1 #include <u.h>
2 #include <libc.h>
3 #include <fcall.h>
4 #include <thread.h>
5 #include <9p.h>
6 
7 /*
8  * Generous estimate of number of fields, including terminal nil pointer
9  */
10 static int
11 ncmdfield(char *p, int n)
12 {
13 	int white, nwhite;
14 	char *ep;
15 	int nf;
16 
17 	if(p == nil)
18 		return 1;
19 
20 	nf = 0;
21 	ep = p+n;
22 	white = 1;	/* first text will start field */
23 	while(p < ep){
24 		nwhite = (strchr(" \t\r\n", *p++ & 0xFF) != 0);	/* UTF is irrelevant */
25 		if(white && !nwhite)	/* beginning of field */
26 			nf++;
27 		white = nwhite;
28 	}
29 	return nf+1;	/* +1 for nil */
30 }
31 
32 /*
33  *  parse a command written to a device
34  */
35 Cmdbuf*
36 parsecmd(char *p, int n)
37 {
38 	Cmdbuf *cb;
39 	int nf;
40 	char *sp;
41 
42 	nf = ncmdfield(p, n);
43 
44 	/* allocate Cmdbuf plus string pointers plus copy of string including \0 */
45 	sp = emalloc9p(sizeof(*cb) + nf * sizeof(char*) + n + 1);
46 	cb = (Cmdbuf*)sp;
47 	cb->f = (char**)(&cb[1]);
48 	cb->buf = (char*)(&cb->f[nf]);
49 
50 	memmove(cb->buf, p, n);
51 
52 	/* dump new line and null terminate */
53 	if(n > 0 && cb->buf[n-1] == '\n')
54 		n--;
55 	cb->buf[n] = '\0';
56 
57 	cb->nf = tokenize(cb->buf, cb->f, nf-1);
58 	cb->f[cb->nf] = nil;
59 
60 	return cb;
61 }
62 
63 /*
64  * Reconstruct original message, for error diagnostic
65  */
66 void
67 respondcmderror(Req *r, Cmdbuf *cb, char *fmt, ...)
68 {
69 	int i;
70 	va_list arg;
71 	char *p, *e;
72 	char err[ERRMAX];
73 
74 	e = err+ERRMAX-10;
75 	va_start(arg, fmt);
76 	p = vseprint(err, e, fmt, arg);
77 	va_end(arg);
78 	p = seprint(p, e, ": \"");
79 	for(i=0; i<cb->nf; i++){
80 		if(i > 0)
81 			p = seprint(p, e, " ");
82 		p = seprint(p, e, "%q", cb->f[i]);
83 	}
84 	strcpy(p, "\"");
85 	respond(r, err);
86 }
87 
88 /*
89  * Look up entry in table
90  */
91 Cmdtab*
92 lookupcmd(Cmdbuf *cb, Cmdtab *ctab, int nctab)
93 {
94 	int i;
95 	Cmdtab *ct;
96 
97 	if(cb->nf == 0){
98 		werrstr("empty control message");
99 		return nil;
100 	}
101 
102 	for(ct = ctab, i=0; i<nctab; i++, ct++){
103 		if(strcmp(ct->cmd, "*") !=0)	/* wildcard always matches */
104 		if(strcmp(ct->cmd, cb->f[0]) != 0)
105 			continue;
106 		if(ct->narg != 0 && ct->narg != cb->nf){
107 			werrstr("bad # args to command");
108 			return nil;
109 		}
110 		return ct;
111 	}
112 
113 	werrstr("unknown control message");
114 	return nil;
115 }