sendmail: fixes by Vladimir Dronnikov <dronnikov at gmail.com>

2 files changed, 111 insertions, 85 deletions

diff --git a/include/usage.h b/include/usage.h
index 0ef17b520..989ed9134 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -3135,26 +3135,28 @@ USE_FEATURE_RUN_PARTS_FANCY("\n	-l	Prints names of all matching files even when
 #define selinuxenabled_full_usage
 
 #define sendmail_trivial_usage \
-       "[-d] {-t to}+ [-f from] [-n[notify]] [-s subject] [-b file]*\n" \
-       "[-a attachment]* [-c charset] [-w timeout] [-h server] [-p port] [-U user] [-P password]"
+       "{-t to}+ {-f from} [-n[notify]] [-s subject] [-b file]*\n" \
+       "[-a attachment]* [-c charset]" \
+       USE_FEATURE_SENDMAIL_NETWORK("\n" \
+       " [-d] [-w timeout] [-h server] [-p port] [-U user] [-P password]" \
+       )
 #define sendmail_full_usage \
-       "Send an email from to with subject and optional attachments.\n" \
-       "Body is read from stdin or from optional files" \
+       "Send an email <from> <to> with <subject> and optional attachments." \
        "\n\nArguments:\n" \
-       "        -d              Just dump composed message\n" \
        "        -t to           Recipient email. May be multiple\n" \
-       "        -f from         Sender email\n" \
+       "        -f from         Sender address\n" \
        "        -n[notify]      Optional notification address. If just -n given then notifies the sender\n" \
        "        -s subject      Optional subject\n" \
        "        -b filename     Optional body content file. May be multiple\n" \
        "        -a filename     Optional file attachment. May be multiple\n" \
        "        -c charset      Assumed charset for body and subject [koi8-r]" \
        USE_FEATURE_SENDMAIL_NETWORK("\n" \
+       "        -d              Just dump composed message\n" \
        "        -w timeout      Set timeout on network operations\n" \
        "        -h server       Optional mail server name or IP [127.0.0.1]\n" \
        "        -p port         Optional mail server port [25]\n" \
        "        -U username     Authenticate using AUTH LOGIN with specified username\n" \
-       "        -P password     Authenticate using AUTH LOGIN with specified password"\
+       "        -P password     Authenticate using AUTH LOGIN with specified password" \
        )
 
 #define seq_trivial_usage \
diff --git a/networking/sendmail.c b/networking/sendmail.c
index 2ea10b124..fa1abc7ff 100644
--- a/networking/sendmail.c
+++ b/networking/sendmail.c
@@ -16,45 +16,46 @@ enum {
         DST_BUF_SIZE = 4 * ((SRC_BUF_SIZE + 2) / 3),
 };
 
-static void uuencode(const char *fname)
+static void uuencode(char *fname, const char *text)
 {
+#define src_buf text
         int fd;
-        char src_buf[SRC_BUF_SIZE];
-        char dst_buf[1 + DST_BUF_SIZE + 1];
+#define len fd
+        char dst_buf[DST_BUF_SIZE + 1];
 
-        fd = xopen(fname, O_RDONLY);
-        fflush(stdout);
-        dst_buf[0] = '\n';
+        if (fname) {
+                fd = xopen(fname, O_RDONLY);
+                src_buf = bb_common_bufsiz1;
+        } else {
+                len = strlen(text);
+        }
+
+        fflush(stdout); // sync stdio and unistd output
         while (1) {
-                size_t size = full_read(fd, src_buf, SRC_BUF_SIZE);
+                size_t size;
+                if (fname) {
+                        size = full_read(fd, (char *)src_buf, SRC_BUF_SIZE);
+                        if ((ssize_t)size < 0)
+                                bb_perror_msg_and_die(bb_msg_read_error);
+                } else {
+                        size = len;
+                        if (len > SRC_BUF_SIZE)
+                                size = SRC_BUF_SIZE;
+                }
                 if (!size)
                         break;
-                if ((ssize_t)size < 0)
-                        bb_perror_msg_and_die(bb_msg_read_error);
-                /* Encode the buffer we just read in */
-                bb_uuencode(dst_buf + 1, src_buf, size, bb_uuenc_tbl_base64);
-                xwrite(STDOUT_FILENO, dst_buf, 1 + 4 * ((size + 2) / 3));
-        }
-        close(fd);
-}
-
-// "inline" version
-// encodes content of given buffer instead of fd
-// used to encode subject and authentication terms
-static void uuencode_inline(const char *src_buf)
-{
-        size_t len;
-        char dst_buf[DST_BUF_SIZE + 1];
-
-        len = strlen(src_buf);
-        fflush(stdout);
-        while (len > 0) {
-                size_t chunk = (len <= SRC_BUF_SIZE) ? len : SRC_BUF_SIZE;
-                bb_uuencode(dst_buf, src_buf, chunk, bb_uuenc_tbl_base64);
-                xwrite(STDOUT_FILENO, dst_buf, 4 * ((chunk + 2) / 3));
-                src_buf += chunk;
-                len -= chunk;
+                // Encode the buffer we just read in
+                bb_uuencode(dst_buf, src_buf, size, bb_uuenc_tbl_base64);
+                if (fname) {
+                        xwrite(STDOUT_FILENO, "\n", 1);
+                } else {
+                        src_buf += size;
+                        len -= size;
+                }
+                xwrite(STDOUT_FILENO, dst_buf, 4 * ((size + 2) / 3));
         }
+        if (ENABLE_FEATURE_CLEAN_UP && fname)
+                close(fd);
 }
 
 #if ENABLE_FEATURE_SENDMAIL_NETWORK
@@ -72,7 +73,7 @@ static void signal_handler(int signo)
                         bb_error_msg_and_die("child exited (%d)", WEXITSTATUS(err));
 }
 
-static pid_t helper_pid = -1;
+static pid_t helper_pid;
 
 // read stdin, parses first bytes to a number, i.e. server response
 // if code = -1 then just return this number
@@ -92,7 +93,7 @@ static int check(int code, const char *errmsg)
                         return n;
                 }
         }
-        // TODO!!!: is there more elegant way to terminate child on program failure?
+        // TODO: is there more elegant way to terminate child on program failure?
         if (helper_pid > 0)
                 kill(helper_pid, SIGTERM);
         if (!answer)
@@ -104,9 +105,24 @@ static int check(int code, const char *errmsg)
 
 static int puts_and_check(const char *msg, int code, const char *errmsg)
 {
-        puts(msg);
+        printf("%s\r\n", msg);
         return check(code, errmsg);
 }
+
+// strip argument of bad chars
+static char *sane(char *str)
+{
+        char *s = str;
+        char *p = s;
+        while (*s) {
+                if (isalnum(*s) || '_' == *s || '-' == *s || '.' == *s || '@' == *s) {
+                        *p++ = *s;
+                }
+                s++;
+        }
+        *p = '\0';
+        return str;
+}
 #endif
 
 int sendmail_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
@@ -115,10 +131,10 @@ int sendmail_main(int argc, char **argv)
         llist_t *recipients = NULL;
         llist_t *bodies = NULL;
         llist_t *attachments = NULL;
-        const char *from;
-        const char *notify;
+        char *from;
+        char *notify = NULL;
         const char *subject;
-        const char *charset = "utf-8";
+        char *charset = (char*)"utf-8";
 #if ENABLE_FEATURE_SENDMAIL_NETWORK
         const char *wsecs = "10";
         const char *server = "127.0.0.1";
@@ -133,6 +149,7 @@ int sendmail_main(int argc, char **argv)
                 OPT_f = 1 << 0,         // sender
                 OPT_n = 1 << 2,         // notification
                 OPT_s = 1 << 3,         // subject given
+                OPT_c = 1 << 6,         // charset
                 OPT_d = 1 << 7,         // dry run - no networking
                 OPT_w = 1 << 8,         // network timeout
                 OPT_h = 1 << 9,         // server
@@ -152,9 +169,10 @@ int sendmail_main(int argc, char **argv)
         //argc -= optind;
         argv += optind;
 
-//printf("OPTS[%4x]\n", opts);
-
-        // TODO!!!: strip recipients and sender from <>
+        // sanitize user input
+        sane(from);
+        if (opts & OPT_c)
+                sane(charset);
 
         // establish connection
 #if ENABLE_FEATURE_SENDMAIL_NETWORK
@@ -167,24 +185,24 @@ int sendmail_main(int argc, char **argv)
                                 bb_error_msg_and_die("no password");
                         }
                 }
-//printf("OPTS[%4x][%s][%s]\n", opts, opt_user, opt_pass);
-//exit(0);
                 // set chat timeout
                 alarm(timeout);
                 // connect to server
                 if (argv[0]) {
                         // if connection helper given
                         // setup vanilla unidirectional pipes interchange
+                        int idx;
                         int pipes[4];
                         xpipe(pipes);
                         xpipe(pipes+2);
                         helper_pid = vfork();
                         if (helper_pid < 0)
                                 bb_perror_msg_and_die("vfork");
-                        xdup2(pipes[(helper_pid)?0:2], STDIN_FILENO);
-                        xdup2(pipes[(helper_pid)?3:1], STDOUT_FILENO);
+                        idx = (!helper_pid)*2;
+                        xdup2(pipes[idx], STDIN_FILENO);
+                        xdup2(pipes[3-idx], STDOUT_FILENO);
                         if (ENABLE_FEATURE_CLEAN_UP)
-                                for (int i = 4; --i >= 0; )
+                                for (int i = 4; --i >= 0;)
                                         if (pipes[i] > STDOUT_FILENO)
                                                 close(pipes[i]);
                         // replace child with connection helper
@@ -210,10 +228,12 @@ int sendmail_main(int argc, char **argv)
                         check(220, "INIT");
                 }
                 // mail user specified? try modern AUTHentication
-                if (opt_user && (334 == puts_and_check("auth login", -1, "auth login"))) {
-                        uuencode_inline(opt_user);
+                if ((opts & OPT_U)
+                 && (334 == puts_and_check("auth login", -1, "auth login"))
+                ) {
+                        uuencode(NULL, opt_user);
                         puts_and_check("", 334, "AUTH");
-                        uuencode_inline(opt_pass);
+                        uuencode(NULL, opt_pass);
                         puts_and_check("", 235, "AUTH");
                 // no mail user specified or modern AUTHentication is not supported?
                 } else {
@@ -224,15 +244,15 @@ int sendmail_main(int argc, char **argv)
                                 domain++;
                         else
                                 domain = "local";
-                        printf("helo %s\n", domain);
+                        printf("helo %s\r\n", domain);
                         check(250, "HELO");
                 }
 
                 // set addresses
-                printf("mail from:<%s>\n", from);
+                printf("mail from:<%s>\r\n", from);
                 check(250, "MAIL FROM");
                 for (llist_t *to = recipients; to; to = to->link) {
-                        printf("rcpt to:<%s>\n", to->data);
+                        printf("rcpt to:<%s>\r\n", sane(to->data));
                         check(250, "RCPT TO");
                 }
                 puts_and_check("data", 354, "DATA");
@@ -243,60 +263,64 @@ int sendmail_main(int argc, char **argv)
 
         // now put message
         // put address headers
-        printf("From: %s\n", from);
+        printf("From: %s\r\n", from);
         for (llist_t *to = recipients; to; to = to->link) {
-                printf("To: %s\n", to->data);
+                printf("To: %s\r\n", sane(to->data));
         }
         // put encoded subject
         if (opts & OPT_s) {
                 printf("Subject: =?%s?B?", charset);
-                uuencode_inline(subject);
-                puts("?=");
+                uuencode(NULL, subject);
+                puts("?=\r");
         }
         // put notification
         if (opts & OPT_n) {
-                const char *s = notify;
-                if (!s[0])
-                        s = from; // notify sender by default
-                printf("Disposition-Notification-To: %s\n", s);
+                // -n without parameter?
+                if (!notify)
+                        notify = from; // notify sender by default
+                printf("Disposition-Notification-To: %s\r\n", sane(notify));
         }
         // put common headers and body start
         //srand(?);
         boundary = xasprintf("%d-%d-%d", rand(), rand(), rand());
         printf(
-                "X-Mailer: busybox " BB_VER " sendmail\n"
-                "X-Priority: 3\n"
-                "Message-ID: <%s>\n"
-                "Mime-Version: 1.0\n"
-                "Content-Type: multipart/mixed; boundary=\"%s\"\n"
-                "\n"
-                "--%s\n"
-                "Content-Type: text/plain; charset=%s\n"
-                "%s\n%s"
-                , boundary, boundary, boundary, charset
+                "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"
+                "\r\n"
+                "--%s\r\n"
+                "%stext/plain; charset=%s\r\n"
+                "%s\r\n%s"
+                , boundary
+                , "Content-Type: "
+                , boundary, boundary
+                , "Content-Type: "
+                , charset
                 , "Content-Disposition: inline"
-                , "Content-Transfer-Encoding: base64\n"
+                , "Content-Transfer-Encoding: base64\r\n"
         );
         // put body(ies)
         for (llist_t *f = bodies; f; f = f->link) {
-                uuencode(f->data);
+                uuencode(f->data, NULL);
         }
         // put attachment(s)
         for (llist_t *f = attachments; f; f = f->link) {
                 printf(
-                        "\n--%s\n"
-                        "Content-Type: application/octet-stream\n"
-                        "%s; filename=\"%s\"\n"
+                        "\r\n--%s\r\n"
+                        "%sapplication/octet-stream\r\n"
+                        "%s; filename=\"%s\"\r\n"
                         "%s"
                         , boundary
+                        , "Content-Type: "
                         , "Content-Disposition: inline"
                         , bb_get_last_path_component_strip(f->data)
-                        , "Content-Transfer-Encoding: base64\n"
+                        , "Content-Transfer-Encoding: base64\r\n"
                 );
-                uuencode(f->data);
+                uuencode(f->data, NULL);
         }
         // put terminator
-        printf("\n--%s--\n\n", boundary);
+        printf("\r\n--%s--\r\n\r\n", boundary);
         if (ENABLE_FEATURE_CLEAN_UP)
                 free(boundary);