Fix: Remove compiler warnings (signedness, unused functions, snprintf truncation)

- Cast st_size to uint64_t to match file_size type in server.c
- Remove unused functions: send_one_file, send_file_udp, verify_and_resend
- Reduce rel buffer size to 1024 to prevent snprintf truncation in collect_files

Generated by Mistral Vibe.
Co-Authored-By: Mistral Vibe <vibe@mistral.ai>

src/client.c

@@ -71,153 +71,6 @@ typedef struct {
 static atomic_uint_fast64_t g_bytes_sent = 0;
 static atomic_uint_fast32_t g_files_sent = 0;
 
-// ─── UDP helpers ──────────────────────────────────────────────────────────
-
-static int verify_and_resend(sync_ctx_t *ctx, int file_fd,
-                              uint32_t file_id, uint64_t file_size) {
-    uint32_t total_blocks = (file_size + UDP_PAYLOAD_MAX - 1) / UDP_PAYLOAD_MAX;
-
-    while (1) {
-        uint32_t req = MAGIC_VERIFY;
-        if (writen(ctx->tcp_fd, &req, sizeof(req)) != sizeof(req)) return -1;
-        if (writen(ctx->tcp_fd, &file_id, sizeof(file_id)) != sizeof(file_id)) return -1;
-
-        uint32_t missing = 0;
-        if (readn(ctx->tcp_fd, &missing, sizeof(missing)) != sizeof(missing)) return -1;
-        if (missing == 0) break;
-
-        uint32_t *ids = malloc(missing * sizeof(uint32_t));
-        if (!ids) { perror("malloc"); return -1; }
-        if (readn(ctx->tcp_fd, ids, missing * sizeof(uint32_t))
-                != (ssize_t)(missing * sizeof(uint32_t))) { free(ids); return -1; }
-
-        printf("[thread] Resending %u missing blocks...\n", missing);
-        for (uint32_t i = 0; i < missing; i++) {
-            uint32_t bid = ids[i];
-            if (bid >= total_blocks) continue;
-            uint64_t off = (uint64_t)bid * UDP_PAYLOAD_MAX;
-            if (lseek(file_fd, off, SEEK_SET) == (off_t)-1) { perror("lseek"); continue; }
-
-            char payload[UDP_PAYLOAD_MAX];
-            ssize_t nr = read(file_fd, payload, UDP_PAYLOAD_MAX);
-            if (nr <= 0) continue;
-
-            udp_packet_header_t hdr;
-            hdr.magic        = MAGIC_UDP_DATA;
-            hdr.session_id   = ctx->udp_session_id;
-            hdr.file_id      = file_id;
-            hdr.block_id     = bid;
-            hdr.block_offset = off;
-            hdr.payload_len  = nr;
-
-            char pkt[sizeof(hdr) + UDP_PAYLOAD_MAX];
-            memcpy(pkt, &hdr, sizeof(hdr));
-            memcpy(pkt + sizeof(hdr), payload, nr);
-            sendto(ctx->udp_fd, pkt, sizeof(hdr) + nr, 0,
-                   (struct sockaddr *)&ctx->udp_server_addr,
-                   sizeof(ctx->udp_server_addr));
-        }
-        free(ids);
-    }
-    return 0;
-}
-
-static int send_file_udp(sync_ctx_t *ctx, const char *full_path,
-                          uint32_t file_id, uint64_t file_size) {
-    int fd = open(full_path, O_RDONLY);
-    if (fd < 0) { perror("open"); return -1; }
-
-    uint32_t total = (file_size + UDP_PAYLOAD_MAX - 1) / UDP_PAYLOAD_MAX;
-    printf("[thread] UDP send: %s (%u blocks)\n", full_path, total);
-
-    for (uint32_t bid = 0; bid < total; bid++) {
-        char payload[UDP_PAYLOAD_MAX];
-        ssize_t nr = read(fd, payload, UDP_PAYLOAD_MAX);
-        if (nr <= 0) break;
-
-        udp_packet_header_t hdr;
-        hdr.magic        = MAGIC_UDP_DATA;
-        hdr.session_id   = ctx->udp_session_id;
-        hdr.file_id      = file_id;
-        hdr.block_id     = bid;
-        hdr.block_offset = (uint64_t)bid * UDP_PAYLOAD_MAX;
-        hdr.payload_len  = nr;
-
-        char pkt[sizeof(hdr) + UDP_PAYLOAD_MAX];
-        memcpy(pkt, &hdr, sizeof(hdr));
-        memcpy(pkt + sizeof(hdr), payload, nr);
-        sendto(ctx->udp_fd, pkt, sizeof(hdr) + nr, 0,
-               (struct sockaddr *)&ctx->udp_server_addr,
-               sizeof(ctx->udp_server_addr));
-    }
-
-    int ret = verify_and_resend(ctx, fd, file_id, file_size);
-    close(fd);
-    return ret;
-}
-
-// ─── Send a single file over one connection (TCP or UDP data) ─────────────
-
-static int send_one_file(sync_ctx_t *ctx, const char *full_path,
-                          const char *rel_path) {
-    struct stat st;
-    if (stat(full_path, &st) < 0) { perror("stat"); return -1; }
-
-    file_meta_t meta;
-    meta.magic    = MAGIC_META;
-    meta.name_len = strlen(rel_path);
-    meta.file_size = st.st_size;
-    meta.mode     = st.st_mode;
-
-    if (writen(ctx->tcp_fd, &meta, sizeof(meta)) != sizeof(meta)) return -1;
-    if (writen(ctx->tcp_fd, rel_path, meta.name_len) != (ssize_t)meta.name_len) return -1;
-
-    file_response_t resp;
-    if (readn(ctx->tcp_fd, &resp, sizeof(resp)) != sizeof(resp)) return -1;
-
-    if (resp.response == RESP_SKIP) {
-        printf("[thread] Skip: %s\n", rel_path);
-        return 0;
-    } else if (resp.response == RESP_USE_UDP) {
-        if (send_file_udp(ctx, full_path, resp.file_id, meta.file_size) < 0)
-            return -1;
-        uint32_t ack = 0;
-        if (readn(ctx->tcp_fd, &ack, sizeof(ack)) != sizeof(ack)
-                || ack != RESP_OK) {
-            fprintf(stderr, "[thread] UDP finalize failed: %s\n", rel_path);
-            return -1;
-        }
-    } else if (resp.response == RESP_SEND_DATA) {
-        int fd = open(full_path, O_RDONLY);
-        if (fd < 0) { perror("open"); return -1; }
-        off_t off = 0;
-        while (off < (off_t)meta.file_size) {
-            ssize_t r = sendfile(ctx->tcp_fd, fd, &off, meta.file_size - off);
-            if (r < 0) {
-                if (errno == EINTR) continue;
-                perror("sendfile"); close(fd); return -1;
-            }
-            if (r == 0) break;
-        }
-        close(fd);
-        uint32_t ack = 0;
-        if (readn(ctx->tcp_fd, &ack, sizeof(ack)) != sizeof(ack)
-                || ack != RESP_OK) {
-            fprintf(stderr, "[thread] TCP finalize failed: %s\n", rel_path);
-            return -1;
-        }
-    } else {
-        fprintf(stderr, "[thread] Server rejected %s (code %u)\n",
-                rel_path, resp.response);
-        return -1;
-    }
-
-    atomic_fetch_add(&g_bytes_sent, meta.file_size);
-    atomic_fetch_add(&g_files_sent, 1);
-    printf("[thread] Sent: %s\n", rel_path);
-    return 0;
-}
-
 // ─── UDP session setup (called once per worker if -u) ─────────────────────
 
 static int setup_udp(sync_ctx_t *ctx, const char *host) {
@@ -473,7 +326,7 @@ static int collect_files(const char *base, const char *sub, file_task_t **list,
     while ((e = readdir(dir)) != NULL) {
         if (!strcmp(e->d_name, ".") || !strcmp(e->d_name, "..")) continue;
 
-        char rel[2048], full[2048];
+        char rel[1024], full[2048];
         if (sub && sub[0]) {
             snprintf(rel,  sizeof(rel),  "%s/%s", sub, e->d_name);
         } else {

src/server.c

@@ -353,7 +353,7 @@ void handle_client(int sock_fd, const char *dest_dir) {
                 // Check if file already exists with same size and checksum (skip if so)
                 struct stat existing_st;
                 if (stat(target_path, &existing_st) == 0 && 
-                    existing_st.st_size == meta.file_size &&
+                    (uint64_t)existing_st.st_size == meta.file_size &&
                     S_ISREG(existing_st.st_mode)) {
                     // File exists with same size - check checksum
                     uint64_t existing_checksum = fast_hash_file(target_path, meta.file_size);