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-rw-r--r--src/dcc.c512
1 files changed, 512 insertions, 0 deletions
diff --git a/src/dcc.c b/src/dcc.c
new file mode 100644
index 0000000..5aa2b17
--- /dev/null
+++ b/src/dcc.c
@@ -0,0 +1,512 @@
+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/* Copyright (c) Wolfgang Breyha 2005 - 2015
+ * Vienna University Computer Center
+ * wbreyha@gmx.net
+ * See the file NOTICE for conditions of use and distribution.
+ *
+ * Copyright (c) The Exim Maintainers 2015 - 2018
+ */
+
+/* This patch is based on code from Tom Kistners exiscan (ACL integration) and
+ * the DCC local_scan patch from Christopher Bodenstein */
+
+/* Code for calling dccifd. Called from acl.c. */
+
+#include "exim.h"
+#ifdef EXPERIMENTAL_DCC
+#include "dcc.h"
+#include "unistd.h"
+
+uschar dcc_header_str[256];
+int dcc_ok = 0;
+int dcc_rc = 0;
+
+/* This function takes a file descriptor and a buffer as input and
+ * returns either 0 for success or errno in case of error. */
+
+int flushbuffer (int socket, uschar *buffer)
+ {
+ int retval, rsp;
+ rsp = write(socket, buffer, Ustrlen(buffer));
+ DEBUG(D_acl)
+ debug_printf("DCC: Result of the write() = %d\n", rsp);
+ if(rsp < 0)
+ {
+ DEBUG(D_acl)
+ debug_printf("DCC: Error writing buffer to socket: %s\n", strerror(errno));
+ retval = errno;
+ }
+ else {
+ DEBUG(D_acl)
+ debug_printf("DCC: Wrote buffer to socket:\n%s\n", buffer);
+ retval = 0;
+ }
+ return retval;
+}
+
+int
+dcc_process(uschar **listptr)
+{
+ int sep = 0;
+ const uschar *list = *listptr;
+ FILE *data_file;
+ uschar *dcc_default_ip_option = US"127.0.0.1";
+ uschar *dcc_helo_option = US"localhost";
+ uschar *dcc_reject_message = US"Rejected by DCC";
+ uschar *xtra_hdrs = NULL;
+ uschar *override_client_ip = NULL;
+
+ /* from local_scan */
+ int i, j, k, c, retval, sockfd, resp, line;
+ unsigned int portnr;
+ struct sockaddr_un serv_addr;
+ struct sockaddr_in serv_addr_in;
+ struct hostent *ipaddress;
+ uschar sockpath[128];
+ uschar sockip[40], client_ip[40];
+ uschar opts[128];
+ uschar rcpt[128], from[128];
+ uschar sendbuf[4096];
+ uschar recvbuf[4096];
+ uschar dcc_return_text[1024];
+ uschar message_subdir[2];
+ struct header_line *dcchdr;
+ uschar *dcc_acl_options;
+ uschar dcc_acl_options_buffer[10];
+ uschar dcc_xtra_hdrs[1024];
+
+ /* grep 1st option */
+ if ((dcc_acl_options = string_nextinlist(&list, &sep,
+ dcc_acl_options_buffer, sizeof(dcc_acl_options_buffer))))
+ {
+ /* parse 1st option */
+ if ( strcmpic(dcc_acl_options, US"false") == 0
+ || Ustrcmp(dcc_acl_options, "0") == 0
+ )
+ return FAIL; /* explicitly no matching */
+ }
+ else
+ return FAIL; /* empty means "don't match anything" */
+
+ sep = 0;
+
+ /* if we scanned this message last time, just return */
+ if (dcc_ok)
+ return dcc_rc;
+
+ /* open the spooled body */
+ message_subdir[1] = '\0';
+ for (i = 0; i < 2; i++)
+ {
+ message_subdir[0] = split_spool_directory == (i == 0) ? message_id[5] : 0;
+
+ if ((data_file = Ufopen(
+ spool_fname(US"input", message_subdir, message_id, US"-D"),
+ "rb")))
+ break;
+ }
+
+ if (!data_file)
+ {
+ /* error while spooling */
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "dcc acl condition: error while opening spool file");
+ return DEFER;
+ }
+
+ /* Initialize the variables */
+
+ bzero(sockip,sizeof(sockip));
+ if (dccifd_address) {
+ if (dccifd_address[0] == '/')
+ Ustrncpy(sockpath, dccifd_address, sizeof(sockpath));
+ else
+ if( sscanf(CS dccifd_address, "%s %u", sockip, &portnr) != 2) {
+ log_write(0, LOG_MAIN,
+ "dcc acl condition: warning - invalid dccifd address: '%s'", dccifd_address);
+ (void)fclose(data_file);
+ return DEFER;
+ }
+ }
+
+ /* opts is what we send as dccifd options - see man dccifd */
+ /* We don't support any other option than 'header' so just copy that */
+ bzero(opts,sizeof(opts));
+ Ustrncpy(opts, dccifd_options, sizeof(opts)-1);
+ /* if $acl_m_dcc_override_client_ip is set use it */
+ if (((override_client_ip = expand_string(US"$acl_m_dcc_override_client_ip")) != NULL) &&
+ (override_client_ip[0] != '\0')) {
+ Ustrncpy(client_ip, override_client_ip, sizeof(client_ip)-1);
+ DEBUG(D_acl)
+ debug_printf("DCC: Client IP (overridden): %s\n", client_ip);
+ }
+ else if(sender_host_address) {
+ /* else if $sender_host_address is available use that? */
+ Ustrncpy(client_ip, sender_host_address, sizeof(client_ip)-1);
+ DEBUG(D_acl)
+ debug_printf("DCC: Client IP (sender_host_address): %s\n", client_ip);
+ }
+ else {
+ /* sender_host_address is NULL which means it comes from localhost */
+ Ustrncpy(client_ip, dcc_default_ip_option, sizeof(client_ip)-1);
+ DEBUG(D_acl)
+ debug_printf("DCC: Client IP (default): %s\n", client_ip);
+ }
+ /* strncat(opts, my_request, strlen(my_request)); */
+ Ustrcat(opts, "\n");
+ Ustrncat(opts, client_ip, sizeof(opts)-Ustrlen(opts)-1);
+ Ustrncat(opts, "\nHELO ", sizeof(opts)-Ustrlen(opts)-1);
+ Ustrncat(opts, dcc_helo_option, sizeof(opts)-Ustrlen(opts)-2);
+ Ustrcat(opts, "\n");
+
+ /* initialize the other variables */
+ dcchdr = header_list;
+ /* we set the default return value to DEFER */
+ retval = DEFER;
+
+ bzero(sendbuf,sizeof(sendbuf));
+ bzero(dcc_header_str,sizeof(dcc_header_str));
+ bzero(rcpt,sizeof(rcpt));
+ bzero(from,sizeof(from));
+
+ /* send a null return path as "<>". */
+ if (Ustrlen(sender_address) > 0)
+ Ustrncpy(from, sender_address, sizeof(from));
+ else
+ Ustrncpy(from, "<>", sizeof(from));
+ Ustrncat(from, "\n", sizeof(from)-Ustrlen(from)-1);
+
+ /**************************************
+ * Now creating the socket connection *
+ **************************************/
+
+ /* If sockip contains an ip, we use a tcp socket, otherwise a UNIX socket */
+ if(Ustrcmp(sockip, "")){
+ ipaddress = gethostbyname(CS sockip);
+ bzero(CS &serv_addr_in, sizeof(serv_addr_in));
+ serv_addr_in.sin_family = AF_INET;
+ bcopy(CS ipaddress->h_addr, CS &serv_addr_in.sin_addr.s_addr, ipaddress->h_length);
+ serv_addr_in.sin_port = htons(portnr);
+ if ((sockfd = socket(AF_INET, SOCK_STREAM,0)) < 0){
+ DEBUG(D_acl)
+ debug_printf("DCC: Creating TCP socket connection failed: %s\n", strerror(errno));
+ log_write(0,LOG_PANIC,"DCC: Creating TCP socket connection failed: %s\n", strerror(errno));
+ /* if we cannot create the socket, defer the mail */
+ (void)fclose(data_file);
+ return retval;
+ }
+ /* Now connecting the socket (INET) */
+ if (connect(sockfd, (struct sockaddr *)&serv_addr_in, sizeof(serv_addr_in)) < 0){
+ DEBUG(D_acl)
+ debug_printf("DCC: Connecting to TCP socket failed: %s\n", strerror(errno));
+ log_write(0,LOG_PANIC,"DCC: Connecting to TCP socket failed: %s\n", strerror(errno));
+ /* if we cannot contact the socket, defer the mail */
+ (void)fclose(data_file);
+ return retval;
+ }
+ } else {
+ /* connecting to the dccifd UNIX socket */
+ bzero(&serv_addr, sizeof(serv_addr));
+ serv_addr.sun_family = AF_UNIX;
+ Ustrncpy(serv_addr.sun_path, sockpath, sizeof(serv_addr.sun_path));
+ if ((sockfd = socket(AF_UNIX, SOCK_STREAM,0)) < 0){
+ DEBUG(D_acl)
+ debug_printf("DCC: Creating UNIX socket connection failed: %s\n", strerror(errno));
+ log_write(0,LOG_PANIC,"DCC: Creating UNIX socket connection failed: %s\n", strerror(errno));
+ /* if we cannot create the socket, defer the mail */
+ (void)fclose(data_file);
+ return retval;
+ }
+ /* Now connecting the socket (UNIX) */
+ if (connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0){
+ DEBUG(D_acl)
+ debug_printf("DCC: Connecting to UNIX socket failed: %s\n", strerror(errno));
+ log_write(0,LOG_PANIC,"DCC: Connecting to UNIX socket failed: %s\n", strerror(errno));
+ /* if we cannot contact the socket, defer the mail */
+ (void)fclose(data_file);
+ return retval;
+ }
+ }
+ /* the socket is open, now send the options to dccifd*/
+ DEBUG(D_acl)
+ debug_printf("\nDCC: ---------------------------\nDCC: Socket opened; now sending input\nDCC: -----------------\n");
+ /* First, fill in the input buffer */
+ Ustrncpy(sendbuf, opts, sizeof(sendbuf));
+ Ustrncat(sendbuf, from, sizeof(sendbuf)-Ustrlen(sendbuf)-1);
+
+ DEBUG(D_acl)
+ {
+ debug_printf("DCC: opts = %s\nDCC: sender = %s\nDCC: rcpt count = %d\n", opts, from, recipients_count);
+ debug_printf("DCC: Sending options:\nDCC: ****************************\n");
+ }
+
+ /* let's send each of the recipients to dccifd */
+ for (i = 0; i < recipients_count; i++){
+ DEBUG(D_acl)
+ debug_printf("DCC: recipient = %s\n",recipients_list[i].address);
+ if(Ustrlen(sendbuf) + Ustrlen(recipients_list[i].address) > sizeof(sendbuf))
+ {
+ DEBUG(D_acl)
+ debug_printf("DCC: Writing buffer: %s\n", sendbuf);
+ flushbuffer(sockfd, sendbuf);
+ bzero(sendbuf, sizeof(sendbuf));
+ }
+ Ustrncat(sendbuf, recipients_list[i].address, sizeof(sendbuf)-Ustrlen(sendbuf)-1);
+ Ustrncat(sendbuf, "\r\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
+ }
+ /* send a blank line between options and message */
+ Ustrncat(sendbuf, "\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
+ /* Now we send the input buffer */
+ DEBUG(D_acl)
+ debug_printf("DCC: %s\nDCC: ****************************\n", sendbuf);
+ flushbuffer(sockfd, sendbuf);
+
+ /* now send the message */
+ /* Clear the input buffer */
+ bzero(sendbuf, sizeof(sendbuf));
+ /* First send the headers */
+ /* Now send the headers */
+ DEBUG(D_acl)
+ debug_printf("DCC: Sending headers:\nDCC: ****************************\n");
+ Ustrncpy(sendbuf, dcchdr->text, sizeof(sendbuf)-2);
+ while((dcchdr=dcchdr->next)) {
+ if(dcchdr->slen > sizeof(sendbuf)-2) {
+ /* The size of the header is bigger than the size of
+ * the input buffer, so split it up in smaller parts. */
+ flushbuffer(sockfd, sendbuf);
+ bzero(sendbuf, sizeof(sendbuf));
+ j = 0;
+ while(j < dcchdr->slen)
+ {
+ for(i = 0; i < sizeof(sendbuf)-2; i++) {
+ sendbuf[i] = dcchdr->text[j];
+ j++;
+ }
+ flushbuffer(sockfd, sendbuf);
+ bzero(sendbuf, sizeof(sendbuf));
+ }
+ } else if(Ustrlen(sendbuf) + dcchdr->slen > sizeof(sendbuf)-2) {
+ flushbuffer(sockfd, sendbuf);
+ bzero(sendbuf, sizeof(sendbuf));
+ Ustrncpy(sendbuf, dcchdr->text, sizeof(sendbuf)-2);
+ } else {
+ Ustrncat(sendbuf, dcchdr->text, sizeof(sendbuf)-Ustrlen(sendbuf)-2);
+ }
+ }
+
+ /* a blank line separates header from body */
+ Ustrncat(sendbuf, "\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
+ flushbuffer(sockfd, sendbuf);
+ DEBUG(D_acl)
+ debug_printf("\nDCC: ****************************\n%s", sendbuf);
+
+ /* Clear the input buffer */
+ bzero(sendbuf, sizeof(sendbuf));
+
+ /* now send the body */
+ DEBUG(D_acl)
+ debug_printf("DCC: Writing body:\nDCC: ****************************\n");
+ (void)fseek(data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
+ while((fread(sendbuf, 1, sizeof(sendbuf)-1, data_file)) > 0) {
+ flushbuffer(sockfd, sendbuf);
+ bzero(sendbuf, sizeof(sendbuf));
+ }
+ DEBUG(D_acl)
+ debug_printf("\nDCC: ****************************\n");
+
+ /* shutdown() the socket */
+ if(shutdown(sockfd, 1) < 0){
+ DEBUG(D_acl)
+ debug_printf("DCC: Couldn't shutdown socket: %s\n", strerror(errno));
+ log_write(0,LOG_MAIN,"DCC: Couldn't shutdown socket: %s\n", strerror(errno));
+ /* If there is a problem with the shutdown()
+ * defer the mail. */
+ (void)fclose(data_file);
+ return retval;
+ }
+ DEBUG(D_acl)
+ debug_printf("\nDCC: -------------------------\nDCC: Input sent.\nDCC: -------------------------\n");
+
+ /********************************
+ * receiving output from dccifd *
+ ********************************/
+ DEBUG(D_acl)
+ debug_printf("\nDCC: -------------------------------------\nDCC: Now receiving output from server\nDCC: -----------------------------------\n");
+
+ /******************************************************************
+ * We should get 3 lines: *
+ * 1/ First line is overall result: either 'A' for Accept, *
+ * 'R' for Reject, 'S' for accept Some recipients or *
+ * 'T' for a Temporary error. *
+ * 2/ Second line contains the list of Accepted/Rejected *
+ * recipients in the form AARRA (A = accepted, R = rejected). *
+ * 3/ Third line contains the X-DCC header. *
+ ******************************************************************/
+
+ line = 1; /* we start at the first line of the output */
+ j = 0; /* will be used as index for the recipients list */
+ k = 0; /* initializing the index of the X-DCC header: dcc_header_str[k] */
+
+ /* Let's read from the socket until there's nothing left to read */
+ bzero(recvbuf, sizeof(recvbuf));
+ while((resp = read(sockfd, recvbuf, sizeof(recvbuf)-1)) > 0) {
+ /* How much did we get from the socket */
+ c = Ustrlen(recvbuf) + 1;
+ DEBUG(D_acl)
+ debug_printf("DCC: Length of the output buffer is: %d\nDCC: Output buffer is:\nDCC: ------------\nDCC: %s\nDCC: -----------\n", c, recvbuf);
+
+ /* Now let's read each character and see what we've got */
+ for(i = 0; i < c; i++) {
+ /* First check if we reached the end of the line and
+ * then increment the line counter */
+ if(recvbuf[i] == '\n') {
+ line++;
+ }
+ else {
+ /* The first character of the first line is the
+ * overall response. If there's another character
+ * on that line it is not correct. */
+ if(line == 1) {
+ if(i == 0) {
+ /* Now get the value and set the
+ * return value accordingly */
+ if(recvbuf[i] == 'A') {
+ DEBUG(D_acl)
+ debug_printf("DCC: Overall result = A\treturning OK\n");
+ Ustrcpy(dcc_return_text, "Mail accepted by DCC");
+ dcc_result = US"A";
+ retval = OK;
+ }
+ else if(recvbuf[i] == 'R') {
+ DEBUG(D_acl)
+ debug_printf("DCC: Overall result = R\treturning FAIL\n");
+ dcc_result = US"R";
+ retval = FAIL;
+ if(sender_host_name) {
+ log_write(0, LOG_MAIN, "H=%s [%s] F=<%s>: rejected by DCC", sender_host_name, sender_host_address, sender_address);
+ }
+ else {
+ log_write(0, LOG_MAIN, "H=[%s] F=<%s>: rejected by DCC", sender_host_address, sender_address);
+ }
+ Ustrncpy(dcc_return_text, dcc_reject_message, Ustrlen(dcc_reject_message) + 1);
+ }
+ else if(recvbuf[i] == 'S') {
+ DEBUG(D_acl)
+ debug_printf("DCC: Overall result = S\treturning OK\n");
+ Ustrcpy(dcc_return_text, "Not all recipients accepted by DCC");
+ /* Since we're in an ACL we want a global result
+ * so we accept for all */
+ dcc_result = US"A";
+ retval = OK;
+ }
+ else if(recvbuf[i] == 'G') {
+ DEBUG(D_acl)
+ debug_printf("DCC: Overall result = G\treturning FAIL\n");
+ Ustrcpy(dcc_return_text, "Greylisted by DCC");
+ dcc_result = US"G";
+ retval = FAIL;
+ }
+ else if(recvbuf[i] == 'T') {
+ DEBUG(D_acl)
+ debug_printf("DCC: Overall result = T\treturning DEFER\n");
+ retval = DEFER;
+ log_write(0,LOG_MAIN,"Temporary error with DCC: %s\n", recvbuf);
+ Ustrcpy(dcc_return_text, "Temporary error with DCC");
+ dcc_result = US"T";
+ }
+ else {
+ DEBUG(D_acl)
+ debug_printf("DCC: Overall result = something else\treturning DEFER\n");
+ retval = DEFER;
+ log_write(0,LOG_MAIN,"Unknown DCC response: %s\n", recvbuf);
+ Ustrcpy(dcc_return_text, "Unknown DCC response");
+ dcc_result = US"T";
+ }
+ }
+ else {
+ /* We're on the first line but not on the first character,
+ * there must be something wrong. */
+ DEBUG(D_acl) debug_printf("DCC: Line = %d but i = %d != 0"
+ " character is %c - This is wrong!\n", line, i, recvbuf[i]);
+ log_write(0,LOG_MAIN,"Wrong header from DCC, output is %s\n", recvbuf);
+ }
+ }
+ else if(line == 2) {
+ /* On the second line we get a list of
+ * answers for each recipient. We don't care about
+ * it because we're in an acl and take the
+ * global result. */
+ }
+ else if(line > 2) {
+ /* The third and following lines are the X-DCC header,
+ * so we store it in dcc_header_str. */
+ /* check if we don't get more than we can handle */
+ if(k < sizeof(dcc_header_str)) {
+ dcc_header_str[k] = recvbuf[i];
+ k++;
+ }
+ else {
+ DEBUG(D_acl) debug_printf("DCC: We got more output than we can store"
+ " in the X-DCC header. Truncating at 120 characters.\n");
+ }
+ }
+ else {
+ /* Wrong line number. There must be a problem with the output. */
+ DEBUG(D_acl)
+ debug_printf("DCC: Wrong line number in output. Line number is %d\n", line);
+ }
+ }
+ }
+ /* we reinitialize the output buffer before we read again */
+ bzero(recvbuf,sizeof(recvbuf));
+ }
+ /* We have read everything from the socket */
+
+ /* We need to terminate the X-DCC header with a '\n' character. This needs to be k-1
+ * since dcc_header_str[k] contains '\0'. */
+ dcc_header_str[k-1] = '\n';
+
+ /* Now let's sum up what we've got. */
+ DEBUG(D_acl)
+ debug_printf("\nDCC: --------------------------\nDCC: Overall result = %d\nDCC: X-DCC header: %sReturn message: %s\nDCC: dcc_result: %s\n", retval, dcc_header_str, dcc_return_text, dcc_result);
+
+ /* We only add the X-DCC header if it starts with X-DCC */
+ if(!(Ustrncmp(dcc_header_str, "X-DCC", 5))){
+ dcc_header = dcc_header_str;
+ if(dcc_direct_add_header) {
+ header_add(' ' , "%s", dcc_header_str);
+ /* since the MIME ACL already writes the .eml file to disk without DCC Header we've to erase it */
+ unspool_mbox();
+ }
+ }
+ else {
+ DEBUG(D_acl)
+ debug_printf("DCC: Wrong format of the X-DCC header: %s\n", dcc_header_str);
+ }
+
+ /* check if we should add additional headers passed in acl_m_dcc_add_header */
+ if(dcc_direct_add_header) {
+ if (((xtra_hdrs = expand_string(US"$acl_m_dcc_add_header")) != NULL) && (xtra_hdrs[0] != '\0')) {
+ Ustrncpy(dcc_xtra_hdrs, xtra_hdrs, sizeof(dcc_xtra_hdrs) - 2);
+ if (dcc_xtra_hdrs[Ustrlen(dcc_xtra_hdrs)-1] != '\n')
+ Ustrcat(dcc_xtra_hdrs, "\n");
+ header_add(' ', "%s", dcc_xtra_hdrs);
+ DEBUG(D_acl)
+ debug_printf("DCC: adding additional headers in $acl_m_dcc_add_header: %s", dcc_xtra_hdrs);
+ }
+ }
+
+ dcc_ok = 1;
+ /* Now return to exim main process */
+ DEBUG(D_acl)
+ debug_printf("DCC: Before returning to exim main process:\nDCC: return_text = %s - retval = %d\nDCC: dcc_result = %s\n", dcc_return_text, retval, dcc_result);
+
+ (void)fclose(data_file);
+ dcc_rc = retval;
+ return dcc_rc;
+}
+
+#endif
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-21 14:20:10 +0000