Initial fork from clamsmtp

3 files changed, 663 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 0000000..208ae67
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,10 @@
+
+sbin_PROGRAMS = proxsmtpd
+
+proxsmtpd_SOURCES = proxsmtpd.c proxsmtpd.h \
+			../common/spio.c ../common/smtppass.c ../common/smtppass.h ../common/sppriv.h \
+			../common/stringx.c ../common/stringx.h ../common/sock_any.c ../common/sock_any.h \
+			../common/usuals.h ../common/compat.c ../common/compat.h
+
+proxsmtpd_CFLAGS = -I${top_srcdir}/common/ -I${top_srcdir}/
+
diff --git a/src/proxsmtpd.c b/src/proxsmtpd.c
new file mode 100644
index 0000000..897faa9
--- /dev/null
+++ b/src/proxsmtpd.c
@@ -0,0 +1,610 @@
+/*
+ * Copyright (c) 2004, Nate Nielsen
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *     * Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the
+ *       following disclaimer.
+ *     * Redistributions in binary form must reproduce the
+ *       above copyright notice, this list of conditions and
+ *       the following disclaimer in the documentation and/or
+ *       other materials provided with the distribution.
+ *     * The names of contributors to this software may not be
+ *       used to endorse or promote products derived from this
+ *       software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ *
+ * CONTRIBUTORS
+ *  Nate Nielsen <nielsen@memberwebs.com>
+ */
+
+#include <sys/types.h>
+#include <sys/param.h>
+
+#include <paths.h>
+#include <ctype.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <errno.h>
+#include <err.h>
+
+#include "usuals.h"
+
+#include "compat.h"
+#include "sock_any.h"
+#include "stringx.h"
+#include "smtppass.h"
+
+/* -----------------------------------------------------------------------
+ *  STRUCTURES
+ */
+
+typedef struct pxstate
+{
+    /* Settings ------------------------------- */
+    const char* command;            /* The command to pipe email through */
+    /* TODO: Timeout for above command */
+    const char* directory;          /* The directory for temp files */
+    int quarantine;                 /* Leave failed files in temp dir */
+    int debug_files;                /* Leave all files in temp dir */
+}
+pxstate_t;
+
+/* -----------------------------------------------------------------------
+ *  STRINGS
+ */
+
+#define CRLF                "\r\n"
+
+XXXXXXXXXXXXXXXXXxx
+#define SMTP_DATAVIRUSOK    "250 Virus Detected; Discarded Email" CRLF
+#define SMTP_DATAVIRUS      "550 Virus Detected; Content Rejected" CRLF
+
+#define DEFAULT_CONFIG      CONF_PREFIX "/proxsmtpd.conf"
+
+#define CFG_FILTER      "FilterCommand"
+#define CFG_DIRECTORY   "TempDirectory"
+#define CFG_QUARANTINE  "Quarantine"
+#define CFG_DEBUGFILES  "DebugFiles"
+
+/* -----------------------------------------------------------------------
+ *  GLOBALS
+ */
+
+clstate_t g_clstate;
+
+/* -----------------------------------------------------------------------
+ *  FORWARD DECLARATIONS
+ */
+
+static void usage();
+static int connect_clam(clctx_t* ctx);
+static int disconnect_clam(clctx_t* ctx);
+static int quarantine_virus(clctx_t* ctx);
+static int transfer_to_cache(clctx_t* ctx);
+static int clam_scan_file(clctx_t* ctx);
+
+/* -----------------------------------------------------------------------
+ *  SIMPLE MACROS
+ */
+
+/* ----------------------------------------------------------------------------------
+ *  STARTUP ETC...
+ */
+
+int main(int argc, char* argv[])
+{
+    const char* configfile = DEFAULT_CONFIG;
+    const char* pidfile = NULL;
+    int dbg_level = -1;
+    int warnargs = 0;
+    int ch = 0;
+    int r;
+    char* t;
+
+    /* Setup some defaults */
+    memset(&g_clstate, 0, sizeof(g_clstate));
+    g_clstate.header = DEFAULT_HEADER;
+    g_clstate.directory = _PATH_TMP;
+
+    /* We need the default to parse into a useable form, so we do this: */
+    r = cb_parse_option(CFG_CLAMADDR, DEFAULT_CLAMAV);
+    ASSERT(r == 1);
+
+    sp_init("clamsmtpd");
+
+    /*
+     * We still accept our old arguments for compatibility reasons.
+     * We fill them into the spstate structure directly
+     */
+
+    /* Parse the arguments nicely */
+    while((ch = getopt(argc, argv, "bc:d:D:f:h:l:m:p:qt:v")) != -1)
+    {
+        switch(ch)
+        {
+        /* COMPAT: Actively reject messages */
+        case 'b':
+            if((r = cb_parse_option(CFG_BOUNCE, "on")) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+            break;
+
+        /* COMPAT: Change the CLAM socket */
+        case 'c':
+            if((r = cb_parse_option(CFG_CLAMADDR, "on")) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+            break;
+
+		/*  Don't daemonize  */
+        case 'd':
+            dbg_level = strtol(optarg, &t, 10);
+            if(*t) /* parse error */
+                errx(1, "invalid debug log level");
+            dbg_level += LOG_ERR;
+            break;
+
+        /* COMPAT: The directory for the files */
+        case 'D':
+            if((r = sp_parse_option(CFG_DIRECTORY, optarg)) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+            break;
+
+        /* The configuration file */
+        case 'f':
+            configfile = optarg;
+            break;
+
+        /* COMPAT: The header to add */
+        case 'h':
+            if((r = cb_parse_option(CFG_HEADER, optarg)) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+            break;
+
+        /* COMPAT: Change our listening port */
+        case 'l':
+            if((r = sp_parse_option("Listen", optarg)) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+            break;
+
+        /* COMPAT: The maximum number of threads */
+        case 'm':
+            if((r = sp_parse_option("MaxConnections", optarg)) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+            break;
+
+        /* Write out a pid file */
+        case 'p':
+            pidfile = optarg;
+            break;
+
+        /* COMPAT: The timeout */
+		case 't':
+            if((r = sp_parse_option("TimeOut", optarg)) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+			break;
+
+        /* COMPAT: Leave virus files in directory */
+        case 'q':
+            if((r = cb_parse_option(CFG_QUARANTINE, "on")) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+            break;
+
+        /* Print version number */
+        case 'v':
+            printf("clamsmtpd (version %s)\n", VERSION);
+            printf("          (config: %s)\n", DEFAULT_CONFIG);
+            exit(0);
+            break;
+
+        /* COMPAT: Leave all files in the tmp directory */
+        case 'X':
+            if((r = cb_parse_option(CFG_DEBUGFILES, "on")) < 0)
+                usage();
+            ASSERT(r == 1);
+            warnargs = 1;
+            break;
+
+        /* Usage information */
+        case '?':
+        default:
+            usage();
+            break;
+		}
+    }
+
+	argc -= optind;
+	argv += optind;
+
+    if(argc > 1)
+        usage();
+    if(argc == 1)
+    {
+        /* COMPAT: The out address */
+        if((r = sp_parse_option("OutAddress", argv[0])) < 0)
+            usage();
+        ASSERT(r == 1);
+        warnargs = 1;
+    }
+
+    if(warnargs)
+        warnx("please use configuration file instead of command-line flags: %s", configfile);
+
+    r = sp_run(configfile, pidfile, dbg_level);
+
+    sp_done();
+
+    return r;
+}
+
+static void usage()
+{
+    fprintf(stderr, "usage: clamsmtpd [-d debuglevel] [-f configfile] [-p pidfile]\n");
+    fprintf(stderr, "       clamsmtpd -v\n");
+    exit(2);
+}
+
+/* ----------------------------------------------------------------------------------
+ *  SP CALLBACKS
+ */
+
+int cb_check_data(spctx_t* sp)
+{
+    int r = 0;
+    clctx_t* ctx = (clctx_t*)sp;
+
+    /* Connect to clamav */
+    if(!spio_valid(&(ctx->clam)))
+        r = connect_clam(ctx);
+
+    /* transfer_to_cache */
+    if(r != -1 && (r = transfer_to_cache(ctx)) > 0)
+
+        /* ClamAV doesn't like empty files */
+        r = clam_scan_file(ctx);
+
+    switch(r)
+    {
+
+    /*
+     * There was an error tell the client. We haven't notified
+     * the server about any of this yet
+     */
+    case -1:
+        if(sp_fail_data(sp, NULL) == -1)
+            return -1;
+        break;
+
+    /*
+     * No virus was found. Now we initiate a connection to the server
+     * and transfer the file to it.
+     */
+    case 0:
+        if(sp_done_data(sp, g_clstate.header) == -1)
+            return -1;
+        break;
+
+    /*
+     * A virus was found, normally we just drop the email. But if
+     * requested we can send a simple message back to our client.
+     * The server doesn't know data was ever sent, and the client can
+     * choose to reset the connection to reuse it if it wants.
+     */
+    case 1:
+        /* Any special post operation actions on the virus */
+        quarantine_virus(ctx);
+
+        if(sp_fail_data(sp, g_clstate.bounce ?
+                            SMTP_DATAVIRUS : SMTP_DATAVIRUSOK) == -1)
+            return -1;
+        break;
+
+    default:
+        ASSERT(0 && "Invalid clam_scan_file return value");
+        break;
+    };
+
+    return 0;
+}
+
+int cb_parse_option(const char* name, const char* value)
+{
+    if(strcasecmp(CFG_CLAMADDR, name) == 0)
+    {
+        if(sock_any_pton(value, &(g_clstate.clamaddr), SANY_OPT_DEFLOCAL) == -1)
+            errx(2, "invalid " CFG_CLAMADDR " socket name: %s", value);
+        g_clstate.clamname = value;
+        return 1;
+    }
+
+    else if(strcasecmp(CFG_HEADER, name) == 0)
+    {
+        g_clstate.header = (const char*)trim_space((char*)value);
+
+        if(strlen(g_clstate.header) == 0)
+            g_clstate.header = NULL;
+
+        return 1;
+    }
+
+    else if(strcasecmp(CFG_DIRECTORY, name) == 0)
+    {
+        g_clstate.directory = value;
+        return 1;
+    }
+
+    else if(strcasecmp(CFG_BOUNCE, name) == 0)
+    {
+        if((g_clstate.bounce = strtob(value)) == -1)
+            errx(2, "invalid value for " CFG_BOUNCE);
+        return 1;
+    }
+
+    else if(strcasecmp(CFG_QUARANTINE, name) == 0)
+    {
+        if((g_clstate.quarantine = strtob(value)) == -1)
+            errx(2, "invalid value for " CFG_BOUNCE);
+        return 1;
+    }
+
+    else if(strcasecmp(CFG_DEBUGFILES, name) == 0)
+    {
+        if((g_clstate.debug_files = strtob(value)) == -1)
+            errx(2, "invalid value for " CFG_DEBUGFILES);
+        return 1;
+    }
+
+    return 0;
+}
+
+spctx_t* cb_new_context()
+{
+    clctx_t* ctx = (clctx_t*)calloc(1, sizeof(clctx_t));
+    if(!ctx)
+    {
+        sp_messagex(NULL, LOG_CRIT, "out of memory");
+        return NULL;
+    }
+
+    /* Initial preparation of the structure */
+    spio_init(&(ctx->clam), "CLAMAV");
+    return &(ctx->sp);
+}
+
+void cb_del_context(spctx_t* sp)
+{
+    clctx_t* ctx = (clctx_t*)sp;
+    ASSERT(sp);
+
+    disconnect_clam(ctx);
+    free(ctx);
+}
+
+/* ----------------------------------------------------------------------------------
+ *  CLAM AV
+ */
+
+static int connect_clam(clctx_t* ctx)
+{
+    int ret = 0;
+    spctx_t* sp = &(ctx->sp);
+
+    ASSERT(ctx);
+    ASSERT(!spio_valid(&(ctx->clam)));
+
+    if(spio_connect(sp, &(ctx->clam), &(g_clstate.clamaddr), g_clstate.clamname) == -1)
+       RETURN(-1);
+
+    spio_read_junk(sp, &(ctx->clam));
+
+    /* Send a session and a check header to ClamAV */
+
+    if(spio_write_data(sp, &(ctx->clam), "SESSION\n") == -1)
+        RETURN(-1);
+
+    spio_read_junk(sp, &(ctx->clam));
+
+/*
+    if(spio_write_data(sp, &(ctx->clam), "PING\n") == -1 ||
+       spio_read_line(sp, &(ctx->clam), CLIO_DISCARD | CLIO_TRIM) == -1)
+        RETURN(-1);
+
+    if(strcmp(sp->line, CONNECT_RESPONSE) != 0)
+    {
+        sp_message(sp, LOG_ERR, "clamd sent an unexpected response: %s", ctx->line);
+        RETURN(-1);
+    }
+*/
+
+cleanup:
+
+    if(ret < 0)
+        spio_disconnect(sp, &(ctx->clam));
+
+    return ret;
+}
+
+static int disconnect_clam(clctx_t* ctx)
+{
+    spctx_t* sp = &(ctx->sp);
+
+    if(!spio_valid(&(ctx->clam)))
+        return 0;
+
+    if(spio_write_data(sp, &(ctx->clam), CLAM_DISCONNECT) != -1)
+        spio_read_junk(sp, &(ctx->clam));
+
+    spio_disconnect(sp, &(ctx->clam));
+    return 0;
+}
+
+static int clam_scan_file(clctx_t* ctx)
+{
+    int len;
+    spctx_t* sp = &(ctx->sp);
+
+    /* Needs to be long enough to hold path names */
+    ASSERT(SP_LINE_LENGTH > MAXPATHLEN + 32);
+
+    strcpy(sp->line, CLAM_SCAN);
+    strcat(sp->line, sp->cachename);
+    strcat(sp->line, "\n");
+
+    if(spio_write_data(sp, &(ctx->clam), sp->line) == -1)
+        return -1;
+
+    len = spio_read_line(sp, &(ctx->clam), SPIO_DISCARD | SPIO_TRIM);
+    if(len == 0)
+    {
+        sp_messagex(sp, LOG_ERR, "clamd disconnected unexpectedly");
+        return -1;
+    }
+
+    if(is_last_word(sp->line, CLAM_OK, KL(CLAM_OK)))
+    {
+        sp_add_log(sp, "status=", "CLEAN");
+        sp_messagex(sp, LOG_DEBUG, "no virus");
+        return 0;
+    }
+
+    if(is_last_word(sp->line, CLAM_FOUND, KL(CLAM_FOUND)))
+    {
+        len = strlen(sp->cachename);
+
+        if(sp->linelen > len)
+            sp_add_log(sp, "status=VIRUS:", sp->line + len + 1);
+        else
+            sp_add_log(sp, "status=", "VIRUS");
+
+        sp_messagex(sp, LOG_DEBUG, "found virus");
+        return 1;
+    }
+
+    if(is_last_word(sp->line, CLAM_ERROR, KL(CLAM_ERROR)))
+    {
+        sp_messagex(sp, LOG_ERR, "clamav error: %s", sp->line);
+        sp_add_log(sp, "status=", "CLAMAV-ERROR");
+        return -1;
+    }
+
+    sp_add_log(sp, "status=", "CLAMAV-ERROR");
+    sp_messagex(sp, LOG_ERR, "unexepected response from clamd: %s", sp->line);
+    return -1;
+}
+
+/* ----------------------------------------------------------------------------------
+ *  TEMP FILE HANDLING
+ */
+
+static int quarantine_virus(clctx_t* ctx)
+{
+    char buf[MAXPATHLEN];
+    spctx_t* sp = &(ctx->sp);
+    char* t;
+
+    if(!g_clstate.quarantine)
+        return 0;
+
+    strlcpy(buf, g_clstate.directory, MAXPATHLEN);
+    strlcat(buf, "/virus.", MAXPATHLEN);
+
+    /* Points to null terminator */
+    t = buf + strlen(buf);
+
+    /*
+     * Yes, I know we're using mktemp. And yet we're doing it in
+     * a safe manner due to the link command below not overwriting
+     * existing files.
+     */
+    for(;;)
+    {
+        /* Null terminate off the ending, and replace with X's for mktemp */
+        *t = 0;
+        strlcat(buf, "XXXXXX", MAXPATHLEN);
+
+        if(!mktemp(buf))
+        {
+            sp_message(sp, LOG_ERR, "couldn't create quarantine file name");
+            return -1;
+        }
+
+        /* Try to link the file over to the temp */
+        if(link(sp->cachename, buf) == -1)
+        {
+            /* We don't want to allow race conditions */
+            if(errno == EEXIST)
+            {
+                sp_message(sp, LOG_WARNING, "race condition when quarantining virus file: %s", buf);
+                continue;
+            }
+
+            sp_message(sp, LOG_ERR, "couldn't quarantine virus file");
+            return -1;
+        }
+
+        break;
+    }
+
+    sp_messagex(sp, LOG_INFO, "quarantined virus file as: %s", buf);
+    return 0;
+}
+
+static int transfer_to_cache(clctx_t* ctx)
+{
+    spctx_t* sp = &(ctx->sp);
+    int r, count = 0;
+    const char* data;
+
+    while((r = sp_read_data(sp, &data)) != 0)
+    {
+        if(r < 0)
+            return -1;  /* Message already printed */
+
+        count += r;
+
+        if((r = sp_write_data(sp, data, r)) < 0)
+            return -1;  /* Message already printed */
+    }
+
+    /* End the caching */
+    if(sp_write_data(sp, NULL, 0) < 0)
+        return -1;
+
+    sp_messagex(sp, LOG_DEBUG, "wrote %d bytes to temp file", count);
+    return count;
+}
+
+
diff --git a/src/proxsmtpd.h b/src/proxsmtpd.h
new file mode 100644
index 0000000..06b2412
--- /dev/null
+++ b/src/proxsmtpd.h
@@ -0,0 +1,43 @@
+/*
+ * Copyright (c) 2004, Nate Nielsen
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *     * Redistributions of source code must retain the above
+ *       copyright notice, this list of conditions and the
+ *       following disclaimer.
+ *     * Redistributions in binary form must reproduce the
+ *       above copyright notice, this list of conditions and
+ *       the following disclaimer in the documentation and/or
+ *       other materials provided with the distribution.
+ *     * The names of contributors to this software may not be
+ *       used to endorse or promote products derived from this
+ *       software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+ * THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ *
+ * CONTRIBUTORS
+ *  Nate Nielsen <nielsen@memberwebs.com>
+ *
+ */
+
+#ifndef __PROXSMTPD_H__
+#define __PROXSMTPD_H__
+
+
+#endif /* __PROXSMTPD_H__ */