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#include "proto.h"
#include "umbrella.h"
#include "log.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/inet.h>
/* ── Low-level I/O ───────────────────────────────────────────────────────── */
/*
* write_all: keep writing until all bytes are sent or an error occurs.
* Returns 0 on success, -1 on error.
*/
static int write_all(int fd, const void *buf, size_t len) {
const uint8_t *p = buf;
while (len > 0) {
ssize_t n = write(fd, p, len);
if (n < 0) {
if (errno == EINTR) continue;
return -1;
}
p += n;
len -= n;
}
return 0;
}
/*
* read_all: keep reading until exactly len bytes are received or error.
* Returns 0 on success, -1 on error, 1 on clean EOF.
*/
static int read_all(int fd, void *buf, size_t len) {
uint8_t *p = buf;
while (len > 0) {
ssize_t n = read(fd, p, len);
if (n < 0) {
if (errno == EINTR) continue;
return -1;
}
if (n == 0)
return 1; /* clean disconnect */
p += n;
len -= n;
}
return 0;
}
/* ── Protocol ────────────────────────────────────────────────────────────── */
int proto_send(int fd, const char *json) {
uint32_t len = (uint32_t)strlen(json);
uint32_t net_len = htonl(len); /* big-endian on the wire */
if (write_all(fd, &net_len, 4) != 0) {
log_debug("proto_send: write header failed: %s", strerror(errno));
return -1;
}
if (write_all(fd, json, len) != 0) {
log_debug("proto_send: write body failed: %s", strerror(errno));
return -1;
}
return 0;
}
int proto_recv(int fd, char *buf, int buf_size) {
uint32_t net_len;
int r = read_all(fd, &net_len, 4);
if (r != 0) return r == 1 ? 0 : -1; /* 0=disconnect, -1=error */
uint32_t len = ntohl(net_len);
if (len == 0 || (int)len >= buf_size) {
log_warn("proto_recv: bad message length %u", len);
return -1;
}
r = read_all(fd, buf, len);
if (r != 0) return r == 1 ? 0 : -1;
buf[len] = '\0';
return (int)len;
}
/* ── Convenience senders ─────────────────────────────────────────────────── */
int proto_send_ok(int fd) {
return proto_send(fd, "{\"type\":\"ok\"}");
}
int proto_send_error(int fd, const char *message) {
char buf[512];
/* Simple JSON escaping: replace " with \" */
char escaped[256];
int j = 0;
for (int i = 0; message[i] && j < 250; i++) {
if (message[i] == '"') escaped[j++] = '\\';
escaped[j++] = message[i];
}
escaped[j] = '\0';
snprintf(buf, sizeof(buf),
"{\"type\":\"error\",\"message\":\"%s\"}", escaped);
return proto_send(fd, buf);
}
int proto_send_output(int fd, const char *unit_name,
const char *data, int history) {
/*
* We build the JSON manually to avoid a dependency on a JSON library.
* The data field needs escaping — we handle the common cases.
*/
char escaped[RING_BUF_LINE_MAX * 2];
int j = 0;
for (int i = 0; data[i] && j < (int)sizeof(escaped) - 2; i++) {
switch (data[i]) {
case '"': escaped[j++] = '\\'; escaped[j++] = '"'; break;
case '\\': escaped[j++] = '\\'; escaped[j++] = '\\'; break;
case '\n': escaped[j++] = '\\'; escaped[j++] = 'n'; break;
case '\r': escaped[j++] = '\\'; escaped[j++] = 'r'; break;
default: escaped[j++] = data[i]; break;
}
}
escaped[j] = '\0';
char buf[PROTO_MAX_MSG];
snprintf(buf, sizeof(buf),
"{\"type\":\"output\",\"unit\":\"%s\",\"data\":\"%s\","
"\"history\":%s}",
unit_name, escaped, history ? "true" : "false");
return proto_send(fd, buf);
}
/* ── Minimal JSON value extractor ────────────────────────────────────────── */
/*
* Finds "key":"value" or "key":value in a flat JSON object.
* Not a full JSON parser — sufficient for our simple command messages.
*/
int json_get_str(const char *json, const char *key,
char *out, int out_size) {
char needle[MAX_NAME + 4];
snprintf(needle, sizeof(needle), "\"%s\":", key);
const char *p = strstr(json, needle);
if (!p) return 0;
p += strlen(needle);
/* Skip whitespace */
while (*p == ' ' || *p == '\t') p++;
if (*p == '"') {
/* Quoted string */
p++;
int i = 0;
while (*p && *p != '"' && i < out_size - 1) {
if (*p == '\\' && *(p+1)) {
p++;
switch (*p) {
case 'n': out[i++] = '\n'; break;
case 'r': out[i++] = '\r'; break;
case 't': out[i++] = '\t'; break;
default: out[i++] = *p; break;
}
} else {
out[i++] = *p;
}
p++;
}
out[i] = '\0';
return 1;
} else {
/* Unquoted value (number, bool) — read until delimiter */
int i = 0;
while (*p && *p != ',' && *p != '}' && *p != ' ' && i < out_size - 1)
out[i++] = *p++;
out[i] = '\0';
return i > 0 ? 1 : 0;
}
}
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