xref: /plan9-contrib/sys/src/cmd/fossil/9srv.c (revision a6a9e07217f318acf170f99684a55fba5200524f)
1 #include "stdinc.h"
2 
3 #include "9.h"
4 
5 typedef struct Srv Srv;
6 typedef struct Srv {
7 	int	fd;
8 	int	srvfd;
9 	char*	service;
10 	char*	mntpnt;
11 
12 	Srv*	next;
13 	Srv*	prev;
14 } Srv;
15 
16 static struct {
17 	VtLock*	lock;
18 
19 	Srv*	head;
20 	Srv*	tail;
21 } sbox;
22 
23 static int
24 srvFd(char* name, int mode, int fd, char** mntpnt)
25 {
26 	int n, srvfd;
27 	char *p, buf[10];
28 
29 	/*
30 	 * Drop a file descriptor with given name and mode into /srv.
31 	 * Create with ORCLOSE and don't close srvfd so it will be removed
32 	 * automatically on process exit.
33 	 */
34 	p = smprint("/srv/%s", name);
35 	if((srvfd = create(p, ORCLOSE|OWRITE, mode)) < 0){
36 		vtMemFree(p);
37 		p = smprint("#s/%s", name);
38 		if((srvfd = create(p, ORCLOSE|OWRITE, mode)) < 0){
39 			vtSetError("create %s: %r", p);
40 			vtMemFree(p);
41 			return -1;
42 		}
43 	}
44 
45 	n = snprint(buf, sizeof(buf), "%d", fd);
46 	if(write(srvfd, buf, n) < 0){
47 		close(srvfd);
48 		vtSetError("write %s: %r", p);
49 		vtMemFree(p);
50 		return -1;
51 	}
52 
53 	*mntpnt = p;
54 
55 	return srvfd;
56 }
57 
58 static void
59 srvFree(Srv* srv)
60 {
61 	if(srv->prev != nil)
62 		srv->prev->next = srv->next;
63 	else
64 		sbox.head = srv->next;
65 	if(srv->next != nil)
66 		srv->next->prev = srv->prev;
67 	else
68 		sbox.tail = srv->prev;
69 
70 	if(srv->srvfd != -1)
71 		close(srv->srvfd);
72 	vtMemFree(srv->service);
73 	vtMemFree(srv->mntpnt);
74 	vtMemFree(srv);
75 }
76 
77 static Srv*
78 srvAlloc(char* service, int mode, int fd)
79 {
80 	Srv *srv;
81 	int srvfd;
82 	char *mntpnt;
83 
84 	vtLock(sbox.lock);
85 	for(srv = sbox.head; srv != nil; srv = srv->next){
86 		if(strcmp(srv->service, service) != 0)
87 			continue;
88 		vtSetError("srv: already serving '%s'", service);
89 		vtUnlock(sbox.lock);
90 		return nil;
91 	}
92 
93 	if((srvfd = srvFd(service, mode, fd, &mntpnt)) < 0){
94 		vtUnlock(sbox.lock);
95 		return nil;
96 	}
97 	close(fd);
98 
99 	srv = vtMemAllocZ(sizeof(Srv));
100 	srv->srvfd = srvfd;
101 	srv->service = vtStrDup(service);
102 	srv->mntpnt = mntpnt;
103 
104 	if(sbox.tail != nil){
105 		srv->prev = sbox.tail;
106 		sbox.tail->next = srv;
107 	}
108 	else{
109 		sbox.head = srv;
110 		srv->prev = nil;
111 	}
112 	sbox.tail = srv;
113 	vtUnlock(sbox.lock);
114 
115 	return srv;
116 }
117 
118 static int
119 cmdSrv(int argc, char* argv[])
120 {
121 	Srv *srv;
122 	int dflag, fd[2], mode, pflag, r;
123 	char *usage = "usage: srv [-dp] [service]";
124 
125 	dflag = pflag = 0;
126 	mode = 0666;
127 
128 	ARGBEGIN{
129 	default:
130 		return cliError(usage);
131 	case 'd':
132 		dflag = 1;
133 		break;
134 	case 'p':
135 		pflag = 1;
136 		mode = 0600;
137 		break;
138 	}ARGEND
139 
140 	switch(argc){
141 	default:
142 		return cliError(usage);
143 	case 0:
144 		vtRLock(sbox.lock);
145 		for(srv = sbox.head; srv != nil; srv = srv->next)
146 			consPrint("\t%s\t%d\n", srv->service, srv->srvfd);
147 		vtRUnlock(sbox.lock);
148 
149 		return 1;
150 	case 1:
151 		if(!dflag)
152 			break;
153 
154 		vtLock(sbox.lock);
155 		for(srv = sbox.head; srv != nil; srv = srv->next){
156 			if(strcmp(srv->service, argv[0]) != 0)
157 				continue;
158 			srvFree(srv);
159 			break;
160 		}
161 		vtUnlock(sbox.lock);
162 
163 		if(srv == nil){
164 			vtSetError("srv: '%s' not found", argv[0]);
165 			return 0;
166 		}
167 
168 		return 1;
169 	}
170 
171 	if(pipe(fd) < 0){
172 		vtSetError("srv pipe: %r");
173 		return 0;
174 	}
175 	if((srv = srvAlloc(argv[0], mode, fd[0])) == nil){
176 		close(fd[0]); close(fd[1]);
177 		return 0;
178 	}
179 
180 	if(pflag)
181 		r = consOpen(fd[1], srv->srvfd, -1);
182 	else
183 		r = (conAlloc(fd[1], srv->mntpnt) != nil);
184 	if(r == 0){
185 		close(fd[1]);
186 		vtLock(sbox.lock);
187 		srvFree(srv);
188 		vtUnlock(sbox.lock);
189 	}
190 
191 	return r;
192 }
193 
194 int
195 srvInit(void)
196 {
197 	sbox.lock = vtLockAlloc();
198 
199 	cliAddCmd("srv", cmdSrv);
200 
201 	return 1;
202 }
203