", msg); } -static int smtp_check(const char *fmt, int code) +static int inline smtp_check(const char *fmt, int code) { return smtp_checkp(fmt, NULL, code); } @@ -223,7 +210,7 @@ static char *sane(char *str) #if ENABLE_FETCHMAIL static void pop3_checkr(const char *fmt, const char *param, char **ret) { - char *msg = command(fmt, param); + const char *msg = command(fmt, param); char *answer = xmalloc_getline(stdin); if (answer && '+' == *answer) { alarm(0); @@ -237,7 +224,7 @@ static void pop3_checkr(const char *fmt, const char *param, char **ret) bb_error_msg_and_die("%s failed", msg); } -static void pop3_check(const char *fmt, const char *param) +static void inline pop3_check(const char *fmt, const char *param) { pop3_checkr(fmt, param, NULL); } @@ -249,7 +236,7 @@ static void pop3_message(const char *filename) // create and open file filename // read stdin, copy to created file fd = xopen(filename, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL); - while ((answer = xmalloc_fgets_str(stdin, "\r\n"))) { + while ((answer = xmalloc_fgets_str(stdin, "\r\n")) != NULL) { char *s = answer; if ('.' == *answer) { if ('.' == answer[1]) @@ -268,10 +255,6 @@ int sendgetmail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int sendgetmail_main(int argc, char **argv) { llist_t *opt_recipients = NULL; -#if !ENABLE_FEATURE_FETCHMAIL_FILTER - char *opt_subject; - char *opt_charset = (char *)"utf-8"; -#endif const char *opt_user; const char *opt_pass; @@ -295,8 +278,12 @@ int sendgetmail_main(int argc, char **argv) const char *options; unsigned opts; + // init global variables INIT_G(); + // parse options, different option sets for sendmail and fetchmail + // N.B. opt_after_connect hereafter is NULL if we are called as fetchmail + // and is NOT NULL if we are called as sendmail if (!ENABLE_FETCHMAIL || 's' == applet_name[0]) { // SENDMAIL // save initial stdin (body or attachements can be piped!) @@ -313,7 +300,6 @@ int sendgetmail_main(int argc, char **argv) &timeout, &opt_user, &opt_pass, &opt_subject, &opt_charset, &opt_recipients ); - //argc -= optind; argv += optind; @@ -321,20 +307,29 @@ int sendgetmail_main(int argc, char **argv) opt_connect = *argv++; // connect to server + // SSL ordered? -> if (opts & OPT_X) { + // ... use openssl helper launch_helper(xargs); + // no SSL ordered? -> } else { - // no connection helper provided -> make plain connect - int fd = create_and_connect_stream_or_die(opt_connect, 0); + // ... make plain connect + int fd = create_and_connect_stream_or_die(opt_connect, 25); + // make ourselves a simple IO filter + // from now we know nothing about network :) xmove_fd(fd, STDIN_FILENO); xdup2(STDIN_FILENO, STDOUT_FILENO); } #if ENABLE_FETCHMAIL + // we are sendmail? if (opt_after_connect) #endif { - // SENDMAIL +/*************************************************** + * SENDMAIL + ***************************************************/ + char *opt_from; int code; char *boundary; @@ -342,44 +337,45 @@ int sendgetmail_main(int argc, char **argv) const char *p; char *q; - // wait for initial OK on plain connect - if (!(opts & OPT_X)) + // we didn't use SSL helper? -> + if (!(opts & OPT_X)) { + // ... wait for initial server OK smtp_check(NULL, 220); + } - // get specified sender + // get the sender opt_from = sane(*argv++); // introduce to server - // should we respect modern (but useless here) EHLO? - // or should they respect we wanna be tiny?! - if (!ENABLE_FEATURE_SENDMAIL_EHLO || 250 != smtp_checkp("EHLO %s", opt_from, -1)) { + // we should start with modern EHLO + if (250 != smtp_checkp("EHLO %s", opt_from, -1)) { smtp_checkp("HELO %s", opt_from, 250); } // set sender - // NOTE: if password has not been specified -> - // no authentication is possible + // NOTE: if password has not been specified + // then no authentication is possible code = (opts & OPT_P) ? -1 : 250; // first try softly without authentication while (250 != smtp_checkp("MAIL FROM:<%s>", opt_from, code)) { // MAIL FROM failed -> authentication needed - // do we have username? + // have we got username? if (!(opts & OPT_U)) { // no! fetch it from "from" option //opts |= OPT_U; opt_user = xstrdup(opt_from); *strchrnul(opt_user, '@') = '\0'; } - // now it seems we have username - // try to authenticate + // now we've got username + // so try to authenticate if (334 == smtp_check("AUTH LOGIN", -1)) { uuencode(NULL, opt_user); smtp_check("", 334); uuencode(NULL, opt_pass); smtp_check("", 235); } - // authenticated -> retry set sender - // but now die on failure + // authenticated OK? -> retry to set sender + // but this time die on failure! code = 250; } @@ -388,13 +384,15 @@ int sendgetmail_main(int argc, char **argv) smtp_checkp("RCPT TO:<%s>", sane(to->data), 250); } - // now put message + // enter "put message" mode smtp_check("DATA", 354); + // put address headers printf("From: %s\r\n", opt_from); for (llist_t *to = opt_recipients; to; to = to->link) { printf("To: %s\r\n", to->data); } + // put encoded subject if (opts & OPTS_c) sane((char *)opt_charset); @@ -403,17 +401,17 @@ int sendgetmail_main(int argc, char **argv) uuencode(NULL, opt_subject); printf("?=\r\n"); } + // put notification if (opts & OPTS_n) printf("Disposition-Notification-To: %s\r\n", opt_from); + + // make a random string -- it will delimit message parts + srand(monotonic_us()); + boundary = xasprintf("%d-%d-%d", rand(), rand(), rand()); + // put common headers and body start - // randomize -#if ENABLE_FEATURE_SENDMAIL_BLOATY - srand(time(NULL)); -#endif - boundary = xasprintf("%d-%d-%d", rand(), rand(), rand()); printf( - USE_FEATURE_SENDMAIL_BLOATY("X-Mailer: busybox " BB_VER " sendmail\r\n") "Message-ID: <%s>\r\n" "Mime-Version: 1.0\r\n" "%smultipart/mixed; boundary=\"%s\"\r\n" @@ -421,8 +419,10 @@ int sendgetmail_main(int argc, char **argv) , "Content-Type: " , boundary ); - // put body + attachment(s) + // put body + attachment(s) + // N.B. all these weird things just to be tiny + // by reusing string patterns! fmt = "\r\n--%s\r\n" "%stext/plain; charset=%s\r\n" @@ -453,44 +453,50 @@ int sendgetmail_main(int argc, char **argv) q = bb_get_last_path_component_strip(*argv); } - // put terminator + // put message terminator printf("\r\n--%s--\r\n" "\r\n", boundary); - if (ENABLE_FEATURE_CLEAN_UP) - free(boundary); - // end message and say goodbye - smtp_check(".", 250); + // leave "put message" mode + smtp_check(".", 250); + // ... and say goodbye smtp_check("QUIT", 221); #if ENABLE_FETCHMAIL } else { - // FETCHMAIL +/*************************************************** + * FETCHMAIL + ***************************************************/ + char *buf; unsigned nmsg; char *hostname; pid_t pid; - // cache fetch command + + // cache fetch command: + // TOP will return only the headers + // RETR will dump the whole message const char *retr = (opts & OPTF_t) ? "TOP %u 0" : "RETR %u"; // goto maildir xchdir(*argv++); -#if ENABLE_FEATURE_FETCHMAIL_FILTER // cache postprocess program *fargs = *argv; -#endif // authenticate if (!(opts & OPT_U)) { //opts |= OPT_U; - opt_user = getenv("USER"); + // N.B. IMHO getenv("USER") can be way easily spoofed! + opt_user = bb_getpwuid(NULL, -1, getuid()); } -#if ENABLE_FEATURE_FETCHMAIL_APOP + + // get server greeting pop3_checkr(NULL, NULL, &buf); + // server supports APOP? if ('<' == *buf) { md5_ctx_t md5; - // yes. compose <stamp><password> + // yes! compose <stamp><password> char *s = strchr(buf, '>'); if (s) strcpy(s+1, opt_pass); @@ -512,26 +518,22 @@ int sendgetmail_main(int argc, char **argv) free(s); free(buf-4); // buf is "+OK " away from malloc'ed string } + // server ignores APOP -> use simple text authentication } else { -#else - { - pop3_check(NULL, NULL); -#endif // USER pop3_check("USER %s", opt_user); // PASS pop3_check("PASS %s", opt_pass); } - // get statistics + // get mailbox statistics pop3_checkr("STAT", NULL, &buf); // prepare message filename suffix - hostname = xzalloc(MAXHOSTNAMELEN+1); - gethostname(hostname, MAXHOSTNAMELEN); + hostname = safe_gethostname(); pid = getpid(); - // get number of messages + // get messages counter // NOTE: we don't use xatou(buf) since buf is "nmsg nbytes" // we only need nmsg and atoi is just exactly what we need // if atoi fails to convert buf into number it returns 0 @@ -542,19 +544,19 @@ int sendgetmail_main(int argc, char **argv) // loop through messages for (; nmsg; nmsg--) { + + // generate unique filename char *filename = xasprintf("tmp/%llu.%u.%s", monotonic_us(), pid, hostname); char *target; -#if ENABLE_FEATURE_FETCHMAIL_FILTER - int rc; -#endif - // retrieve message in ./tmp + int rc; + + // retrieve message in ./tmp/ pop3_check(retr, (const char *)nmsg); pop3_message(filename); // delete message from server if (opts & OPTF_z) pop3_check("DELE %u", (const char*)nmsg); -#if ENABLE_FEATURE_FETCHMAIL_FILTER // run postprocessing program if (*fargs) { fargs[1] = filename; @@ -564,23 +566,18 @@ int sendgetmail_main(int argc, char **argv) if (1 == rc) goto skip; } -#endif - // atomically move message to ./new + + // atomically move message to ./new/ target = xstrdup(filename); strncpy(target, "new", 3); // ... or just stop receiving on error if (rename_or_warn(filename, target)) break; free(target); -#if ENABLE_FEATURE_FETCHMAIL_FILTER skip: -#endif free(filename); } - if (ENABLE_FEATURE_CLEAN_UP) - free(hostname); - // Bye pop3_check("QUIT", NULL); #endif // ENABLE_FETCHMAIL |