voicemail: Fix various abuses of mkstemp

mkstemp() returns a unique filename, but appending an extension to that
filename does not guarantee uniqueness. Instead, use mkdtemp() and we
can put whatever extension we want on the files that we create inside
the directory.

In the case of app_minivm, we also now properly clean up any temporary
files that we create.

ASTERISK-20858 #close
Reported by: Walter Doekes

Change-Id: I30ad04f0e115f0b11693ff678ba5184d8b938e43

2 files changed, 137 insertions, 78 deletions

diff --git a/apps/app_minivm.c b/apps/app_minivm.c
index 43cd7a29f..caf9f0107 100644
--- a/apps/app_minivm.c
+++ b/apps/app_minivm.c
@@ -1234,6 +1234,8 @@ static const char *ast_str_quote(struct ast_str **buf, ssize_t maxlen, const cha
  * \brief Send voicemail with audio file as an attachment */
 static int sendmail(struct minivm_template *template, struct minivm_account *vmu, char *cidnum, char *cidname, const char *filename, char *format, int duration, int attach_user_voicemail, enum mvm_messagetype type, const char *counter)
 {
+	RAII_VAR(struct ast_str *, str1, ast_str_create(16), ast_free);
+	RAII_VAR(struct ast_str *, str2, ast_str_create(16), ast_free);
 	FILE *p = NULL;
 	int pfd;
 	char email[256] = "";
@@ -1243,20 +1245,18 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 	char fname[PATH_MAX];
 	char dur[PATH_MAX];
 	char tmp[80] = "/tmp/astmail-XXXXXX";
-	char tmp2[PATH_MAX];
-	char newtmp[PATH_MAX]; /* Only used with volgain */
+	char mail_cmd_buffer[PATH_MAX];
+	char sox_gain_tmpdir[PATH_MAX] = ""; /* Only used with volgain */
+	char *file_to_delete = NULL, *dir_to_delete = NULL;
 	struct timeval now;
 	struct ast_tm tm;
 	struct minivm_zone *the_zone = NULL;
-	struct ast_channel *ast;
-	char *finalfilename = "";
-	struct ast_str *str1 = ast_str_create(16), *str2 = ast_str_create(16);
+	struct ast_channel *chan = NULL;
 	char *fromaddress;
 	char *fromemail;
+	int res;
 
 	if (!str1 || !str2) {
-		ast_free(str1);
-		ast_free(str2);
 		return -1;
 	}
 
@@ -1271,9 +1271,7 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 
 	if (ast_strlen_zero(email)) {
 		ast_log(LOG_WARNING, "No address to send message to.\n");
-		ast_free(str1);
-		ast_free(str2);
-		return -1;	
+		return -1;
 	}
 
 	ast_debug(3, "Sending mail to %s@%s - Using template %s\n", vmu->username, vmu->domain, template->name);
@@ -1281,35 +1279,30 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 	if (!strcmp(format, "wav49"))
 		format = "WAV";
 
-
 	/* If we have a gain option, process it now with sox */
 	if (type == MVM_MESSAGE_EMAIL && (vmu->volgain < -.001 || vmu->volgain > .001) ) {
-		char tmpcmd[PATH_MAX];
-		int tmpfd;
-
-		ast_copy_string(newtmp, "/tmp/XXXXXX", sizeof(newtmp));
-		ast_debug(3, "newtmp: %s\n", newtmp);
-		tmpfd = mkstemp(newtmp);
-		if (tmpfd < 0) {
-			ast_log(LOG_WARNING, "Failed to create temporary file for volgain: %d\n", errno);
-			ast_free(str1);
-			ast_free(str2);
+		char sox_gain_cmd[PATH_MAX];
+
+		ast_copy_string(sox_gain_tmpdir, "/tmp/minivm-gain-XXXXXX", sizeof(sox_gain_tmpdir));
+		ast_debug(3, "sox_gain_tmpdir: %s\n", sox_gain_tmpdir);
+		if (!mkdtemp(sox_gain_tmpdir)) {
+			ast_log(LOG_WARNING, "Failed to create temporary directory for volgain: %d\n", errno);
 			return -1;
 		}
-		snprintf(tmpcmd, sizeof(tmpcmd), "sox -v %.4f %s.%s %s.%s", vmu->volgain, filename, format, newtmp, format);
-		ast_safe_system(tmpcmd);
-		close(tmpfd);
-		finalfilename = newtmp;
+		snprintf(fname, sizeof(fname), "%s/output.%s", sox_gain_tmpdir, format);
+		snprintf(sox_gain_cmd, sizeof(sox_gain_cmd), "sox -v %.4f %s.%s %s", vmu->volgain, filename, format, fname);
+		ast_safe_system(sox_gain_cmd);
 		ast_debug(3, "VOLGAIN: Stored at: %s.%s - Level: %.4f - Mailbox: %s\n", filename, format, vmu->volgain, vmu->username);
+
+		/* Mark some things for deletion */
+		file_to_delete = fname;
+		dir_to_delete = sox_gain_tmpdir;
 	} else {
-		finalfilename = ast_strdupa(filename);
+		snprintf(fname, sizeof(fname), "%s.%s", filename, format);
 	}
 
-	/* Create file name */
-	snprintf(fname, sizeof(fname), "%s.%s", finalfilename, format);
-
 	if (template->attachment)
-		ast_debug(1, "Attaching file '%s', format '%s', uservm is '%d'\n", finalfilename, format, attach_user_voicemail);
+		ast_debug(1, "Attaching file '%s', format '%s', uservm is '%d'\n", fname, format, attach_user_voicemail);
 
 	/* Make a temporary file instead of piping directly to sendmail, in case the mail
 	   command hangs */
@@ -1324,16 +1317,12 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 	}
 	if (!p) {
 		ast_log(LOG_WARNING, "Unable to open temporary file '%s'\n", tmp);
-		ast_free(str1);
-		ast_free(str2);
-		return -1;
+		goto out;
 	}
 	/* Allocate channel used for chanvar substitution */
-	ast = ast_dummy_channel_alloc();
-	if (!ast) {
-		ast_free(str1);
-		ast_free(str2);
-		return -1;
+	chan = ast_dummy_channel_alloc();
+	if (!chan) {
+		goto out;
 	}
 
 	snprintf(dur, sizeof(dur), "%d:%02d", duration / 60, duration % 60);
@@ -1361,9 +1350,8 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 	/* Set date format for voicemail mail */
 	ast_strftime(date, sizeof(date), template->dateformat, &tm);
 
-
 	/* Populate channel with channel variables for substitution */
-	prep_email_sub_vars(ast, vmu, cidnum, cidname, dur, date, counter);
+	prep_email_sub_vars(chan, vmu, cidnum, cidname, dur, date, counter);
 
 	/* Find email address to use */
 	/* If there's a server e-mail address in the account, use that, othterwise template */
@@ -1388,7 +1376,7 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 		fprintf(p, "From: Asterisk PBX <%s>\n", who);
 	} else {
 		ast_debug(4, "Fromaddress template: %s\n", fromaddress);
-		ast_str_substitute_variables(&str1, 0, ast, fromaddress);
+		ast_str_substitute_variables(&str1, 0, chan, fromaddress);
 		if (check_mime(ast_str_buffer(str1))) {
 			int first_line = 1;
 			char *ptr;
@@ -1431,7 +1419,7 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 	}
 
 	if (!ast_strlen_zero(template->subject)) {
-		ast_str_substitute_variables(&str1, 0, ast, template->subject);
+		ast_str_substitute_variables(&str1, 0, chan, template->subject);
 		if (check_mime(ast_str_buffer(str1))) {
 			int first_line = 1;
 			char *ptr;
@@ -1464,7 +1452,7 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 	fprintf(p, "--%s\n", bound);
 	fprintf(p, "Content-Type: text/plain; charset=%s\nContent-Transfer-Encoding: 8bit\n\n", template->charset);
 	if (!ast_strlen_zero(template->body)) {
-		ast_str_substitute_variables(&str1, 0, ast, template->body);
+		ast_str_substitute_variables(&str1, 0, chan, template->body);
 		ast_debug(3, "Message now: %s\n-----\n", ast_str_buffer(str1));
 		fprintf(p, "%s\n", ast_str_buffer(str1));
 	} else {
@@ -1491,14 +1479,45 @@ static int sendmail(struct minivm_template *template, struct minivm_account *vmu
 		fprintf(p, "\n\n--%s--\n.\n", bound);
 	}
 	fclose(p);
-	snprintf(tmp2, sizeof(tmp2), "( %s < %s ; rm -f %s ) &", global_mailcmd, tmp, tmp);
-	ast_safe_system(tmp2);
-	ast_debug(1, "Sent message to %s with command '%s' - %s\n", vmu->email, global_mailcmd, template->attachment ? "(media attachment)" : "");
-	ast_debug(3, "Actual command used: %s\n", tmp2);
-	ast = ast_channel_unref(ast);
-	ast_free(str1);
-	ast_free(str2);
-	return 0;
+
+	chan = ast_channel_unref(chan);
+
+	if (file_to_delete && dir_to_delete) {
+		/* We can't delete these files ourselves because the mail command will execute in
+		   the background and we'll end up deleting them out from under it. */
+		res = snprintf(mail_cmd_buffer, sizeof(mail_cmd_buffer),
+					   "( %s < %s ; rm -f %s %s ; rmdir %s ) &",
+					   global_mailcmd, tmp, tmp, file_to_delete, dir_to_delete);
+	} else {
+		res = snprintf(mail_cmd_buffer, sizeof(mail_cmd_buffer),
+					   "( %s < %s ; rm -f %s ) &",
+					   global_mailcmd, tmp, tmp);
+	}
+
+	if (res < sizeof(mail_cmd_buffer)) {
+		file_to_delete = dir_to_delete = NULL;
+	} else {
+		ast_log(LOG_ERROR, "Could not send message, command line too long\n");
+		res = -1;
+		goto out;
+	}
+
+	ast_safe_system(mail_cmd_buffer);
+	ast_debug(1, "Sent message to %s with command '%s'%s\n", vmu->email, global_mailcmd, template->attachment ? " - (media attachment)" : "");
+	ast_debug(3, "Actual command used: %s\n", mail_cmd_buffer);
+
+	res = 0;
+
+out:
+	if (file_to_delete) {
+		unlink(file_to_delete);
+	}
+
+	if (dir_to_delete) {
+		rmdir(dir_to_delete);
+	}
+
+	return res;
 }
 
 /*!\internal
diff --git a/apps/app_voicemail.c b/apps/app_voicemail.c
index 58b4e64a4..f954e278e 100644
--- a/apps/app_voicemail.c
+++ b/apps/app_voicemail.c
@@ -5372,55 +5372,95 @@ plain_message:
 
 static int add_email_attachment(FILE *p, struct ast_vm_user *vmu, char *format, char *attach, char *greeting_attachment, char *mailbox, char *bound, char *filename, int last, int msgnum)
 {
-	char tmpdir[256], newtmp[256];
-	char fname[256];
-	char tmpcmd[256];
-	int tmpfd = -1;
-	int soxstatus = 0;
+	char fname[PATH_MAX] = "";
+	char *file_to_delete = NULL, *dir_to_delete = NULL;
+	int res;
 
 	/* Eww. We want formats to tell us their own MIME type */
-	char *ctype = (!strcasecmp(format, "ogg")) ? "application/" : "audio/x-";
+	char *mime_type = (!strcasecmp(format, "ogg")) ? "application/" : "audio/x-";
+
+	/* This 'while' loop will only execute once. We use it so that we can 'break' */
+	while (vmu->volgain < -.001 || vmu->volgain > .001) {
+		char tmpdir[PATH_MAX];
+		char sox_gain_tmpdir[PATH_MAX];
 
-	if (vmu->volgain < -.001 || vmu->volgain > .001) {
 		create_dirpath(tmpdir, sizeof(tmpdir), vmu->context, vmu->mailbox, "tmp");
-		snprintf(newtmp, sizeof(newtmp), "%s/XXXXXX", tmpdir);
-		tmpfd = mkstemp(newtmp);
-		chmod(newtmp, VOICEMAIL_FILE_MODE & ~my_umask);
-		ast_debug(3, "newtmp: %s\n", newtmp);
-		if (tmpfd > -1) {
-			snprintf(tmpcmd, sizeof(tmpcmd), "sox -v %.4f %s.%s %s.%s", vmu->volgain, attach, format, newtmp, format);
-			if ((soxstatus = ast_safe_system(tmpcmd)) == 0) {
-				attach = newtmp;
-				ast_debug(3, "VOLGAIN: Stored at: %s.%s - Level: %.4f - Mailbox: %s\n", attach, format, vmu->volgain, mailbox);
+
+		res = snprintf(sox_gain_tmpdir, sizeof(sox_gain_tmpdir), "%s/vm-gain-XXXXXX", tmpdir);
+		if (res >= sizeof(sox_gain_tmpdir)) {
+			ast_log(LOG_ERROR, "Failed to create temporary directory path %s: Out of buffer space\n", tmpdir);
+			break;
+		}
+
+		if (mkdtemp(sox_gain_tmpdir)) {
+			int soxstatus = 0;
+			char sox_gain_cmd[PATH_MAX];
+
+			ast_debug(3, "sox_gain_tmpdir: %s\n", sox_gain_tmpdir);
+
+			/* Save for later */
+			dir_to_delete = sox_gain_tmpdir;
+
+			res = snprintf(fname, sizeof(fname), "%s/output.%s", sox_gain_tmpdir, format);
+			if (res >= sizeof(fname)) {
+				ast_log(LOG_ERROR, "Failed to create filename buffer for %s/output.%s: Too long\n", sox_gain_tmpdir, format);
+				break;
+			}
+
+			res = snprintf(sox_gain_cmd, sizeof(sox_gain_cmd), "sox -v %.4f %s.%s %s",
+						   vmu->volgain, attach, format, fname);
+			if (res >= sizeof(sox_gain_cmd)) {
+				ast_log(LOG_ERROR, "Failed to generate sox command, out of buffer space\n");
+				break;
+			}
+
+			soxstatus = ast_safe_system(sox_gain_cmd);
+			if (!soxstatus) {
+				/* Save for later */
+				file_to_delete = fname;
+				ast_debug(3, "VOLGAIN: Stored at: %s - Level: %.4f - Mailbox: %s\n", fname, vmu->volgain, mailbox);
 			} else {
-				ast_log(LOG_WARNING, "Sox failed to re-encode %s.%s: %s (have you installed support for all sox file formats?)\n", attach, format,
-					soxstatus == 1 ? "Problem with command line options" : "An error occurred during file processing");
+				ast_log(LOG_WARNING, "Sox failed to re-encode %s: %s (have you installed support for all sox file formats?)\n",
+						fname,
+						soxstatus == 1 ? "Problem with command line options" : "An error occurred during file processing");
 				ast_log(LOG_WARNING, "Voicemail attachment will have no volume gain.\n");
 			}
 		}
+
+		break;
+	}
+
+	if (!file_to_delete) {
+		res = snprintf(fname, sizeof(fname), "%s.%s", attach, format);
+		if (res >= sizeof(fname)) {
+			ast_log(LOG_ERROR, "Failed to create filename buffer for %s.%s: Too long\n", attach, format);
+			return -1;
+		}
 	}
+
 	fprintf(p, "--%s" ENDL, bound);
 	if (msgnum > -1)
-		fprintf(p, "Content-Type: %s%s; name=\"%s\"" ENDL, ctype, format, filename);
+		fprintf(p, "Content-Type: %s%s; name=\"%s\"" ENDL, mime_type, format, filename);
 	else
-		fprintf(p, "Content-Type: %s%s; name=\"%s.%s\"" ENDL, ctype, format, greeting_attachment, format);
+		fprintf(p, "Content-Type: %s%s; name=\"%s.%s\"" ENDL, mime_type, format, greeting_attachment, format);
 	fprintf(p, "Content-Transfer-Encoding: base64" ENDL);
 	fprintf(p, "Content-Description: Voicemail sound attachment." ENDL);
 	if (msgnum > -1)
 		fprintf(p, "Content-Disposition: attachment; filename=\"%s\"" ENDL ENDL, filename);
 	else
 		fprintf(p, "Content-Disposition: attachment; filename=\"%s.%s\"" ENDL ENDL, greeting_attachment, format);
-	snprintf(fname, sizeof(fname), "%s.%s", attach, format);
 	base_encode(fname, p);
 	if (last)
 		fprintf(p, ENDL ENDL "--%s--" ENDL "." ENDL, bound);
-	if (tmpfd > -1) {
-		if (soxstatus == 0) {
-			unlink(fname);
-		}
-		close(tmpfd);
-		unlink(newtmp);
+
+	if (file_to_delete) {
+		unlink(file_to_delete);
 	}
+
+	if (dir_to_delete) {
+		rmdir(dir_to_delete);
+	}
+
 	return 0;
 }