From b99c7ce8573f8650c4cafdc23ac7f44da46f4927 Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Sat, 16 Jan 2016 19:34:22 +0100 Subject: [PATCH] uclient-fetch: add support for resuming downloads Signed-off-by: Felix Fietkau --- uclient-fetch.c | 112 +++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 105 insertions(+), 7 deletions(-) diff --git a/uclient-fetch.c b/uclient-fetch.c index da11268..fa60eb3 100644 --- a/uclient-fetch.c +++ b/uclient-fetch.c @@ -17,12 +17,15 @@ */ #define _GNU_SOURCE +#include #include #include #include #include #include #include +#include +#include #include @@ -53,17 +56,23 @@ static char *auth_str; static char **urls; static int n_urls; static int timeout; +static bool resume, cur_resume; +static int init_request(struct uclient *cl); static void request_done(struct uclient *cl); -static int open_output_file(const char *path, bool create) +static int open_output_file(const char *path, uint64_t resume_offset) { char *filename = NULL; - int flags = O_WRONLY; + int flags; int ret; - if (create) - flags |= O_CREAT | O_EXCL; + if (cur_resume) + flags = O_RDWR; + else + flags = O_WRONLY | O_EXCL; + + flags |= O_CREAT; if (output_file) { if (!strcmp(output_file, "-")) { @@ -82,11 +91,30 @@ static int open_output_file(const char *path, bool create) ret = open(output_file, flags, 0644); free(filename); + if (ret < 0) + return ret; + + if (resume_offset && + lseek(ret, resume_offset, SEEK_SET) < 0) { + if (!quiet) + fprintf(stderr, "Failed to seek %"PRIu64" bytes in output file\n", resume_offset); + close(ret); + return -1; + } + + out_bytes += resume_offset; + return ret; } static void header_done_cb(struct uclient *cl) { + static const struct blobmsg_policy policy = { + .name = "content-range", + .type = BLOBMSG_TYPE_STRING + }; + struct blob_attr *attr; + uint64_t resume_offset = 0, resume_end, resume_size; static int retries; if (retries < 10 && uclient_http_redirect(cl)) { @@ -97,13 +125,48 @@ static void header_done_cb(struct uclient *cl) return; } - retries = 0; + if (cl->status_code == 204 && cur_resume) { + /* Resume attempt failed, try normal download */ + cur_resume = false; + init_request(cl); + return; + } + switch (cl->status_code) { + case 416: + if (!quiet) + fprintf(stderr, "File download already fully retrieved; nothing to do.\n"); + request_done(cl); + break; + case 206: + if (!cur_resume) { + if (!quiet) + fprintf(stderr, "Error: Partial content received, full content requested\n"); + error_ret = 8; + request_done(cl); + break; + } + + blobmsg_parse(&policy, 1, &attr, blob_data(cl->meta), blob_len(cl->meta)); + if (!attr) { + if (!quiet) + fprintf(stderr, "Content-Range header is missing\n"); + error_ret = 8; + break; + } + + if (sscanf(blobmsg_get_string(attr), "bytes %"PRIu64"-%"PRIu64"/%"PRIu64, + &resume_offset, &resume_end, &resume_size) != 3) { + if (!quiet) + fprintf(stderr, "Content-Range header is invalid\n"); + error_ret = 8; + break; + } case 204: case 200: if (no_output) break; - output_fd = open_output_file(cl->url->location, true); + output_fd = open_output_file(cl->url->location, resume_offset); if (output_fd < 0) { if (!quiet) perror("Cannot open output file"); @@ -152,6 +215,29 @@ static void msg_connecting(struct uclient *cl) fprintf(stderr, "Connecting to %s:%d\n", addr, port); } +static void check_resume_offset(struct uclient *cl) +{ + char range_str[64]; + struct stat st; + char *file; + int ret; + + file = uclient_get_url_filename(cl->url->location, "index.html"); + if (!file) + return; + + ret = stat(file, &st); + free(file); + if (ret) + return; + + if (!st.st_size) + return; + + snprintf(range_str, sizeof(range_str), "bytes=%"PRIu64"-", (uint64_t) st.st_size); + uclient_http_set_header(cl, "Range", range_str); +} + static int init_request(struct uclient *cl) { int rc; @@ -174,6 +260,8 @@ static int init_request(struct uclient *cl) uclient_http_reset_headers(cl); uclient_http_set_header(cl, "User-Agent", user_agent); + if (cur_resume) + check_resume_offset(cl); if (post_data) { uclient_http_set_header(cl, "Content-Type", "application/x-www-form-urlencoded"); @@ -192,6 +280,7 @@ static void request_done(struct uclient *cl) if (n_urls) { uclient_set_url(cl, *urls, auth_str); n_urls--; + cur_resume = resume; error_ret = init_request(cl); if (error_ret == 0) return; @@ -324,6 +413,7 @@ enum { L_POST_DATA, L_SPIDER, L_TIMEOUT, + L_CONTINUE, }; static const struct option longopts[] = { @@ -335,6 +425,7 @@ static const struct option longopts[] = { [L_POST_DATA] = { "post-data", required_argument }, [L_SPIDER] = { "spider", no_argument }, [L_TIMEOUT] = { "timeout", required_argument }, + [L_CONTINUE] = { "continue", no_argument }, {} }; @@ -351,7 +442,7 @@ int main(int argc, char **argv) init_ustream_ssl(); - while ((ch = getopt_long(argc, argv, "O:qsU:", longopts, &longopt_idx)) != -1) { + while ((ch = getopt_long(argc, argv, "cO:qsU:", longopts, &longopt_idx)) != -1) { switch(ch) { case 0: switch (longopt_idx) { @@ -387,10 +478,16 @@ int main(int argc, char **argv) case L_TIMEOUT: timeout = atoi(optarg); break; + case L_CONTINUE: + resume = true; + break; default: return usage(progname); } break; + case 'c': + resume = true; + break; case 'U': user_agent = optarg; break; @@ -451,6 +548,7 @@ int main(int argc, char **argv) if (ssl_ctx && default_certs) init_ca_cert(); + cur_resume = resume; rc = init_request(cl); if (!rc) { /* no error received, we can enter main loop */ -- 2.30.2