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-rw-r--r--src/spam.c614
1 files changed, 614 insertions, 0 deletions
diff --git a/src/spam.c b/src/spam.c
new file mode 100644
index 0000000..a68b9bf
--- /dev/null
+++ b/src/spam.c
@@ -0,0 +1,614 @@
+/*************************************************
+* Exim - an Internet mail transport agent *
+*************************************************/
+
+/*
+ * Copyright (c) The Exim Maintainers 2016 - 2022
+ * Copyright (c) Tom Kistner <tom@duncanthrax.net> 2003 - 2015
+ * License: GPL
+ */
+
+/* Code for calling spamassassin's spamd. Called from acl.c. */
+
+#include "exim.h"
+#ifdef WITH_CONTENT_SCAN
+#include "spam.h"
+
+uschar spam_score_buffer[16];
+uschar spam_score_int_buffer[16];
+uschar spam_bar_buffer[128];
+uschar spam_action_buffer[32];
+uschar spam_report_buffer[32600];
+uschar * prev_user_name = NULL;
+int spam_ok = 0;
+int spam_rc = 0;
+uschar *prev_spamd_address_work = NULL;
+
+static const uschar * loglabel = US"spam acl condition:";
+
+
+static int
+spamd_param_init(spamd_address_container *spamd)
+{
+/* default spamd server weight, time and priority value */
+spamd->is_rspamd = FALSE;
+spamd->is_failed = FALSE;
+spamd->weight = SPAMD_WEIGHT;
+spamd->timeout = SPAMD_TIMEOUT;
+spamd->retry = 0;
+spamd->priority = SPAMD_PRIORITY;
+return 0;
+}
+
+
+static int
+spamd_param(const uschar * param, spamd_address_container * spamd)
+{
+static int timesinceday = -1;
+const uschar * s;
+const uschar * name;
+
+/*XXX more clever parsing could discard embedded spaces? */
+
+if (sscanf(CCS param, "pri=%u", &spamd->priority))
+ return 0; /* OK */
+
+if (sscanf(CCS param, "weight=%u", &spamd->weight))
+ {
+ if (spamd->weight == 0) /* this server disabled: skip it */
+ return 1;
+ return 0; /* OK */
+ }
+
+if (Ustrncmp(param, "time=", 5) == 0)
+ {
+ unsigned int start_h = 0, start_m = 0, start_s = 0;
+ unsigned int end_h = 24, end_m = 0, end_s = 0;
+ unsigned int time_start, time_end;
+ const uschar * end_string;
+
+ name = US"time";
+ s = param+5;
+ if ((end_string = Ustrchr(s, '-')))
+ {
+ end_string++;
+ if ( sscanf(CS end_string, "%u.%u.%u", &end_h, &end_m, &end_s) == 0
+ || sscanf(CS s, "%u.%u.%u", &start_h, &start_m, &start_s) == 0
+ )
+ goto badval;
+ }
+ else
+ goto badval;
+
+ if (timesinceday < 0)
+ {
+ time_t now = time(NULL);
+ struct tm *tmp = localtime(&now);
+ timesinceday = tmp->tm_hour*3600 + tmp->tm_min*60 + tmp->tm_sec;
+ }
+
+ time_start = start_h*3600 + start_m*60 + start_s;
+ time_end = end_h*3600 + end_m*60 + end_s;
+
+ if (timesinceday < time_start || timesinceday >= time_end)
+ return 1; /* skip spamd server */
+
+ return 0; /* OK */
+ }
+
+if (Ustrcmp(param, "variant=rspamd") == 0)
+ {
+ spamd->is_rspamd = TRUE;
+ return 0;
+ }
+
+if (Ustrncmp(param, "tmo=", 4) == 0)
+ {
+ int sec = readconf_readtime((s = param+4), '\0', FALSE);
+ name = US"timeout";
+ if (sec < 0)
+ goto badval;
+ spamd->timeout = sec;
+ return 0;
+ }
+
+if (Ustrncmp(param, "retry=", 6) == 0)
+ {
+ int sec = readconf_readtime((s = param+6), '\0', FALSE);
+ name = US"retry";
+ if (sec < 0)
+ goto badval;
+ spamd->retry = sec;
+ return 0;
+ }
+
+log_write(0, LOG_MAIN, "%s warning - invalid spamd parameter: '%s'",
+ loglabel, param);
+return -1; /* syntax error */
+
+badval:
+ log_write(0, LOG_MAIN,
+ "%s warning - invalid spamd %s value: '%s'", loglabel, name, s);
+ return -1; /* syntax error */
+}
+
+
+static int
+spamd_get_server(spamd_address_container ** spamds, int num_servers)
+{
+unsigned int i;
+spamd_address_container * sd;
+long weights;
+unsigned pri;
+
+/* speedup, if we have only 1 server */
+if (num_servers == 1)
+ return (spamds[0]->is_failed ? -1 : 0);
+
+/* scan for highest pri */
+for (pri = 0, i = 0; i < num_servers; i++)
+ {
+ sd = spamds[i];
+ if (!sd->is_failed && sd->priority > pri) pri = sd->priority;
+ }
+
+/* get sum of weights */
+for (weights = 0, i = 0; i < num_servers; i++)
+ {
+ sd = spamds[i];
+ if (!sd->is_failed && sd->priority == pri) weights += sd->weight;
+ }
+if (weights == 0) /* all servers failed */
+ return -1;
+
+for (long rnd = random_number(weights), i = 0; i < num_servers; i++)
+ {
+ sd = spamds[i];
+ if (!sd->is_failed && sd->priority == pri)
+ if ((rnd -= sd->weight) < 0)
+ return i;
+ }
+
+log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s unknown error (memory/cpu corruption?)", loglabel);
+return -1;
+}
+
+
+int
+spam(const uschar **listptr)
+{
+int sep = 0;
+const uschar *list = *listptr;
+uschar *user_name;
+unsigned long mbox_size;
+FILE *mbox_file;
+client_conn_ctx spamd_cctx = {.sock = -1};
+uschar spamd_buffer[32600];
+int i, j, offset, result;
+uschar spamd_version[8];
+uschar spamd_short_result[8];
+uschar spamd_score_char;
+double spamd_threshold, spamd_score, spamd_reject_score;
+int spamd_report_offset;
+uschar *p,*q;
+int override = 0;
+time_t start;
+size_t read, wrote;
+uschar *spamd_address_work;
+spamd_address_container * sd;
+
+/* stop compiler warning */
+result = 0;
+
+/* find the username from the option list */
+if (!(user_name = string_nextinlist(&list, &sep, NULL, 0)))
+ {
+ /* no username given, this means no scanning should be done */
+ return FAIL;
+ }
+
+/* if username is "0" or "false", do not scan */
+if (Ustrcmp(user_name, "0") == 0 || strcmpic(user_name, US"false") == 0)
+ return FAIL;
+
+/* if there is an additional option, check if it is "true" */
+if (strcmpic(list,US"true") == 0)
+ /* in that case, always return true later */
+ override = 1;
+
+/* expand spamd_address if needed */
+if (*spamd_address != '$')
+ spamd_address_work = spamd_address;
+else if (!(spamd_address_work = expand_string(spamd_address)))
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s spamd_address starts with $, but expansion failed: %s",
+ loglabel, expand_string_message);
+ return DEFER;
+ }
+
+DEBUG(D_acl) debug_printf_indent("spamd: addrlist '%s'\n", spamd_address_work);
+
+/* check if previous spamd_address was expanded and has changed. dump cached results if so */
+if ( spam_ok
+ && prev_spamd_address_work != NULL
+ && Ustrcmp(prev_spamd_address_work, spamd_address_work) != 0
+ )
+ spam_ok = 0;
+
+/* if we scanned for this username last time, just return */
+if (spam_ok && Ustrcmp(prev_user_name, user_name) == 0)
+ return override ? OK : spam_rc;
+
+/* make sure the eml mbox file is spooled up */
+
+if (!(mbox_file = spool_mbox(&mbox_size, NULL, NULL)))
+ { /* error while spooling */
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s error while creating mbox spool file", loglabel);
+ return DEFER;
+ }
+
+start = time(NULL);
+
+ {
+ int num_servers = 0;
+ int current_server;
+ uschar * address;
+ const uschar * spamd_address_list_ptr = spamd_address_work;
+ spamd_address_container * spamd_address_vector[32];
+
+ /* Check how many spamd servers we have
+ and register their addresses */
+ sep = 0; /* default colon-sep */
+ while ((address = string_nextinlist(&spamd_address_list_ptr, &sep, NULL, 0)))
+ {
+ const uschar * sublist;
+ int sublist_sep = -(int)' '; /* default space-sep */
+ unsigned args;
+ uschar * s;
+
+ DEBUG(D_acl) debug_printf_indent("spamd: addr entry '%s'\n", address);
+ sd = store_get(sizeof(spamd_address_container), GET_UNTAINTED);
+
+ for (sublist = address, args = 0, spamd_param_init(sd);
+ (s = string_nextinlist(&sublist, &sublist_sep, NULL, 0));
+ args++
+ )
+ {
+ DEBUG(D_acl) debug_printf_indent("spamd: addr parm '%s'\n", s);
+ switch (args)
+ {
+ case 0: sd->hostspec = s;
+ if (*s == '/') args++; /* local; no port */
+ break;
+ case 1: sd->hostspec = string_sprintf("%s %s", sd->hostspec, s);
+ break;
+ default: spamd_param(s, sd);
+ break;
+ }
+ }
+ if (args < 2)
+ {
+ log_write(0, LOG_MAIN,
+ "%s warning - invalid spamd address: '%s'", loglabel, address);
+ continue;
+ }
+
+ spamd_address_vector[num_servers] = sd;
+ if (++num_servers > 31)
+ break;
+ }
+
+ /* check if we have at least one server */
+ if (!num_servers)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s no useable spamd server addresses in spamd_address configuration option.",
+ loglabel);
+ goto defer;
+ }
+
+ current_server = spamd_get_server(spamd_address_vector, num_servers);
+ sd = spamd_address_vector[current_server];
+ for(;;)
+ {
+ uschar * errstr;
+
+ DEBUG(D_acl) debug_printf_indent("spamd: trying server %s\n", sd->hostspec);
+
+ for (;;)
+ {
+ /*XXX could potentially use TFO early-data here */
+ if ( (spamd_cctx.sock = ip_streamsocket(sd->hostspec, &errstr, 5, NULL)) >= 0
+ || sd->retry <= 0
+ )
+ break;
+ DEBUG(D_acl) debug_printf_indent("spamd: server %s: retry conn\n", sd->hostspec);
+ while (sd->retry > 0) sd->retry = sleep(sd->retry);
+ }
+ if (spamd_cctx.sock >= 0)
+ break;
+
+ log_write(0, LOG_MAIN, "%s spamd: %s", loglabel, errstr);
+ sd->is_failed = TRUE;
+
+ current_server = spamd_get_server(spamd_address_vector, num_servers);
+ if (current_server < 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC, "%s all spamd servers failed", loglabel);
+ goto defer;
+ }
+ sd = spamd_address_vector[current_server];
+ }
+ }
+
+(void)fcntl(spamd_cctx.sock, F_SETFL, O_NONBLOCK);
+/* now we are connected to spamd on spamd_cctx.sock */
+if (sd->is_rspamd)
+ {
+ gstring * req_str;
+ const uschar * s;
+
+ req_str = string_append(NULL, 8,
+ "CHECK RSPAMC/1.3\r\nContent-length: ", string_sprintf("%lu\r\n", mbox_size),
+ "Queue-Id: ", message_id,
+ "\r\nFrom: <", sender_address,
+ ">\r\nRecipient-Number: ", string_sprintf("%d\r\n", recipients_count));
+
+ for (int i = 0; i < recipients_count; i++)
+ req_str = string_append(req_str, 3,
+ "Rcpt: <", recipients_list[i].address, ">\r\n");
+ if ((s = expand_string(US"$sender_helo_name")) && *s)
+ req_str = string_append(req_str, 3, "Helo: ", s, "\r\n");
+ if ((s = expand_string(US"$sender_host_name")) && *s)
+ req_str = string_append(req_str, 3, "Hostname: ", s, "\r\n");
+ if (sender_host_address)
+ req_str = string_append(req_str, 3, "IP: ", sender_host_address, "\r\n");
+ if ((s = expand_string(US"$authenticated_id")) && *s)
+ req_str = string_append(req_str, 3, "User: ", s, "\r\n");
+ req_str = string_catn(req_str, US"\r\n", 2);
+ wrote = send(spamd_cctx.sock, req_str->s, req_str->ptr, 0);
+ }
+else
+ { /* spamassassin variant */
+ int n;
+ uschar * s = string_sprintf(
+ "REPORT SPAMC/1.2\r\nUser: %s\r\nContent-length: %ld\r\n\r\n%n",
+ user_name, mbox_size, &n);
+ /* send our request */
+ wrote = send(spamd_cctx.sock, s, n, 0);
+ }
+
+if (wrote == -1)
+ {
+ (void)close(spamd_cctx.sock);
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s spamd %s send failed: %s", loglabel, callout_address, strerror(errno));
+ goto defer;
+ }
+
+/* now send the file */
+/* spamd sometimes accepts connections but doesn't read data off the connection.
+We make the file descriptor non-blocking so that the write will only write
+sufficient data without blocking and we poll the descriptor to make sure that we
+can write without blocking. Short writes are gracefully handled and if the
+whole transaction takes too long it is aborted.
+
+Note: poll() is not supported in OSX 10.2 and is reported to be broken in more
+ recent versions (up to 10.4). Workaround using select() removed 2021/11 (jgh).
+ */
+#ifdef NO_POLL_H
+# error Need poll(2) support
+#endif
+
+(void)fcntl(spamd_cctx.sock, F_SETFL, O_NONBLOCK);
+do
+ {
+ read = fread(spamd_buffer,1,sizeof(spamd_buffer),mbox_file);
+ if (read > 0)
+ {
+ offset = 0;
+again:
+ result = poll_one_fd(spamd_cctx.sock, POLLOUT, 1000);
+ if (result == -1 && errno == EINTR)
+ goto again;
+ else if (result < 1)
+ {
+ if (result == -1)
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s %s on spamd %s socket", loglabel, callout_address, strerror(errno));
+ else
+ {
+ if (time(NULL) - start < sd->timeout)
+ goto again;
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s timed out writing spamd %s, socket", loglabel, callout_address);
+ }
+ (void)close(spamd_cctx.sock);
+ goto defer;
+ }
+
+ wrote = send(spamd_cctx.sock,spamd_buffer + offset,read - offset,0);
+ if (wrote == -1)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s %s on spamd %s socket", loglabel, callout_address, strerror(errno));
+ (void)close(spamd_cctx.sock);
+ goto defer;
+ }
+ if (offset + wrote != read)
+ {
+ offset += wrote;
+ goto again;
+ }
+ }
+ }
+while (!feof(mbox_file) && !ferror(mbox_file));
+
+if (ferror(mbox_file))
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s error reading spool file: %s", loglabel, strerror(errno));
+ (void)close(spamd_cctx.sock);
+ goto defer;
+ }
+
+(void)fclose(mbox_file);
+
+/* we're done sending, close socket for writing */
+if (!sd->is_rspamd)
+ shutdown(spamd_cctx.sock,SHUT_WR);
+
+/* read spamd response using what's left of the timeout. */
+memset(spamd_buffer, 0, sizeof(spamd_buffer));
+offset = 0;
+while ((i = ip_recv(&spamd_cctx,
+ spamd_buffer + offset,
+ sizeof(spamd_buffer) - offset - 1,
+ sd->timeout + start)) > 0)
+ offset += i;
+spamd_buffer[offset] = '\0'; /* guard byte */
+
+/* error handling */
+if (i <= 0 && errno != 0)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s error reading from spamd %s, socket: %s", loglabel, callout_address, strerror(errno));
+ (void)close(spamd_cctx.sock);
+ return DEFER;
+ }
+
+/* reading done */
+(void)close(spamd_cctx.sock);
+
+if (sd->is_rspamd)
+ { /* rspamd variant of reply */
+ int r;
+ if ( (r = sscanf(CS spamd_buffer,
+ "RSPAMD/%7s 0 EX_OK\r\nMetric: default; %7s %lf / %lf / %lf\r\n%n",
+ spamd_version, spamd_short_result, &spamd_score, &spamd_threshold,
+ &spamd_reject_score, &spamd_report_offset)) != 5
+ || spamd_report_offset >= offset /* verify within buffer */
+ )
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s cannot parse spamd %s, output: %d", loglabel, callout_address, r);
+ return DEFER;
+ }
+ /* now parse action */
+ p = &spamd_buffer[spamd_report_offset];
+
+ if (Ustrncmp(p, "Action: ", sizeof("Action: ") - 1) == 0)
+ {
+ p += sizeof("Action: ") - 1;
+ q = &spam_action_buffer[0];
+ while (*p && *p != '\r' && (q - spam_action_buffer) < sizeof(spam_action_buffer) - 1)
+ *q++ = *p++;
+ *q = '\0';
+ }
+ }
+else
+ { /* spamassassin */
+ /* dig in the spamd output and put the report in a multiline header,
+ if requested */
+ if (sscanf(CS spamd_buffer,
+ "SPAMD/%7s 0 EX_OK\r\nContent-length: %*u\r\n\r\n%lf/%lf\r\n%n",
+ spamd_version,&spamd_score,&spamd_threshold,&spamd_report_offset) != 3)
+ {
+ /* try to fall back to pre-2.50 spamd output */
+ if (sscanf(CS spamd_buffer,
+ "SPAMD/%7s 0 EX_OK\r\nSpam: %*s ; %lf / %lf\r\n\r\n%n",
+ spamd_version,&spamd_score,&spamd_threshold,&spamd_report_offset) != 3)
+ {
+ log_write(0, LOG_MAIN|LOG_PANIC,
+ "%s cannot parse spamd %s output", loglabel, callout_address);
+ return DEFER;
+ }
+ }
+
+ Ustrcpy(spam_action_buffer,
+ spamd_score >= spamd_threshold ? US"reject" : US"no action");
+ }
+
+/* Create report. Since this is a multiline string,
+we must hack it into shape first */
+p = &spamd_buffer[spamd_report_offset];
+q = spam_report_buffer;
+while (*p != '\0')
+ {
+ /* skip \r */
+ if (*p == '\r')
+ {
+ p++;
+ continue;
+ }
+ *q++ = *p;
+ if (*p++ == '\n')
+ {
+ /* add an extra space after the newline to ensure
+ that it is treated as a header continuation line */
+ *q++ = ' ';
+ }
+ }
+/* NULL-terminate */
+*q-- = '\0';
+/* cut off trailing leftovers */
+while (*q <= ' ')
+ *q-- = '\0';
+
+spam_report = spam_report_buffer;
+spam_action = spam_action_buffer;
+
+/* create spam bar */
+spamd_score_char = spamd_score > 0 ? '+' : '-';
+j = abs((int)(spamd_score));
+i = 0;
+if (j != 0)
+ while ((i < j) && (i <= MAX_SPAM_BAR_CHARS))
+ spam_bar_buffer[i++] = spamd_score_char;
+else
+ {
+ spam_bar_buffer[0] = '/';
+ i = 1;
+ }
+spam_bar_buffer[i] = '\0';
+spam_bar = spam_bar_buffer;
+
+/* create "float" spam score */
+(void)string_format(spam_score_buffer, sizeof(spam_score_buffer),
+ "%.1f", spamd_score);
+spam_score = spam_score_buffer;
+
+/* create "int" spam score */
+j = (int)((spamd_score + 0.001)*10);
+(void)string_format(spam_score_int_buffer, sizeof(spam_score_int_buffer),
+ "%d", j);
+spam_score_int = spam_score_int_buffer;
+
+/* compare threshold against score */
+spam_rc = spamd_score >= spamd_threshold
+ ? OK /* spam as determined by user's threshold */
+ : FAIL; /* not spam */
+
+/* remember expanded spamd_address if needed */
+if (spamd_address_work != spamd_address)
+ prev_spamd_address_work = string_copy(spamd_address_work);
+
+/* remember user name and "been here" for it */
+prev_user_name = user_name;
+spam_ok = 1;
+
+return override
+ ? OK /* always return OK, no matter what the score */
+ : spam_rc;
+
+defer:
+ (void)fclose(mbox_file);
+ return DEFER;
+}
+
+#endif
+/* vi: aw ai sw=2
+*/
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-03 13:43:40 +0000