xref: /plan9/sys/src/cmd/venti/srv/verifyarena.c (revision f9e1cf08d3be51592e03e639fc848a68dc31a55e)
1 #include "stdinc.h"
2 #include "dat.h"
3 #include "fns.h"
4 
5 static int	verbose;
6 static int	fd;
7 static uchar	*data;
8 static int	blocksize;
9 static int	sleepms;
10 static vlong offset0;
11 
12 void
usage(void)13 usage(void)
14 {
15 	fprint(2, "usage: verifyarena [-b blocksize] [-s ms] [-v] [arenapart [name...]]\n");
16 	threadexitsall(0);
17 }
18 
19 static int
preadblock(uchar * buf,int n,vlong off)20 preadblock(uchar *buf, int n, vlong off)
21 {
22 	int nr, m;
23 
24 	for(nr = 0; nr < n; nr += m){
25 		m = n - nr;
26 		m = pread(fd, &buf[nr], m, offset0+off+nr);
27 		if(m <= 0){
28 			if(m == 0)
29 				werrstr("early eof");
30 			return -1;
31 		}
32 	}
33 	return 0;
34 }
35 
36 static int
readblock(uchar * buf,int n)37 readblock(uchar *buf, int n)
38 {
39 	int nr, m;
40 
41 	for(nr = 0; nr < n; nr += m){
42 		m = n - nr;
43 		m = read(fd, &buf[nr], m);
44 		if(m <= 0){
45 			if(m == 0)
46 				werrstr("early eof");
47 			return -1;
48 		}
49 	}
50 	return 0;
51 }
52 
53 static void
verifyarena(char * name,vlong len)54 verifyarena(char *name, vlong len)
55 {
56 	Arena arena;
57 	ArenaHead head;
58 	DigestState s;
59 	u64int n, e;
60 	u32int bs;
61 	u8int score[VtScoreSize];
62 
63 	fprint(2, "%T verify %s\n", name);
64 
65 	memset(&arena, 0, sizeof arena);
66 	memset(&s, 0, sizeof s);
67 
68 	/*
69 	 * read a little bit, which will include the header
70 	 */
71 	if(readblock(data, HeadSize) < 0){
72 		fprint(2, "%T %s: reading header: %r\n", name);
73 		return;
74 	}
75 	sha1(data, HeadSize, nil, &s);
76 	if(unpackarenahead(&head, data) < 0){
77 		fprint(2, "%T %s: corrupt arena header: %r\n", name);
78 		return;
79 	}
80 	if(head.version != ArenaVersion4 && head.version != ArenaVersion5)
81 		fprint(2, "%T %s: warning: unknown arena version %d\n", name, head.version);
82 	if(len != 0 && len != head.size)
83 		fprint(2, "%T %s: warning: unexpected length %lld != %lld\n", name, head.size, len);
84 	if(strcmp(name, "<stdin>") != 0 && strcmp(head.name, name) != 0)
85 		fprint(2, "%T %s: warning: unexpected name %s\n", name, head.name);
86 
87 	/*
88 	 * now we know how much to read
89 	 * read everything but the last block, which is special
90 	 */
91 	e = head.size - head.blocksize;
92 	bs = blocksize;
93 	for(n = HeadSize; n < e; n += bs){
94 		if(n + bs > e)
95 			bs = e - n;
96 		if(readblock(data, bs) < 0){
97 			fprint(2, "%T %s: read data: %r\n", name);
98 			return;
99 		}
100 		sha1(data, bs, nil, &s);
101 		if(sleepms)
102 			sleep(sleepms);
103 	}
104 
105 	/*
106 	 * read the last block update the sum.
107 	 * the sum is calculated assuming the slot for the sum is zero.
108 	 */
109 	bs = head.blocksize;
110 	if(readblock(data, bs) < 0){
111 		fprint(2, "%T %s: read last block: %r\n", name);
112 		return;
113 	}
114 	sha1(data, bs-VtScoreSize, nil, &s);
115 	sha1(zeroscore, VtScoreSize, nil, &s);
116 	sha1(nil, 0, score, &s);
117 
118 	/*
119 	 * validity check on the trailer
120 	 */
121 	arena.blocksize = head.blocksize;
122 	if(unpackarena(&arena, data) < 0){
123 		fprint(2, "%T %s: corrupt arena trailer: %r\n", name);
124 		return;
125 	}
126 	scorecp(arena.score, &data[arena.blocksize - VtScoreSize]);
127 
128 	if(namecmp(arena.name, head.name) != 0){
129 		fprint(2, "%T %s: wrong name in trailer: %s vs. %s\n",
130 			name, head.name, arena.name);
131 		return;
132 	}
133 	if(arena.version != head.version){
134 		fprint(2, "%T %s: wrong version in trailer: %d vs. %d\n",
135 			name, head.version, arena.version);
136 		return;
137 	}
138 	arena.size = head.size - 2 * head.blocksize;
139 
140 	/*
141 	 * check for no checksum or the same
142 	 */
143 	if(scorecmp(score, arena.score) == 0)
144 		fprint(2, "%T %s: verified score\n", name);
145 	else if(scorecmp(zeroscore, arena.score) == 0)
146 		fprint(2, "%T %s: unsealed\n", name);
147 	else{
148 		fprint(2, "%T %s: mismatch checksum - found=%V calculated=%V\n",
149 			name, arena.score, score);
150 		return;
151 	}
152 	printarena(2, &arena);
153 }
154 
155 static int
shouldcheck(char * name,char ** s,int n)156 shouldcheck(char *name, char **s, int n)
157 {
158 	int i;
159 
160 	if(n == 0)
161 		return 1;
162 
163 	for(i=0; i<n; i++){
164 		if(s[i] && strcmp(name, s[i]) == 0){
165 			s[i] = nil;
166 			return 1;
167 		}
168 	}
169 	return 0;
170 }
171 
172 void
threadmain(int argc,char * argv[])173 threadmain(int argc, char *argv[])
174 {
175 	int i, nline;
176 	char *p, *q, *table, *f[10], line[256];
177 	vlong start, stop;
178 	ArenaPart ap;
179 	Part *part;
180 
181 	needzeroscore();
182 	ventifmtinstall();
183 	blocksize = MaxIoSize;
184 	ARGBEGIN{
185 	case 'b':
186 		blocksize = unittoull(EARGF(usage()));
187 		break;
188 	case 's':
189 		sleepms = atoi(EARGF(usage()));
190 		break;
191 	case 'v':
192 		verbose++;
193 		break;
194 	default:
195 		usage();
196 		break;
197 	}ARGEND
198 
199 	data = vtmalloc(blocksize);
200 	if(argc == 0){
201 		fd = 0;
202 		verifyarena("<stdin>", 0);
203 		threadexitsall(nil);
204 	}
205 
206 	if((part = initpart(argv[0], OREAD)) == nil)
207 		sysfatal("open partition %s: %r", argv[0]);
208 	fd = part->fd;
209 	offset0 = part->offset;
210 
211 	if(preadblock(data, 8192, PartBlank) < 0)
212 		sysfatal("read arena part header: %r");
213 	if(unpackarenapart(&ap, data) < 0)
214 		sysfatal("corrupted arena part header: %r");
215 	fprint(2, "%T # arena part version=%d blocksize=%d arenabase=%d\n",
216 		ap.version, ap.blocksize, ap.arenabase);
217 	ap.tabbase = (PartBlank+HeadSize+ap.blocksize-1)&~(ap.blocksize-1);
218 	ap.tabsize = ap.arenabase - ap.tabbase;
219 	table = malloc(ap.tabsize+1);
220 	if(preadblock((uchar*)table, ap.tabsize, ap.tabbase) < 0)
221 		sysfatal("reading arena part directory: %r");
222 	table[ap.tabsize] = 0;
223 
224 	nline = atoi(table);
225 	p = strchr(table, '\n');
226 	if(p)
227 		p++;
228 	for(i=0; i<nline; i++){
229 		if(p == nil){
230 			fprint(2, "%T warning: unexpected arena table end\n");
231 			break;
232 		}
233 		q = strchr(p, '\n');
234 		if(q)
235 			*q++ = 0;
236 		if(strlen(p) >= sizeof line){
237 			fprint(2, "%T warning: long arena table line: %s\n", p);
238 			p = q;
239 			continue;
240 		}
241 		strcpy(line, p);
242 		memset(f, 0, sizeof f);
243 		if(tokenize(line, f, nelem(f)) < 3){
244 			fprint(2, "%T warning: bad arena table line: %s\n", p);
245 			p = q;
246 			continue;
247 		}
248 		p = q;
249 		if(shouldcheck(f[0], argv+1, argc-1)){
250 			start = strtoull(f[1], 0, 0);
251 			stop = strtoull(f[2], 0, 0);
252 			if(stop <= start){
253 				fprint(2, "%T %s: bad start,stop %lld,%lld\n", f[0], stop, start);
254 				continue;
255 			}
256 			if(seek(fd, offset0+start, 0) < 0)
257 				fprint(2, "%T %s: seek to start: %r\n", f[0]);
258 			verifyarena(f[0], stop - start);
259 		}
260 	}
261 	for(i=1; i<argc; i++)
262 		if(argv[i] != 0)
263 			fprint(2, "%T %s: did not find arena\n", argv[i]);
264 
265 	threadexitsall(nil);
266 }
267