Merge branch 'issue/55'

log.c

@@ -40,6 +40,8 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <syslog.h>
+#include <assert.h>
+#include <sys/stat.h>
 
 /*
  * Centralized logging code multiplexing thread access to the logger based
@@ -219,6 +221,7 @@ log_connect_close(void)
 logger_t *content_log = NULL;
 static int content_fd = -1; /* if set, we are in single file mode */
 static const char *content_basedir = NULL;
+static const char *content_logspec = NULL;
 
 static int
 log_content_open_singlefile(const char *logfile)
@@ -239,6 +242,13 @@ log_content_open_logdir(const char *basedir)
 	return 0;
 }
 
+static int
+log_content_open_logspec(const char *logspec)
+{
+	content_logspec = logspec;
+	return 0;
+}
+
 static void
 log_content_close_singlefile(void)
 {
@@ -248,17 +258,196 @@ log_content_close_singlefile(void)
 	}
 }
 
+/*
+ * Generate a log path based on the given log spec.
+ * Returns an allocated buffer which must be freed by caller, or NULL on error.
+ */
+#define PATH_BUF_INC	1024
+static char * WUNRES NONNULL(1,2,3)
+log_content_format_pathspec(const char *logspec, char *srcaddr, char *dstaddr,
+                            char *exec_path, char *user, char *group)
+{
+	/* set up buffer to hold our generated file path */
+	size_t path_buflen = PATH_BUF_INC;
+	char *path_buf = malloc(path_buflen);
+	if (path_buf == NULL) {
+		log_err_printf("failed to allocate path buffer\n");
+		return NULL;
+	}
+
+	/* initialize the buffer as an empty C string */
+	path_buf[0] = '\0';
+
+	/* iterate over format specifiers */
+	size_t path_len = 0;
+	for (const char *p = logspec; *p != '\0'; p++) {
+		const char *elem = NULL;
+		size_t elem_len = 0;
+
+		const char iso8601[] =  "%Y%m%dT%H%M%SZ";
+		char timebuf[24]; /* sized for ISO 8601 format */
+
+		/* parse the format string and generate the next path element */
+		switch (*p) {
+		case '%':
+			p++;
+			/* handle format specifiers. */
+			switch (*p) {
+			case '\0':
+				/* unexpected eof; backtrack and discard
+				 * invalid format spec */
+				p--;
+				elem_len = 0;
+				break;
+			case '%':
+				elem = p;
+				elem_len = 1;
+				break;
+			case 'd':
+				elem = dstaddr;
+				elem_len = strlen(dstaddr);
+				break;
+			case 's':
+				elem = srcaddr;
+				elem_len = strlen(srcaddr);
+				break;
+			case 'x':
+				if (exec_path) {
+					char *match = exec_path;
+					while ((match = strchr(match, '/')) != NULL) {
+						match++;
+						elem = match;
+					}
+					elem_len = strlen(elem);
+				} else {
+					elem_len = 0;
+				}
+				break;
+			case 'X':
+				elem = exec_path;
+				elem_len = exec_path ? strlen(exec_path) : 0;
+				break;
+			case 'u':
+				elem = user;
+				elem_len = user ? strlen(user) : 0;
+				break;
+			case 'g':
+				elem = group;
+				elem_len = group ? strlen(group) : 0;
+				break;
+			case 'T': {
+				time_t epoch;
+				struct tm *utc;
+
+				time(&epoch);
+				utc = gmtime(&epoch);
+				strftime(timebuf, sizeof(timebuf), iso8601, utc);
+
+				elem = timebuf;
+				elem_len = sizeof(timebuf);
+				break;
+			}}
+			break;
+		default:
+			elem = p;
+			elem_len = 1;
+			break;
+		}
+
+		/* growing the buffer to fit elem_len + terminating \0 */
+		if (path_buflen - path_len < elem_len + 1) {
+			/* Grow in PATH_BUF_INC chunks.
+			 * Note that the use of `PATH_BUF_INC' provides our
+			 * gauranteed space for a trailing '\0' */
+			path_buflen += elem_len + PATH_BUF_INC;
+			char *newbuf = realloc(path_buf, path_buflen);
+			if (newbuf == NULL) {
+				log_err_printf("failed to reallocate path buffer");
+				free(path_buf);
+				return NULL;
+			}
+			path_buf = newbuf;
+		}
+
+		strncat(path_buf, elem, elem_len);
+		path_len += elem_len;
+	}
+
+	/* apply terminating NUL */
+	assert(path_buflen > path_len);
+	path_buf[path_len] = '\0';
+	return path_buf;
+}
+#undef PATH_BUF_INC
+
 void
-log_content_open(log_content_ctx_t *ctx, char *srcaddr, char *dstaddr)
+log_content_open(log_content_ctx_t *ctx, char *srcaddr, char *dstaddr,
+		 char *exec_path, char *user, char *group)
 {
 	if (ctx->open)
 		return;
 
 	if (content_fd != -1) {
+		/* single-file content log (-L) */
 		ctx->fd = content_fd;
 		asprintf(&ctx->header_in, "%s -> %s", srcaddr, dstaddr);
 		asprintf(&ctx->header_out, "%s -> %s", dstaddr, srcaddr);
+	} else if (content_logspec) {
+		/* per-connection-file content log with logspec (-F) */
+		char *filename;
+
+		filename = log_content_format_pathspec(content_logspec,
+		                                       srcaddr, dstaddr,
+		                                       exec_path, user, group);
+
+		/* statefully create parent directories by iteratively rewriting
+		 * the path at each directory seperator */
+		char parent[strlen(filename)+1];
+		char *p;
+
+		memcpy(parent, filename, sizeof(parent));
+
+		/* skip leading '/' characters */
+		p = parent;
+		while (*p == '/') p++;
+
+		while ((p = strchr(p, '/')) != NULL) {
+			/* overwrite '/' to terminate the string at the next
+			 * parent directory */
+			*p = '\0';
+
+			struct stat sbuf;
+			if (stat(parent, &sbuf) != 0) {
+				if (mkdir(parent, 0755) != 0) {
+					log_err_printf("Could not create "
+					               "directory '%s': %s\n",
+					               parent, strerror(errno));
+					ctx->fd = -1;
+					return;
+				}
+			} else if (!S_ISDIR(sbuf.st_mode)) {
+				log_err_printf("Failed to open '%s': "
+				               "%s is not a directory\n",
+				               filename, parent);
+				ctx->fd = -1;
+				return;
+			}
+
+			/* replace the overwritten slash */
+			*p = '/';
+			p++;
+
+			/* skip leading '/' characters */
+			while (*p == '/') p++;
+		}
+
+		ctx->fd = open(filename, O_WRONLY|O_APPEND|O_CREAT, 0660);
+		if (ctx->fd == -1) {
+			log_err_printf("Failed to open '%s': %s\n",
+			               filename, strerror(errno));
+		}
 	} else {
+		/* per-connection-file content log (-S) */
 		char filename[1024];
 		char timebuf[24];
 		time_t epoch;
@@ -383,12 +572,14 @@ int
 log_preinit(opts_t *opts)
 {
 	if (opts->contentlog) {
-		if (!opts->contentlogdir) {
+		if (opts->contentlogdir) {
-			if (log_content_open_singlefile(opts->contentlog)
+			if (log_content_open_logdir(opts->contentlog) == -1)
-			    == -1)
+				goto out;
+		} else if (opts->contentlogspec) {
+			if (log_content_open_logspec(opts->contentlog) == -1)
 				goto out;
 		} else {
-			if (log_content_open_logdir(opts->contentlog) == -1)
+			if (log_content_open_singlefile(opts->contentlog) == -1)
 				goto out;
 		}
 		if (!(content_log = logger_new(log_content_writecb))) {

log.h

@@ -64,7 +64,8 @@ typedef struct log_content_ctx {
 	char *header_in;
 	char *header_out;
 } log_content_ctx_t;
-void log_content_open(log_content_ctx_t *, char *, char *) NONNULL(1,2,3);
+void log_content_open(log_content_ctx_t *, char *, char *, char *,
+                      char *, char *) NONNULL(1,2,3);
 void log_content_submit(log_content_ctx_t *, logbuf_t *, int) NONNULL(1,2);
 void log_content_close(log_content_ctx_t *) NONNULL(1);
 

main.c

@@ -138,8 +138,18 @@ main_usage(void)
 "  -j jaildir  chroot() to jaildir (impacts -S and sni, see manual page)\n"
 "  -p pidfile  write pid to pidfile (default: no pid file)\n"
 "  -l logfile  connect log: log one line summary per connection to logfile\n"
-"  -L logfile  content log: full data to file or named pipe (excludes -S)\n"
+"  -L logfile  content log: full data to file or named pipe (excludes -S/-F)\n"
-"  -S logdir   content log: full data to separate files in dir (excludes -L)\n"
+"  -S logdir   content log: full data to separate files in dir (excludes -L/-F)\n"
+"  -F pathspec content log: full data to sep files with %% subst (excl. -L/-S):\n"
+"              %%T - initial connection time as an ISO 8601 UTC timestamp\n"
+"              %%d - dest address:port\n"
+"              %%s - source address:port\n"
+"              %%x - base name of local process (skipped if unavailable)\n"
+"              %%X - full path to local process (skipped if unavailable)\n"
+"              %%u - user name or id of local process (skipped if unavailable)\n"
+"              %%g - group name or id of local process (skipped if unavailable)\n"
+"              %%%% - literal '%%'\n"
+"      e.g.    \"/var/log/sslsplit/%%X/%%u-%%s-%%d-%%T\"\n"
 "  -d          daemon mode: run in background, log error messages to syslog\n"
 "  -D          debug mode: run in foreground, log debug messages on stderr\n"
 "  -V          print version information and exit\n"
@@ -249,7 +259,7 @@ main(int argc, char *argv[])
 	}
 
 	while ((ch = getopt(argc, argv, OPT_g OPT_G OPT_Z
-	                    "k:c:C:K:t:OPs:r:R:e:Eu:m:j:p:l:L:S:dDVh")) != -1) {
+	                    "k:c:C:K:t:OPs:r:R:e:Eu:m:j:p:l:L:S:F:dDVh")) != -1) {
 		switch (ch) {
 			case 'c':
 				if (opts->cacrt)
@@ -473,6 +483,7 @@ main(int argc, char *argv[])
 				if (!opts->contentlog)
 					oom_die(argv0);
 				opts->contentlogdir = 0;
+				opts->contentlogspec = 0;
 				break;
 			case 'S':
 				if (opts->contentlog)
@@ -481,6 +492,16 @@ main(int argc, char *argv[])
 				if (!opts->contentlog)
 					oom_die(argv0);
 				opts->contentlogdir = 1;
+				opts->contentlogspec = 0;
+				break;
+			case 'F':
+				if (opts->contentlog)
+					free(opts->contentlog);
+				opts->contentlog = strdup(optarg);
+				if (!opts->contentlog)
+					oom_die(argv0);
+				opts->contentlogdir = 0;
+				opts->contentlogspec = 1;
 				break;
 			case 'd':
 				opts->detach = 1;
@@ -573,7 +594,7 @@ main(int argc, char *argv[])
 			oom_die(argv0);
 	}
 	if (!opts->dropuser && !geteuid() && !getuid() &&
-	    !opts->contentlogdir) {
+	    !opts->contentlogdir && !opts->contentlogspec) {
 		opts->dropuser = strdup("nobody");
 		if (!opts->dropuser)
 			oom_die(argv0);

opts.h

@@ -75,6 +75,7 @@ typedef struct opts {
 	unsigned int passthrough : 1;
 	unsigned int deny_ocsp : 1;
 	unsigned int contentlogdir : 1;
+	unsigned int contentlogspec : 1;
 	char *ciphers;
 	char *tgcrtdir;
 	char *dropuser;

pxyconn.c

@@ -1580,7 +1580,8 @@ pxy_bev_eventcb(struct bufferevent *bev, short events, void *arg)
 		}
 		if (WANT_CONTENT_LOG(ctx)) {
 			log_content_open(&ctx->logctx, ctx->src_str,
-			                 ctx->dst_str);
+			                 ctx->dst_str, ctx->exec_path,
+			                 ctx->user, ctx->group);
 		}
 
 		/* log connection if we don't analyze any headers */
@@ -1970,8 +1971,9 @@ pxy_conn_setup(evutil_socket_t fd,
 		if (!ctx->src_str)
 			goto memout;
 
-		if (ctx->pid != -1) {
+		/* fetch process info */
-			if (sys_proc_info(ctx->pid, &ctx->exec_path, &ctx->uid, &ctx->gid) == 0) {
+		if (ctx->pid != -1 && sys_proc_info(ctx->pid, &ctx->exec_path, &ctx->uid, &ctx->gid) == 0) {
+			/* fetch user/group names */
 			ctx->user = sys_user_str(ctx->uid);
 			ctx->group = sys_group_str(ctx->gid);
 			if (!ctx->user || !ctx->group) {
@@ -1979,7 +1981,6 @@ pxy_conn_setup(evutil_socket_t fd,
 			}
 		}
 	}
-	}
 
 	/* for SSL, defer dst connection setup to initial_readcb */
 	if (ctx->spec->ssl) {

sslsplit.1

@@ -116,6 +116,14 @@ returned by \fB-E\fP.
 List all supported NAT engines available on the system and exit.  See
 NAT ENGINES for a list of NAT engines currently supported by SSLsplit.
 .TP
+.B \-F \fIlogspec\fP
+Log connection content to separate log files with the given path specification
+(see LOG SPECIFICATIONS below).  For each connection, a log file will be
+written, which will contain both directions of data as transmitted.
+Information about the connection will be contained in the filename only.
+If \fB-F\fP is used with \fB-j\fP, \fIlogspec\fP is relative to \fIjaildir\fP.
+If \fB-F\fP is used with \fB-u\fP, \fIlogspec\fP must be writable by \fIuser\fP.
+.TP
 .B \-g \fIpemfile\fP
 Use Diffie-Hellman group parameters from \fIpemfile\fP for Ephemereal
 Diffie-Hellman (EDH/DHE) cipher suites.  If \fB-g\fP is not given, SSLsplit
@@ -147,8 +155,8 @@ Display help on usage and exit.
 .TP
 .B \-j \fIjaildir\fP
 Change the root directory to \fIjaildir\fP using chroot(2) after opening files.
-Note that this has implications for both \fB-S\fP and for \fBsni\fP
+Note that this has implications for \fB-F\fP, \fB-S\fP, and for \fBsni\fP
-\fIproxyspecs\fP.  The directory given with \fB-S\fP will be relative to
+\fIproxyspecs\fP.  The path given with \fB-S\fP or \fB-F\fP will be relative to
 \fIjaildir\fP since the log files cannot be opened before calling chroot(2).
 Depending on your operating system, you will need to copy files such as
 \fB/etc/resolv.conf\fP to \fIjaildir\fP in order for name resolution to work.
@@ -347,6 +355,39 @@ than the NAT rules redirecting the actual connections.
 Note that when using \fB-j\fP with \fBsni\fP, you may need to prepare
 \fIjaildir\fP to make name resolution work from within the chroot directory.
 .LP
+.SH "LOG SPECIFICATIONS"
+Log specifications are composed of zero or more printf-style directives;
+ordinary characters are included directly in the output path.
+SSLsplit current supports the following directives:
+.TP
+.I %d
+The destination address and port.
+.TP
+.I %s
+The source address and port.
+.TP
+.I %x
+The name of the local process. If process information is unavailable,
+this directive will be omitted from the output path.
+.TP
+.I %X
+The full path of the local process. If process information is unavailable,
+this directive will be omitted from the output path.
+.TP
+.I %u
+The username or numeric uid of the local process. If process information is unavailable,
+this directive will be omitted from the output path.
+.TP
+.I %g
+The group name or numeric gid of the local process. If process information is unavailable,
+this directive will be omitted from the output path.
+.TP
+.I %T
+The initial connection time as an ISO 8601 UTC timestamp.
+.TP
+.I %%
+A literal '%' character.
+.LP
 .SH "NAT ENGINES"
 SSLsplit currently supports the following NAT engines:
 .TP