diald/sme10/diald-1.0.buffer.patch

diff -ru diald-1.0.orig/buffer.c diald-1.0/buffer.c
--- diald-1.0.orig/buffer.c     2001-06-16 15:51:39.000000000 -0400
+++ diald-1.0/buffer.c  2005-10-04 10:38:22.331362000 -0400
@@ -3,6 +3,7 @@
  *
  * Copyright (c) 1994, 1995, 1996 Eric Schenk.
  * Copyright (c) 1999 Mike Jagdis.
+ * Copyright (c) 2002 Jason Turner.
  * All rights reserved. Please see the file LICENSE which should be
  * distributed with this software for terms of use.
  */
@@ -11,90 +12,195 @@
 
 #include <diald.h>
 
+#define BUFFER_CHUNK_SIZE_MAX 4096
 
-#define B(i) buffer[(i)%buffer_size]
-
-static int oldsize = 0;
-static unsigned char *buffer = 0;
-static int head = 0;
-static int used = 0;
-static int tail = 0;
+#ifndef UINT_MAX
+#define UINT_MAX (~0U)
+#endif
 
-void buffer_init(int *var, char **argv)
-{
-    buffer_size = atoi(*argv);
-    if (buffer_size != oldsize) {
-       if (buffer)
-               free(buffer);
-       buffer = malloc(buffer_size);
-       oldsize = buffer_size;
+struct bpkt_hdr {                      /* Buffered packet header */
+    unsigned long expires;             /* When it expires in uptime secs */
+    unsigned int len;                  /* Length of following packet,
+                                        * up to BUFFER_CHUNK_SIZE_MAX */
+};
+
+static char *buffer = 0;               /* start address of ring buffer */
+static char *buffer_end = 0;           /* end address (+1) of ring buffer */
+static unsigned int true_size = 0;     /* actual size of buffer */
+static unsigned int used = 0;          /* bytes used */
+static unsigned int head = 0;          /* read offset */
+static unsigned int tail = 0;          /* write offset */
+
+/* buffer_setup()
+ * Create/recreate/delete the buffer and setup pointers.
+ * Returns the actual buffer size.
+ * The buffer_size variable is declared in diald.h and is given an initial
+ * value in options.c .
+ */
+static unsigned int buffer_setup() {
+    if ( buffer_size < 0 || buffer_size > UINT_MAX ) {
+       mon_syslog(LOG_ERR,"Ignoring invalid buffer_size request.");
+    } else {
+       /* discard existing buffer and any contents */
+       if (buffer) {
+           free(buffer);
+           buffer = 0;
+       }
+       true_size = 0; used = 0; head = 0; tail = 0;
+       if (buffer_size) {
+           /* create new buffer */
+           if (buffer = malloc(buffer_size)) {
+               true_size = buffer_size;
+               buffer_end = buffer + true_size;
+           } else {
+               mon_syslog(LOG_ERR, "Out of memory! Cannot create ring buffer.");
+               /* This is not fatal. diald will run fine without the buffer. */
+           }
+       }
     }
+    return true_size;
 }
 
+/* buffer_check()
+ * If there is no buffer_size param in the config file, the buffer is not
+ * initially set up!
+ * So call this from forward_buffer() and buffer_packet()
+ */
 static void buffer_check()
 {
-    if (!buffer) {
-       buffer = malloc(buffer_size);
-       oldsize = buffer_size;
+    if (buffer)
+       return;
+    if (!buffer_setup()) {
+       /* if we cannot create a buffer, then disable the feature to avoid
+        * repeated calls.  */
+       buffer_packets = 0;
+       mon_syslog(LOG_WARNING,"No buffer: buffer-packets feature disabled.");
     }
 }
 
+/* buffer_write()
+ * Write data to the ring buffer, adjust tail offset and space used
+ * Should not be called unless sure there is enough free space
+ */
+static void buffer_write(unsigned int count, char *pkt) {
+    char *write_ptr = buffer + tail;
+
+    if (write_ptr + count > buffer_end) {
+       unsigned int count2end = buffer_end - write_ptr;
+       memcpy(write_ptr, pkt, count2end);
+       memcpy(buffer, pkt + count2end, count - count2end);
+    } else {
+       memcpy(write_ptr, pkt, count);
+    }
+    tail = (tail+count)%true_size;
+    used += count;
+}
 
-void buffer_packet(unsigned int len,unsigned char *pkt)
+/* buffer_read()
+ * Read bytes from ring buffer. Do not delete.
+ * Should not be called unless used is positive.
+ */
+static void buffer_read(unsigned int count, char *pkt) {
+    char *read_ptr = buffer + head;
+
+    if (read_ptr + count > buffer_end) {
+       unsigned int count2end = buffer_end - read_ptr;
+       memcpy(pkt, read_ptr, count2end);
+       memcpy(pkt + count2end, buffer, count - count2end);
+    } else {
+       memcpy(pkt, read_ptr, count);
+    }
+}
+
+/* buffer_dispose()
+ * Delete from ring buffer by adjusting read offset
+ */
+static void buffer_dispose(unsigned int count) {
+    head = (head+count)%true_size;
+    used -= count;
+}
+
+/* externally linked functions */
+
+/* buffer_init()
+ * This is called when reading the config file or command line options.
+ * There will be at least one argument, but the arg was not checked to be a
+ * numeric string.
+ */
+void buffer_init(int *var, char **argv)
+{
+    buffer_size = strtol(*argv, NULL, 0);
+    if (buffer_size != true_size)
+       buffer_setup();
+}
+
+/* buffer_packet()
+ * Place packet into the ring.
+ */
+void buffer_packet(unsigned int len, unsigned char *pkt)
 {
-    unsigned int clen;
-    unsigned long stamp;
+    struct bpkt_hdr pkt_hdr;
     unsigned long ctime = timestamp();
+    unsigned int space_needed = len + sizeof(struct bpkt_hdr);
+
+    if (len > BUFFER_CHUNK_SIZE_MAX) {
+       mon_syslog(LOG_WARNING, "Packet too large to buffer: %d", len);
+       return;
+    }
 
     buffer_check();
-    if (len+6 > buffer_size) {
+
+    if (space_needed > true_size) {
        mon_syslog(LOG_NOTICE,
            "Can't buffer packet of length %d, buffer too small",
            len);
        return;
     }
+
+    /* TODO
+     * Add buffer filtering ?
+     * eg. ntp packets do not fare well to long delays
+     * The expires time could also be different for each packet.
+     */
+
     if (buffer_fifo_dispose) {
        /* toss from the front of the buffer till we have space */
-       while (used+len+6 > buffer_size) {
-           clen = (B(head)<<8) | B(head+1);
-           head = (head+6+clen)%buffer_size;
-           used -= (6+clen);
+       while (used + space_needed > true_size) {
+           buffer_read(sizeof(struct bpkt_hdr), (char *)&pkt_hdr);
+           buffer_dispose(sizeof(struct bpkt_hdr) + pkt_hdr.len);
        }
     } else {
+       /* toss out expired packets from front of buffer
+        * Any expired packets in the middle will be killed when forwarding
+        */
        for (;;) {
-           clen = (B(head)<<8) | B(head+1);
-           stamp = (B(head+2)<<24) | (B(head+3)<<16) | (B(head+4)<<8) | B(head+5);
-           if (stamp+buffer_timeout >= ctime)
+           if (!used)
+               break;
+           buffer_read(sizeof(struct bpkt_hdr), (char *)&pkt_hdr);
+           if (pkt_hdr.expires >= ctime)
                break;
-           head = (head+6+clen)%buffer_size;
-           used -= (6+clen);
+           buffer_dispose(sizeof(struct bpkt_hdr) + pkt_hdr.len);
        }
     }
-    if (used+len+6 <= buffer_size) {
-       used = used + 6 + len;
-       B(tail) = (len>>8)&0xff;
-       B(tail+1) = len&0xff;
-       B(tail+2) = (ctime>>24)&0xff;
-       B(tail+3) = (ctime>>16)&0xff;
-       B(tail+4) = (ctime>>8)&0xff;
-       B(tail+5) = ctime&0xff;
-       tail = (tail+6)%buffer_size;
-       while (len--) {
-           buffer[tail] = *pkt++;
-           tail = (tail+1)%buffer_size;
-       }
+    if (used + space_needed <= true_size) {
+       pkt_hdr.len = len;
+       pkt_hdr.expires = ctime + buffer_timeout;
+       buffer_write(sizeof(struct bpkt_hdr), (char *)&pkt_hdr);
+       buffer_write(len, pkt);
     } else {
        mon_syslog(LOG_NOTICE,
            "Can't buffer packet of length %d, only %d bytes available.",
-           len,buffer_size-(used+6));
+           len, true_size - ( used + sizeof(struct bpkt_hdr) ) );
     }
 }
 
+/* forward_buffer()
+ * Clears ring buffer and sends unexpired packets on their way.
+ */
 void forward_buffer()
 {
+    struct bpkt_hdr pkt_hdr;
     int forwarding = 0;
-    unsigned int clen, i;
-    unsigned long stamp;
     unsigned long ctime = timestamp();
     struct sockaddr_pkt sp;
 #ifdef HAVE_AF_PACKET
@@ -102,7 +208,7 @@
 #endif
     struct sockaddr *to;
     size_t to_len;
-    unsigned char pkt[4096];
+    char pkt[BUFFER_CHUNK_SIZE_MAX];
 
 #ifdef __linux__
     /* If we are using dynamic addresses we need to know whether we
@@ -141,19 +247,19 @@
     }
 
     while (used > 0) {
-       clen = (B(head)<<8) | B(head+1);
-       stamp = (B(head+2)<<24) | (B(head+3)<<16) | (B(head+4)<<8) | B(head+5);
-        if (stamp+buffer_timeout >= ctime) {
+       buffer_read(sizeof(struct bpkt_hdr), (char *)&pkt_hdr);
+       buffer_dispose(sizeof(struct bpkt_hdr));
+        if (pkt_hdr.expires >= ctime) {
            unsigned short wprot;
-           unsigned char *dpkt;
+           char *dpkt;
            unsigned int dlen;
 
-           for (i = 0; i < clen; i++)
-               pkt[i] = B(head+6+i);
+           buffer_read(pkt_hdr.len, pkt);
 
+           /* strip off the protocol from the raw packet */
            wprot = *(unsigned short *)pkt;
            dpkt = pkt + sizeof(unsigned short);
-           dlen = clen - sizeof(unsigned short);
+           dlen = pkt_hdr.len - sizeof(unsigned short);
 
            /* If we are using dynamic addresses and forwarding traffic
             * we send the packet back in to the kernel on the proxy so
@@ -180,7 +286,6 @@
                    mon_syslog(LOG_ERR,"Error forwarding data packet to physical device from buffer: %m");
            }
        }
-       head = (head+6+clen)%buffer_size;
-       used -= (6+clen);
+       buffer_dispose(pkt_hdr.len);
     }
 }
1	diff -ru diald-1.0.orig/buffer.c diald-1.0/buffer.c
2	--- diald-1.0.orig/buffer.c 2001-06-16 15:51:39.000000000 -0400
3	+++ diald-1.0/buffer.c 2005-10-04 10:38:22.331362000 -0400
4	@@ -3,6 +3,7 @@
5	*
6	* Copyright (c) 1994, 1995, 1996 Eric Schenk.
7	* Copyright (c) 1999 Mike Jagdis.
8	+ * Copyright (c) 2002 Jason Turner.
9	* All rights reserved. Please see the file LICENSE which should be
10	* distributed with this software for terms of use.
11	*/
12	@@ -11,90 +12,195 @@
13
14	#include <diald.h>
15
16	+#define BUFFER_CHUNK_SIZE_MAX 4096
17
18	-#define B(i) buffer[(i)%buffer_size]
19	-
20	-static int oldsize = 0;
21	-static unsigned char *buffer = 0;
22	-static int head = 0;
23	-static int used = 0;
24	-static int tail = 0;
25	+#ifndef UINT_MAX
26	+#define UINT_MAX (~0U)
27	+#endif
28
29	-void buffer_init(int var, char *argv)
30	-{
31	- buffer_size = atoi(*argv);
32	- if (buffer_size != oldsize) {
33	- if (buffer)
34	- free(buffer);
35	- buffer = malloc(buffer_size);
36	- oldsize = buffer_size;
37	+struct bpkt_hdr { /* Buffered packet header */
38	+ unsigned long expires; /* When it expires in uptime secs */
39	+ unsigned int len; /* Length of following packet,
40	+ * up to BUFFER_CHUNK_SIZE_MAX */
41	+};
42	+
43	+static char buffer = 0; / start address of ring buffer */
44	+static char buffer_end = 0; / end address (+1) of ring buffer */
45	+static unsigned int true_size = 0; /* actual size of buffer */
46	+static unsigned int used = 0; /* bytes used */
47	+static unsigned int head = 0; /* read offset */
48	+static unsigned int tail = 0; /* write offset */
49	+
50	+/* buffer_setup()
51	+ * Create/recreate/delete the buffer and setup pointers.
52	+ * Returns the actual buffer size.
53	+ * The buffer_size variable is declared in diald.h and is given an initial
54	+ * value in options.c .
55	+ */
56	+static unsigned int buffer_setup() {
57	+ if ( buffer_size < 0 \|\| buffer_size > UINT_MAX ) {
58	+ mon_syslog(LOG_ERR,"Ignoring invalid buffer_size request.");
59	+ } else {
60	+ /* discard existing buffer and any contents */
61	+ if (buffer) {
62	+ free(buffer);
63	+ buffer = 0;
64	+ }
65	+ true_size = 0; used = 0; head = 0; tail = 0;
66	+ if (buffer_size) {
67	+ /* create new buffer */
68	+ if (buffer = malloc(buffer_size)) {
69	+ true_size = buffer_size;
70	+ buffer_end = buffer + true_size;
71	+ } else {
72	+ mon_syslog(LOG_ERR, "Out of memory! Cannot create ring buffer.");
73	+ /* This is not fatal. diald will run fine without the buffer. */
74	+ }
75	+ }
76	}
77	+ return true_size;
78	}
79
80	+/* buffer_check()
81	+ * If there is no buffer_size param in the config file, the buffer is not
82	+ * initially set up!
83	+ * So call this from forward_buffer() and buffer_packet()
84	+ */
85	static void buffer_check()
86	{
87	- if (!buffer) {
88	- buffer = malloc(buffer_size);
89	- oldsize = buffer_size;
90	+ if (buffer)
91	+ return;
92	+ if (!buffer_setup()) {
93	+ /* if we cannot create a buffer, then disable the feature to avoid
94	+ * repeated calls. */
95	+ buffer_packets = 0;
96	+ mon_syslog(LOG_WARNING,"No buffer: buffer-packets feature disabled.");
97	}
98	}
99
100	+/* buffer_write()
101	+ * Write data to the ring buffer, adjust tail offset and space used
102	+ * Should not be called unless sure there is enough free space
103	+ */
104	+static void buffer_write(unsigned int count, char *pkt) {
105	+ char *write_ptr = buffer + tail;
106	+
107	+ if (write_ptr + count > buffer_end) {
108	+ unsigned int count2end = buffer_end - write_ptr;
109	+ memcpy(write_ptr, pkt, count2end);
110	+ memcpy(buffer, pkt + count2end, count - count2end);
111	+ } else {
112	+ memcpy(write_ptr, pkt, count);
113	+ }
114	+ tail = (tail+count)%true_size;
115	+ used += count;
116	+}
117
118	-void buffer_packet(unsigned int len,unsigned char *pkt)
119	+/* buffer_read()
120	+ * Read bytes from ring buffer. Do not delete.
121	+ * Should not be called unless used is positive.
122	+ */
123	+static void buffer_read(unsigned int count, char *pkt) {
124	+ char *read_ptr = buffer + head;
125	+
126	+ if (read_ptr + count > buffer_end) {
127	+ unsigned int count2end = buffer_end - read_ptr;
128	+ memcpy(pkt, read_ptr, count2end);
129	+ memcpy(pkt + count2end, buffer, count - count2end);
130	+ } else {
131	+ memcpy(pkt, read_ptr, count);
132	+ }
133	+}
134	+
135	+/* buffer_dispose()
136	+ * Delete from ring buffer by adjusting read offset
137	+ */
138	+static void buffer_dispose(unsigned int count) {
139	+ head = (head+count)%true_size;
140	+ used -= count;
141	+}
142	+
143	+/* externally linked functions */
144	+
145	+/* buffer_init()
146	+ * This is called when reading the config file or command line options.
147	+ * There will be at least one argument, but the arg was not checked to be a
148	+ * numeric string.
149	+ */
150	+void buffer_init(int var, char *argv)
151	+{
152	+ buffer_size = strtol(*argv, NULL, 0);
153	+ if (buffer_size != true_size)
154	+ buffer_setup();
155	+}
156	+
157	+/* buffer_packet()
158	+ * Place packet into the ring.
159	+ */
160	+void buffer_packet(unsigned int len, unsigned char *pkt)
161	{
162	- unsigned int clen;
163	- unsigned long stamp;
164	+ struct bpkt_hdr pkt_hdr;
165	unsigned long ctime = timestamp();
166	+ unsigned int space_needed = len + sizeof(struct bpkt_hdr);
167	+
168	+ if (len > BUFFER_CHUNK_SIZE_MAX) {
169	+ mon_syslog(LOG_WARNING, "Packet too large to buffer: %d", len);
170	+ return;
171	+ }
172
173	buffer_check();
174	- if (len+6 > buffer_size) {
175	+
176	+ if (space_needed > true_size) {
177	mon_syslog(LOG_NOTICE,
178	"Can't buffer packet of length %d, buffer too small",
179	len);
180	return;
181	}
182	+
183	+ /* TODO
184	+ * Add buffer filtering ?
185	+ * eg. ntp packets do not fare well to long delays
186	+ * The expires time could also be different for each packet.
187	+ */
188	+
189	if (buffer_fifo_dispose) {
190	/* toss from the front of the buffer till we have space */
191	- while (used+len+6 > buffer_size) {
192	- clen = (B(head)<<8) \| B(head+1);
193	- head = (head+6+clen)%buffer_size;
194	- used -= (6+clen);
195	+ while (used + space_needed > true_size) {
196	+ buffer_read(sizeof(struct bpkt_hdr), (char *)&pkt_hdr);
197	+ buffer_dispose(sizeof(struct bpkt_hdr) + pkt_hdr.len);
198	}
199	} else {
200	+ /* toss out expired packets from front of buffer
201	+ * Any expired packets in the middle will be killed when forwarding
202	+ */
203	for (;;) {
204	- clen = (B(head)<<8) \| B(head+1);
205	- stamp = (B(head+2)<<24) \| (B(head+3)<<16) \| (B(head+4)<<8) \| B(head+5);
206	- if (stamp+buffer_timeout >= ctime)
207	+ if (!used)
208	+ break;
209	+ buffer_read(sizeof(struct bpkt_hdr), (char *)&pkt_hdr);
210	+ if (pkt_hdr.expires >= ctime)
211	break;
212	- head = (head+6+clen)%buffer_size;
213	- used -= (6+clen);
214	+ buffer_dispose(sizeof(struct bpkt_hdr) + pkt_hdr.len);
215	}
216	}
217	- if (used+len+6 <= buffer_size) {
218	- used = used + 6 + len;
219	- B(tail) = (len>>8)&0xff;
220	- B(tail+1) = len&0xff;
221	- B(tail+2) = (ctime>>24)&0xff;
222	- B(tail+3) = (ctime>>16)&0xff;
223	- B(tail+4) = (ctime>>8)&0xff;
224	- B(tail+5) = ctime&0xff;
225	- tail = (tail+6)%buffer_size;
226	- while (len--) {
227	- buffer[tail] = *pkt++;
228	- tail = (tail+1)%buffer_size;
229	- }
230	+ if (used + space_needed <= true_size) {
231	+ pkt_hdr.len = len;
232	+ pkt_hdr.expires = ctime + buffer_timeout;
233	+ buffer_write(sizeof(struct bpkt_hdr), (char *)&pkt_hdr);
234	+ buffer_write(len, pkt);
235	} else {
236	mon_syslog(LOG_NOTICE,
237	"Can't buffer packet of length %d, only %d bytes available.",
238	- len,buffer_size-(used+6));
239	+ len, true_size - ( used + sizeof(struct bpkt_hdr) ) );
240	}
241	}
242
243	+/* forward_buffer()
244	+ * Clears ring buffer and sends unexpired packets on their way.
245	+ */
246	void forward_buffer()
247	{
248	+ struct bpkt_hdr pkt_hdr;
249	int forwarding = 0;
250	- unsigned int clen, i;
251	- unsigned long stamp;
252	unsigned long ctime = timestamp();
253	struct sockaddr_pkt sp;
254	#ifdef HAVE_AF_PACKET
255	@@ -102,7 +208,7 @@
256	#endif
257	struct sockaddr *to;
258	size_t to_len;
259	- unsigned char pkt[4096];
260	+ char pkt[BUFFER_CHUNK_SIZE_MAX];
261
262	#ifdef __linux__
263	/* If we are using dynamic addresses we need to know whether we
264	@@ -141,19 +247,19 @@
265	}
266
267	while (used > 0) {
268	- clen = (B(head)<<8) \| B(head+1);
269	- stamp = (B(head+2)<<24) \| (B(head+3)<<16) \| (B(head+4)<<8) \| B(head+5);
270	- if (stamp+buffer_timeout >= ctime) {
271	+ buffer_read(sizeof(struct bpkt_hdr), (char *)&pkt_hdr);
272	+ buffer_dispose(sizeof(struct bpkt_hdr));
273	+ if (pkt_hdr.expires >= ctime) {
274	unsigned short wprot;
275	- unsigned char *dpkt;
276	+ char *dpkt;
277	unsigned int dlen;
278
279	- for (i = 0; i < clen; i++)
280	- pkt[i] = B(head+6+i);
281	+ buffer_read(pkt_hdr.len, pkt);
282
283	+ /* strip off the protocol from the raw packet */
284	wprot = (unsigned short )pkt;
285	dpkt = pkt + sizeof(unsigned short);
286	- dlen = clen - sizeof(unsigned short);
287	+ dlen = pkt_hdr.len - sizeof(unsigned short);
288
289	/* If we are using dynamic addresses and forwarding traffic
290	* we send the packet back in to the kernel on the proxy so
291	@@ -180,7 +286,6 @@
292	mon_syslog(LOG_ERR,"Error forwarding data packet to physical device from buffer: %m");
293	}
294	}
295	- head = (head+6+clen)%buffer_size;
296	- used -= (6+clen);
297	+ buffer_dispose(pkt_hdr.len);
298	}
299	}