]>
Commit | Line | Data |
---|---|---|
99605d62 BP |
1 | /* |
2 | * Generic implementation of background process infrastructure. | |
3 | */ | |
4 | #include "sub-process.h" | |
5 | #include "sigchain.h" | |
6 | #include "pkt-line.h" | |
7 | ||
7663cdc8 | 8 | int cmd2process_cmp(const void *unused_cmp_data, |
9ab42958 SB |
9 | const void *entry, |
10 | const void *entry_or_key, | |
7663cdc8 | 11 | const void *unused_keydata) |
99605d62 | 12 | { |
9ab42958 SB |
13 | const struct subprocess_entry *e1 = entry; |
14 | const struct subprocess_entry *e2 = entry_or_key; | |
15 | ||
99605d62 BP |
16 | return strcmp(e1->cmd, e2->cmd); |
17 | } | |
18 | ||
19 | struct subprocess_entry *subprocess_find_entry(struct hashmap *hashmap, const char *cmd) | |
20 | { | |
21 | struct subprocess_entry key; | |
22 | ||
23 | hashmap_entry_init(&key, strhash(cmd)); | |
24 | key.cmd = cmd; | |
25 | return hashmap_get(hashmap, &key, NULL); | |
26 | } | |
27 | ||
4f2a2e9f | 28 | int subprocess_read_status(int fd, struct strbuf *status) |
99605d62 BP |
29 | { |
30 | struct strbuf **pair; | |
31 | char *line; | |
4f2a2e9f BP |
32 | int len; |
33 | ||
99605d62 | 34 | for (;;) { |
4f2a2e9f BP |
35 | len = packet_read_line_gently(fd, NULL, &line); |
36 | if ((len < 0) || !line) | |
99605d62 BP |
37 | break; |
38 | pair = strbuf_split_str(line, '=', 2); | |
39 | if (pair[0] && pair[0]->len && pair[1]) { | |
40 | /* the last "status=<foo>" line wins */ | |
41 | if (!strcmp(pair[0]->buf, "status=")) { | |
42 | strbuf_reset(status); | |
43 | strbuf_addbuf(status, pair[1]); | |
44 | } | |
45 | } | |
46 | strbuf_list_free(pair); | |
47 | } | |
4f2a2e9f BP |
48 | |
49 | return (len < 0) ? len : 0; | |
99605d62 BP |
50 | } |
51 | ||
52 | void subprocess_stop(struct hashmap *hashmap, struct subprocess_entry *entry) | |
53 | { | |
54 | if (!entry) | |
55 | return; | |
56 | ||
57 | entry->process.clean_on_exit = 0; | |
58 | kill(entry->process.pid, SIGTERM); | |
59 | finish_command(&entry->process); | |
60 | ||
61 | hashmap_remove(hashmap, entry, NULL); | |
62 | } | |
63 | ||
64 | static void subprocess_exit_handler(struct child_process *process) | |
65 | { | |
66 | sigchain_push(SIGPIPE, SIG_IGN); | |
67 | /* Closing the pipe signals the subprocess to initiate a shutdown. */ | |
68 | close(process->in); | |
69 | close(process->out); | |
70 | sigchain_pop(SIGPIPE); | |
71 | /* Finish command will wait until the shutdown is complete. */ | |
72 | finish_command(process); | |
73 | } | |
74 | ||
75 | int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, const char *cmd, | |
76 | subprocess_start_fn startfn) | |
77 | { | |
78 | int err; | |
79 | struct child_process *process; | |
80 | const char *argv[] = { cmd, NULL }; | |
81 | ||
82 | entry->cmd = cmd; | |
83 | process = &entry->process; | |
84 | ||
85 | child_process_init(process); | |
86 | process->argv = argv; | |
87 | process->use_shell = 1; | |
88 | process->in = -1; | |
89 | process->out = -1; | |
90 | process->clean_on_exit = 1; | |
91 | process->clean_on_exit_handler = subprocess_exit_handler; | |
92 | ||
93 | err = start_command(process); | |
94 | if (err) { | |
95 | error("cannot fork to run subprocess '%s'", cmd); | |
96 | return err; | |
97 | } | |
98 | ||
99 | hashmap_entry_init(entry, strhash(cmd)); | |
100 | ||
101 | err = startfn(entry); | |
102 | if (err) { | |
103 | error("initialization for subprocess '%s' failed", cmd); | |
104 | subprocess_stop(hashmap, entry); | |
105 | return err; | |
106 | } | |
107 | ||
108 | hashmap_add(hashmap, entry); | |
109 | return 0; | |
110 | } | |
fa64a2fd JT |
111 | |
112 | static int handshake_version(struct child_process *process, | |
113 | const char *welcome_prefix, int *versions, | |
114 | int *chosen_version) | |
115 | { | |
116 | int version_scratch; | |
117 | int i; | |
118 | char *line; | |
119 | const char *p; | |
120 | ||
121 | if (!chosen_version) | |
122 | chosen_version = &version_scratch; | |
123 | ||
124 | if (packet_write_fmt_gently(process->in, "%s-client\n", | |
125 | welcome_prefix)) | |
126 | return error("Could not write client identification"); | |
127 | for (i = 0; versions[i]; i++) { | |
128 | if (packet_write_fmt_gently(process->in, "version=%d\n", | |
129 | versions[i])) | |
130 | return error("Could not write requested version"); | |
131 | } | |
132 | if (packet_flush_gently(process->in)) | |
133 | return error("Could not write flush packet"); | |
134 | ||
135 | if (!(line = packet_read_line(process->out, NULL)) || | |
136 | !skip_prefix(line, welcome_prefix, &p) || | |
137 | strcmp(p, "-server")) | |
138 | return error("Unexpected line '%s', expected %s-server", | |
139 | line ? line : "<flush packet>", welcome_prefix); | |
140 | if (!(line = packet_read_line(process->out, NULL)) || | |
141 | !skip_prefix(line, "version=", &p) || | |
142 | strtol_i(p, 10, chosen_version)) | |
143 | return error("Unexpected line '%s', expected version", | |
144 | line ? line : "<flush packet>"); | |
145 | if ((line = packet_read_line(process->out, NULL))) | |
146 | return error("Unexpected line '%s', expected flush", line); | |
147 | ||
148 | /* Check to make sure that the version received is supported */ | |
149 | for (i = 0; versions[i]; i++) { | |
150 | if (versions[i] == *chosen_version) | |
151 | break; | |
152 | } | |
153 | if (!versions[i]) | |
154 | return error("Version %d not supported", *chosen_version); | |
155 | ||
156 | return 0; | |
157 | } | |
158 | ||
159 | static int handshake_capabilities(struct child_process *process, | |
160 | struct subprocess_capability *capabilities, | |
161 | unsigned int *supported_capabilities) | |
162 | { | |
163 | int i; | |
164 | char *line; | |
165 | ||
166 | for (i = 0; capabilities[i].name; i++) { | |
167 | if (packet_write_fmt_gently(process->in, "capability=%s\n", | |
168 | capabilities[i].name)) | |
169 | return error("Could not write requested capability"); | |
170 | } | |
171 | if (packet_flush_gently(process->in)) | |
172 | return error("Could not write flush packet"); | |
173 | ||
174 | while ((line = packet_read_line(process->out, NULL))) { | |
175 | const char *p; | |
176 | if (!skip_prefix(line, "capability=", &p)) | |
177 | continue; | |
178 | ||
179 | for (i = 0; | |
180 | capabilities[i].name && strcmp(p, capabilities[i].name); | |
181 | i++) | |
182 | ; | |
183 | if (capabilities[i].name) { | |
184 | if (supported_capabilities) | |
185 | *supported_capabilities |= capabilities[i].flag; | |
186 | } else { | |
187 | warning("external filter requested unsupported filter capability '%s'", | |
188 | p); | |
189 | } | |
190 | } | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | int subprocess_handshake(struct subprocess_entry *entry, | |
196 | const char *welcome_prefix, | |
197 | int *versions, | |
198 | int *chosen_version, | |
199 | struct subprocess_capability *capabilities, | |
200 | unsigned int *supported_capabilities) | |
201 | { | |
202 | int retval; | |
203 | struct child_process *process = &entry->process; | |
204 | ||
205 | sigchain_push(SIGPIPE, SIG_IGN); | |
206 | ||
207 | retval = handshake_version(process, welcome_prefix, versions, | |
208 | chosen_version) || | |
209 | handshake_capabilities(process, capabilities, | |
210 | supported_capabilities); | |
211 | ||
212 | sigchain_pop(SIGPIPE); | |
213 | return retval; | |
214 | } |