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
ncmdfield(char * p,int n)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*
parsecmd(char * p,int n)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
respondcmderror(Req * r,Cmdbuf * cb,char * fmt,...)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 quotefmtinstall(); /* just in case */
80 for(i=0; i<cb->nf; i++){
81 if(i > 0)
82 p = seprint(p, e, " ");
83 p = seprint(p, e, "%q", cb->f[i]);
84 }
85 strcpy(p, "\"");
86 respond(r, err);
87 }
88
89 /*
90 * Look up entry in table
91 */
92 Cmdtab*
lookupcmd(Cmdbuf * cb,Cmdtab * ctab,int nctab)93 lookupcmd(Cmdbuf *cb, Cmdtab *ctab, int nctab)
94 {
95 int i;
96 Cmdtab *ct;
97
98 if(cb->nf == 0){
99 werrstr("empty control message");
100 return nil;
101 }
102
103 for(ct = ctab, i=0; i<nctab; i++, ct++){
104 if(strcmp(ct->cmd, "*") !=0) /* wildcard always matches */
105 if(strcmp(ct->cmd, cb->f[0]) != 0)
106 continue;
107 if(ct->narg != 0 && ct->narg != cb->nf){
108 werrstr("bad # args to command");
109 return nil;
110 }
111 return ct;
112 }
113
114 werrstr("unknown control message");
115 return nil;
116 }
117