sendmail: yet another maintainer's update
authorDenis Vlasenko <vda.linux@googlemail.com>
Wed, 27 Feb 2008 09:39:04 +0000 (09:39 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Wed, 27 Feb 2008 09:39:04 +0000 (09:39 -0000)
include/usage.h
networking/Config.in
networking/sendmail.c

index e9770cea9392daa848e76280af9a36b2760cffe9..95cb69c7356d918f96dde97005470b41ea0b2a03 100644 (file)
@@ -1035,10 +1035,8 @@ USE_FEATURE_BRCTL_FANCY("\n" \
        "       -P password     Authenticate with specified password\n" \
        "       -X              Use openssl connection helper for secured servers\n" \
        "       -t              Get only headers\n" \
-       "       -z              Delete messages on server" \
-USE_FEATURE_FETCHMAIL_FILTER("\n" \
-       "        prog           Run prog <message file> on message delivery" \
-)
+       "       -z              Delete messages on server\n" \
+       "        prog           Run prog <message file> on message delivery"
 
 #define findfs_trivial_usage \
        "LABEL=label or UUID=uuid"
index 202b65fcea7ecd5b9debee089acfd3a736a8a90a..3c53c11157b749fe3984a0f0fcbc9cae5e8647dd 100644 (file)
@@ -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"
index adc6c76264ad3baac05cc0e59ca4b3ac5af3ce4a..3a6078f796d44eea5bf121fb879a42ee3af4682a 100644 (file)
@@ -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