diff options
Diffstat (limited to 'sub-process.c')
-rw-r--r-- | sub-process.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/sub-process.c b/sub-process.c index a3cfab1a9d1..86de8d7bfbc 100644 --- a/sub-process.c +++ b/sub-process.c @@ -105,3 +105,107 @@ int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, co hashmap_add(hashmap, entry); return 0; } + +static int handshake_version(struct child_process *process, + const char *welcome_prefix, int *versions, + int *chosen_version) +{ + int version_scratch; + int i; + char *line; + const char *p; + + if (!chosen_version) + chosen_version = &version_scratch; + + if (packet_write_fmt_gently(process->in, "%s-client\n", + welcome_prefix)) + return error("Could not write client identification"); + for (i = 0; versions[i]; i++) { + if (packet_write_fmt_gently(process->in, "version=%d\n", + versions[i])) + return error("Could not write requested version"); + } + if (packet_flush_gently(process->in)) + return error("Could not write flush packet"); + + if (!(line = packet_read_line(process->out, NULL)) || + !skip_prefix(line, welcome_prefix, &p) || + strcmp(p, "-server")) + return error("Unexpected line '%s', expected %s-server", + line ? line : "<flush packet>", welcome_prefix); + if (!(line = packet_read_line(process->out, NULL)) || + !skip_prefix(line, "version=", &p) || + strtol_i(p, 10, chosen_version)) + return error("Unexpected line '%s', expected version", + line ? line : "<flush packet>"); + if ((line = packet_read_line(process->out, NULL))) + return error("Unexpected line '%s', expected flush", line); + + /* Check to make sure that the version received is supported */ + for (i = 0; versions[i]; i++) { + if (versions[i] == *chosen_version) + break; + } + if (!versions[i]) + return error("Version %d not supported", *chosen_version); + + return 0; +} + +static int handshake_capabilities(struct child_process *process, + struct subprocess_capability *capabilities, + unsigned int *supported_capabilities) +{ + int i; + char *line; + + for (i = 0; capabilities[i].name; i++) { + if (packet_write_fmt_gently(process->in, "capability=%s\n", + capabilities[i].name)) + return error("Could not write requested capability"); + } + if (packet_flush_gently(process->in)) + return error("Could not write flush packet"); + + while ((line = packet_read_line(process->out, NULL))) { + const char *p; + if (!skip_prefix(line, "capability=", &p)) + continue; + + for (i = 0; + capabilities[i].name && strcmp(p, capabilities[i].name); + i++) + ; + if (capabilities[i].name) { + if (supported_capabilities) + *supported_capabilities |= capabilities[i].flag; + } else { + warning("external filter requested unsupported filter capability '%s'", + p); + } + } + + return 0; +} + +int subprocess_handshake(struct subprocess_entry *entry, + const char *welcome_prefix, + int *versions, + int *chosen_version, + struct subprocess_capability *capabilities, + unsigned int *supported_capabilities) +{ + int retval; + struct child_process *process = &entry->process; + + sigchain_push(SIGPIPE, SIG_IGN); + + retval = handshake_version(process, welcome_prefix, versions, + chosen_version) || + handshake_capabilities(process, capabilities, + supported_capabilities); + + sigchain_pop(SIGPIPE); + return retval; +} |