X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=blobdiff_plain;f=slip.c;h=e555f471218b710b12ecbe35a075ec0660533cd1;hp=5eb8dbdb1239e72698eb52d0f53d108af2e2f607;hb=ae5ae3bf5c5709938e3a2bb6203094ede8af45e6;hpb=3abd18e85781e00e2b7fc641f29c99e130238abf

diff --git a/slip.c b/slip.c
index 5eb8dbd..e555f47 100644
--- a/slip.c
+++ b/slip.c
@@ -27,11 +27,31 @@ struct slip {
     bool_t ignoring_packet; /* If this packet was corrupt or overlong,
 			       we ignore everything up to the next END */
     netlink_deliver_fn *netlink_to_tunnel;
-    uint32_t local_address;
 };
 
 /* Generic SLIP mangling code */
 
+static void slip_write(int fd, const uint8_t *p, size_t l)
+{
+    while (l) {
+	ssize_t written=write(fd,p,l);
+	if (written<0) {
+	    if (errno==EINTR) {
+		continue;
+	    } else if (iswouldblock(errno)) {
+		lg_perror(0,"slip",0,M_ERR,errno,"write() (packet(s) lost)");
+		return;
+	    } else {
+		fatal_perror("slip_stuff: write()");
+	    }
+	}
+	assert(written>0);
+	assert((size_t)written<=l);
+	p+=written;
+	l-=written;
+    }
+}
+
 static void slip_stuff(struct slip *st, struct buffer_if *buf, int fd)
 {
     uint8_t txbuf[DEFAULT_BUFSIZE];
@@ -57,16 +77,12 @@ static void slip_stuff(struct slip *st, struct buffer_if *buf, int fd)
 	    break;
 	}
 	if ((j+2)>DEFAULT_BUFSIZE) {
-	    if (write(fd,txbuf,j)<0) {
-		fatal_perror("slip_stuff: write()");
-	    }
+	    slip_write(fd,txbuf,j);
 	    j=0;
 	}
     }
     txbuf[j++]=SLIP_END;
-    if (write(fd,txbuf,j)<0) {
-	fatal_perror("slip_stuff: write()");
-    }
+    slip_write(fd,txbuf,j);
     BUF_FREE(buf);
 }
 
@@ -79,6 +95,9 @@ static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
 	int outputchr;
 	enum { OUTPUT_END = 256, OUTPUT_NOTHING = 257 };
 
+	if (!st->buff->size)
+	    buffer_init(st->buff,calculate_max_start_pad());
+
 	if (st->pending_esc) {
 	    st->pending_esc=False;
 	    switch(buf[i]) {
@@ -115,7 +134,7 @@ static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
 	if (st->ignoring_packet) {
 	    if (outputchr == OUTPUT_END) {
 		st->ignoring_packet=False;
-		buffer_init(st->buff,calculate_max_start_pad());
+		st->buff->size=0;
 	    }
 	} else {
 	    if (outputchr == OUTPUT_END) {
@@ -123,9 +142,9 @@ static void slip_unstuff(struct slip *st, uint8_t *buf, uint32_t l)
 		    st->netlink_to_tunnel(&st->nl,st->buff);
 		    BUF_ALLOC(st->buff,"userv_afterpoll");
 		}
-		buffer_init(st->buff,calculate_max_start_pad());
+		st->buff->size=0;
 	    } else if (outputchr != OUTPUT_NOTHING) {
-		if (st->buff->size < st->buff->len) {
+		if (buf_remaining_space(st->buff)) {
 		    buf_append_uint8(st->buff,outputchr);
 		} else {
 		    Message(M_WARNING, "userv_afterpoll: dropping overlong"
@@ -144,8 +163,6 @@ static void slip_init(struct slip *st, struct cloc loc, dict_t *dict,
 	netlink_init(&st->nl,st,loc,dict,
 		     "netlink-userv-ipif",NULL,to_host);
     st->buff=find_cl_if(dict,"buffer",CL_BUFFER,True,"name",loc);
-    st->local_address=string_item_to_ipaddr(
-	dict_find_item(dict,"local-address", True, name, loc),"netlink");
     BUF_ALLOC(st->buff,"slip_init");
     st->pending_esc=False;
     st->ignoring_packet=False;
@@ -170,13 +187,13 @@ static int userv_beforepoll(void *sst, struct pollfd *fds, int *nfds_io,
     struct userv *st=sst;
 
     if (st->rxfd!=-1) {
-	*nfds_io=2;
+	BEFOREPOLL_WANT_FDS(2);
 	fds[0].fd=st->txfd;
 	fds[0].events=0; /* Might want to pick up POLLOUT sometime */
 	fds[1].fd=st->rxfd;
 	fds[1].events=POLLIN;
     } else {
-	*nfds_io=0;
+	BEFOREPOLL_WANT_FDS(0);
     }
     return 0;
 }
@@ -195,7 +212,7 @@ static void userv_afterpoll(void *sst, struct pollfd *fds, int nfds)
     if (fds[1].revents&POLLIN) {
 	l=read(st->rxfd,rxbuf,DEFAULT_BUFSIZE);
 	if (l<0) {
-	    if (errno!=EINTR)
+	    if (errno!=EINTR && !iswouldblock(errno))
 		fatal_perror("%s: userv_afterpoll: read(rxfd)",
 			     st->slip.nl.name);
 	} else if (l==0) {
@@ -210,6 +227,14 @@ static void userv_deliver_to_kernel(void *sst, struct buffer_if *buf)
 {
     struct userv *st=sst;
 
+    if (buf->size > st->slip.nl.mtu) {
+	Message(M_ERR,"%s: packet of size %"PRIu32" exceeds mtu %"PRIu32":"
+		" cannot be injected into kernel, dropped\n",
+		st->slip.nl.name, buf->size, st->slip.nl.mtu);
+	BUF_FREE(buf);
+	return;
+    }
+
     slip_stuff(&st->slip,buf,st->txfd);
 }
 
@@ -222,20 +247,13 @@ static void userv_userv_callback(void *sst, pid_t pid, int status)
 		"(expected %d)\n",pid,st->pid);
 	return;
     }
-    if (!st->expecting_userv_exit) {
-	if (WIFEXITED(status)) {
-	    fatal("%s: userv exited unexpectedly with status %d",
-		  st->slip.nl.name,WEXITSTATUS(status));
-	} else if (WIFSIGNALED(status)) {
-	    fatal("%s: userv exited unexpectedly: uncaught signal %d",
-		  st->slip.nl.name,WTERMSIG(status));
-	} else {
-	    fatal("%s: userv stopped unexpectedly",
-		  st->slip.nl.name);
-	}
+    if (!(st->expecting_userv_exit &&
+	  (!status ||
+	   (WIFSIGNALED(status) && WTERMSIG(status)==SIGTERM)))) {
+	lg_exitstatus(0,st->slip.nl.name,0,
+		      st->expecting_userv_exit ? M_WARNING : M_FATAL,
+		      status,"userv");
     }
-    Message(M_WARNING,"%s: userv subprocess died with status %d\n",
-	    st->slip.nl.name,WEXITSTATUS(status));
     st->pid=0;
 }
 
@@ -254,10 +272,7 @@ static void userv_entry(void *sst)
     dup2(st->in,0);
     dup2(st->out,1);
 
-    /* XXX close all other fds */
     setsid();
-    /* XXX We really should strdup() all of argv[] but because we'll just
-       exit anyway if execvp() fails it doesn't seem worth bothering. */
     execvp(st->path,(char *const*)st->argv);
     perror("userv-entry: execvp()");
     exit(1);
@@ -265,10 +280,9 @@ static void userv_entry(void *sst)
 
 static void userv_invoke_userv(struct userv *st)
 {
-    struct userv_entry_rec *er;
+    struct userv_entry_rec er[1];
     int c_stdin[2];
     int c_stdout[2];
-    string_t addrs;
     string_t nets;
     string_t s;
     struct netlink_client *r;
@@ -284,9 +298,9 @@ static void userv_invoke_userv(struct userv *st)
     /* This is where we actually invoke userv - all the networks we'll
        be using should already have been registered. */
 
-    addrs=safe_malloc(512,"userv_invoke_userv:addrs");
-    snprintf(addrs,512,"%s,%s,%d,slip",
-	     ipaddr_to_string(st->slip.local_address),
+    char addrs[512];
+    snprintf(addrs,sizeof(addrs),"%s,%s,%d,slip",
+	     ipaddr_to_string(st->slip.nl.local_address),
 	     ipaddr_to_string(st->slip.nl.secnet_address),st->slip.nl.mtu);
 
     allnets=ipset_new();
@@ -307,7 +321,6 @@ static void userv_invoke_userv(struct userv *st)
 	s=subnet_to_string(snets->list[i]);
 	strcat(nets,s);
 	strcat(nets,",");
-	free(s);
     }
     nets[strlen(nets)-1]=0;
     subnet_list_free(snets);
@@ -318,17 +331,11 @@ static void userv_invoke_userv(struct userv *st)
     st->slip.pending_esc=False;
 
     /* Invoke userv */
-    if (pipe(c_stdin)!=0) {
-	fatal_perror("userv_invoke_userv: pipe(c_stdin)");
-    }
-    if (pipe(c_stdout)!=0) {
-	fatal_perror("userv_invoke_userv: pipe(c_stdout)");
-    }
+    pipe_cloexec(c_stdin);
+    pipe_cloexec(c_stdout);
     st->txfd=c_stdin[1];
     st->rxfd=c_stdout[0];
 
-    er=safe_malloc(sizeof(*r),"userv_invoke_userv: er");
-
     er->in=c_stdin[0];
     er->out=c_stdout[1];
     /* The arguments are:
@@ -337,7 +344,8 @@ static void userv_invoke_userv(struct userv *st)
        service-name
        local-addr,secnet-addr,mtu,protocol
        route1,route2,... */
-    er->argv=safe_malloc(sizeof(*er->argv)*6,"userv_invoke_userv:argv");
+    const char *er_argv[6];
+    er->argv=er_argv;
     er->argv[0]=st->userv_path;
     er->argv[1]=st->service_user;
     er->argv[2]=st->service_name;
@@ -350,9 +358,6 @@ static void userv_invoke_userv(struct userv *st)
 			er, st, st->slip.nl.name);
     close(er->in);
     close(er->out);
-    free(er->argv);
-    free(er);
-    free(addrs);
     free(nets);
     Message(M_INFO,"%s: userv-ipif pid is %d\n",st->slip.nl.name,st->pid);
     /* Read a single character from the pipe to confirm userv-ipif is
@@ -376,6 +381,8 @@ static void userv_invoke_userv(struct userv *st)
 		  st->slip.nl.name,confirm);
 	}
     }
+    setnonblock(st->txfd);
+    setnonblock(st->rxfd);
 }
 
 static void userv_kill_userv(struct userv *st)
@@ -394,7 +401,7 @@ static void userv_phase_hook(void *sst, uint32_t newphase)
     if (newphase==PHASE_RUN) {
 	userv_invoke_userv(st);
 	/* Register for poll() */
-	register_for_poll(st, userv_beforepoll, userv_afterpoll, 2,
+	register_for_poll(st, userv_beforepoll, userv_afterpoll,
 			  st->slip.nl.name);
     }
     if (newphase==PHASE_SHUTDOWN) {