udyfi

commit 912e1d583ea18ed2c3ca1d1fd884ed1cce1825d8
parent 02621f745a3a9f8c2a809a8bceededa935c6f6d6
Author: Santtu Lakkala <inz@inz.fi>
Date:   Thu,  6 Jul 2023 12:56:57 +0300

Add error handling and man page

Some error handling for configuration file parsing and shiny new manual
page.

Diffstat:
M
Makefile
 | 
7
+++++--
A
udyfi.8
 | 
118
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
udyfi.c
 | 
30
++++++++++++++++++++++--------

3 files changed, 145 insertions(+), 10 deletions(-)
diff --git a/Makefile b/Makefile
@@ -2,6 +2,7 @@ CFLAGS ?= -Os
 CFLAGS += -W -Wall -std=c99 -pedantic -D_POSIX_C_SOURCE=200809L
 PREFIX ?= /usr/local
 BINDIR := $(PREFIX)/bin
+MANDIR := $(PREFIX)/share/man/man8
 IFADDRS_CFLAGS ?= -DUSE_IFADDRS
 HEADERS = arg.h config.h
 VERSION=0.1.0
@@ -16,8 +17,8 @@ LIBS := -L/usr/local/lib -ltls
 all: udyfi
 
 config.h: config.def.h
-	if test -f "$@"; then echo "Refusing to overwrite old config.h"; false; fi
-	cp $< $@
+	if test -f "$@"; then echo "Refusing to overwrite old config.h; please remove or update manually"; false; fi
+	cp config.def.h $@
 
 udyfi: udyfi.c $(HEADERS)
 	$(CROSS)$(CC) -DVERSION='"$(VERSION)"' $(CFLAGS) $(LIBTLS_CFLAGS) $(OPENSSL_CFLAGS) $(IFADDRS_CFLAGS) $< -o $@ $(LIBS)
@@ -28,3 +29,5 @@ clean:
 install: udyfi
 	install -d $(DESTDIR)$(BINDIR)
 	install udyfi $(DESTDIR)$(BINDIR)
+	install -d $(DESTDIR)$(MANDIR)
+	install udyfi.8 $(DESTDIR)$(MANDIR)
diff --git a/udyfi.8 b/udyfi.8
@@ -0,0 +1,118 @@
+.Dd Jul  6, 2023
+.Dt UDYFI 8
+.Os
+.
+.Sh NAME
+.Nm udyfi
+.Nd dynamic dns updater daemon
+.
+.Sh SYNOPSIS
+.Nm
+.Bk -words
+.Op Fl 4
+.Op Fl 6
+.Op Fl a Ar user-agent string
+.Op Fl d Ar dyndns server
+.Op Fl i Ar interface to bind to
+.Op Fl u Ar dyndns username
+.Op Fl p Ar dyndns password
+.Op Fl F Ar configuration file
+.Op Fl f Ar password file
+.Op Fl c Ar checkip server
+.Op Fl D Ar dyndns port
+.Op Fl C Ar checkip port
+.Op Fl b
+.Op Fl l Ar logfile
+.Op Fl P Ar pidfile
+.Op Fl U Ar run as user
+.Op Fl s
+.Op Fl S
+.Op Fl z
+.Op Fl Z
+.Ar domain names
+.Ek
+.
+.Sh DESCRIPTION
+.Bd -filled
+.Nm
+is a dynamic DNS updater daemon
+.Ed
+.
+.Sh OPTIONS
+udyfi options and default settings
+.Bl -tag -width Ds
+.
+.It Fl 4
+Operate over IPv4 only. (Default: any)
+.
+.It Fl 6
+Operate over IPv6 only. (Default: any)
+.
+.It Fl b
+Fork into background. (Default: don't fork)
+.
+.It Fl l Ar logfile
+Location for a log file (no default).
+.
+.It Fl a Ar user-agent string
+User-agent string used in requests (Default: udyfi/version)
+.
+.It Fl d Ar dyndns server
+Dynamic DNS server to connect to (Default: dy.fi)
+.
+.It Fl i Ar interface to bind to
+Interface or address to connect from (Default: any)
+.
+.It Fl u Ar dyndns username
+Username for the dynamic DNS service
+.
+.It Fl p Ar dyndns password
+Password for the dynamic DNS service
+.
+.It Fl F Ar configuration file
+Read configuration from file
+.
+.It Fl f Ar password file
+Read password from file
+.
+.It Fl c Ar checkip server
+Checkip service to check public IP from (Default: checkip.dy.fi)
+.
+.It Fl D Ar dyndns port
+Dynamic DNS server port (Default: 80 for HTTP, 443 for HTTPS)
+.
+.It Fl C Ar checkip port
+Checkip server port (Default: 80 for HTTP, 443 for HTTPS)
+.
+.It Fl P Ar pidfile
+Write daemon pid to pidfile (Default: none)
+.
+.It Fl U Ar run as user
+Change to user after startup (Default: none)
+.
+.It Fl s
+Connect to dynamic DNS server over HTTPS (Default: yes)
+.
+.It Fl S
+Connect to checkip server over HTTPS (Default: no)
+.
+.It Fl z
+Connect to dynamic DNS server over HTTP (Default: no)
+.
+.It Fl Z
+Connect to checkip server over HTTP (Default: yes)
+.
+.It Ar domain names
+Comma-separated list of domain names to update
+.
+.It
+At minimum, username, password and at least one domain name needs to be
+specified, either on command line, or in a configuration file.
+.
+.Sh CONFIGURATION FILE
+.Bd -filled
+The configuration file is a single-line file consisting of command line
+arguments. The arguments are processed in-place, overriding arguments
+specified before, and overridden by arguments after. Multiple files may
+be read sequentially, but cannot be nested. Basic quotation is supported.
+.
diff --git a/udyfi.c b/udyfi.c
@@ -75,7 +75,7 @@ static char **strsplit(char *s, int *c)
 	char *r = s;
 	char *w = s;
 	char **rv = malloc((n + 1) * sizeof(*rv));
-	enum { NONE, SQUOT = '\'', DQUOT = '"' } state = NONE;
+	enum { NONE, ERR, SQUOT = '\'', DQUOT = '"' } state = NONE;
 
 	rv[0] = s;
 
@@ -108,12 +108,21 @@ static char **strsplit(char *s, int *c)
 			continue;
 
 		case '\\':
-			if (state != SQUOT)
-				r++;
+			if (state != SQUOT) {
+				if (!*++r) {
+					state = ERR;
+					continue;
+				}
+			}
 			break;
 		}
 		*w++ = *r++;
 	}
+
+	if (state != NONE) {
+		free(rv);
+		return NULL;
+	}
 	*w = '\0';
 	rv[n] = NULL;
 	*c = n;
@@ -701,11 +710,11 @@ cfgtoggle:
 				dropuser = EARGF(usage());
 				break;
 			case 'p': {
-				  char *pass = EARGF(usage());
-				  snprintf(password, sizeof(password),
-					   "%s", pass);
-				  memset(pass, 0, strlen(pass));
-				  break;
+				char *pass = EARGF(usage());
+				snprintf(password, sizeof(password),
+					 "%s", pass);
+				memset(pass, 0, strlen(pass));
+				break;
 			}
 			case 'F': {
 				FILE *f;
@@ -744,6 +753,11 @@ cfgtoggle:
 				cfgfile.arg = arg;
 
 				argv = strsplit(data, &argc);
+				if (!argv) {
+					fprintf(stderr, "Failed to parse configuration file\n");
+					free(data);
+					return EXIT_FAILURE;
+				}
 				arg = argv[0];
 				if (*arg != '-')
 					continue;