--- /dev/null
+#include "safeio.h"
+#include "socket.h"
+#include "stringf.h"
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <dirent.h>
+#include <poll.h>
+#include <climits>
+#include <cstdlib>
+#include <csignal>
+
+// https://stackoverflow.com/a/8615450/2995591
+#include <glob.h> // glob(),globfree()
+#include <cstring> // memset()
+#include <vector>
+#include <string>
+
+static std::vector<std::string> cxxglob(const std::string pattern) {
+ glob_t glob_result;
+ memset(&glob_result,0,sizeof(glob_result));
+ int return_value=glob(pattern.c_str(),GLOB_TILDE,NULL,&glob_result);
+ if (return_value)
+ fatal("glob() failed with return_value %s",return_value);
+ vector<string> filenames;
+ filenames.reserve(glob_result.gl_pathc);
+ for (size_t i = 0; i < glob_result.gl_pathc; ++i)
+ filenames.push_back(string(glob_result.gl_pathv[i]));
+ globfree(&glob_result);
+ return filenames;
+}
+
+// FIXME: Use C++17
+static bool fd_is_open(const char *execname,const char *fn) {
+ const char slashproc[]("/proc");
+ DIR *dir(opendir(slashproc));
+ if (!dir)
+ fatal("Cannot opendir %s: %m",slashproc);
+ bool retval(false);
+ for (;;) {
+ errno=0;
+ const struct dirent *de=readdir(dir);
+ if (!de) {
+ if (errno)
+ fatal("Cannot readdir %s: %m",slashproc);
+ break;
+ }
+ if (!isdigit(de->d_name[0]))
+ continue;
+
+ char buf[PATH_MAX];
+ ssize_t got(readlinkat(dirfd(dir),stringf("%s/exe",de->d_name).c_str(),buf,sizeof(buf)));
+ if (got==-1||got==sizeof(buf))
+ continue;
+ buf[got]=0;
+ char *s=strrchr(buf,'/');
+ if (!s)
+ continue;
+ if (strcmp(s+1,execname)!=0)
+ continue;
+
+ string procpidfd(stringf("/proc/%s/fd",de->d_name));
+ DIR *fddir(opendir(procpidfd.c_str()));
+ if (!fddir)
+ fatal("Cannot opendir %s: %m",procpidfd.c_str());
+ for (;;) {
+ errno=0;
+ const struct dirent *de=readdir(fddir);
+ if (!de) {
+ if (errno)
+ fatal("Cannot readdir %s: %m",procpidfd.c_str());
+ break;
+ }
+ if (!isdigit(de->d_name[0]))
+ continue;
+ char buf[PATH_MAX];
+ ssize_t got(readlinkat(dirfd(fddir),de->d_name,buf,sizeof(buf)));
+ if (got==-1||got==sizeof(buf))
+ continue;
+ buf[got]=0;
+ if (strcmp(buf,fn)==0) {
+ retval=true;
+ break;
+ }
+ }
+ if (closedir(fddir))
+ fatal("Cannot closedir %s: %m",procpidfd.c_str());
+ if (retval)
+ break;
+ }
+ if (closedir(dir))
+ fatal("Cannot closedir %s: %m",slashproc);
+ return retval;
+}
+
+int main(int argc,char **argv) {
+ static struct sigaction sigchld;
+ sigchld.sa_handler=SIG_DFL;
+ sigchld.sa_flags=SA_NOCLDWAIT;
+ int err(sigaction(SIGCHLD,&sigchld,nullptr));
+ assert(!err);
+
+ if (argc!=1+2&&argc!=1+3)
+ fatal("streamfer-server [<listen-host>:]<listen-port> <prefix> [follow-fd-of-executable-basename]");
+ string prefix;
+ if (argc>=1+2&&*argv[2])
+ prefix=argv[2];
+ const char *execname(nullptr);
+ if (argc>=1+3)
+ execname=argv[3];
+ int listen_fd(socket_bind(argv[1]));
+ int client_fd;
+ for (;;) {
+ client_fd=socket_accept(listen_fd,[&](int client_fd,string addr) {
+ warning("%d:%s",client_fd,addr.c_str());
+ });
+ int child(fork());
+ assert(child!=-1);
+ if (!child)
+ break;
+ int err(close(client_fd));
+ assert(!err);
+ }
+ err=close(listen_fd);
+ assert(!err);
+
+ string pattern(read_safe_string(client_fd));
+ std::vector<std::string> matched(cxxglob(pattern));
+ for (size_t ix=0;ix<matched.size()-1;++ix) {
+ const std::string &a(matched[ix ]);
+ const std::string &b(matched[ix+1]);
+ int err(strcmp(a.c_str(),b.c_str()));
+ if (err>=0)
+ fatal("glob: strcmp(\"%s\",\"%s\")=%d",a.c_str(),b.c_str(),err);
+ }
+ string last(read_safe_string(client_fd));
+ size_t lastix(SIZE_MAX);
+ for (size_t ix=0;ix<matched.size();++ix) {
+ const std::string &member(matched[ix]);
+ if (strcmp(last.c_str(),member.c_str())>0)
+ assert(lastix==SIZE_MAX);
+ else if (lastix==SIZE_MAX)
+ lastix=ix;
+ }
+ if (lastix==SIZE_MAX)
+ fatal("Requested too new file");
+ uint64_t offset;
+ read_safe(client_fd,offset);
+ const string *fnp;
+ int file_fd=-1;
+ struct stat statbuf;
+ for (;lastix<matched.size();file_fd=-1,++lastix) {
+ fnp=&matched[lastix];
+ const string &fn(*fnp);
+ file_fd=open(fn.c_str(),O_RDONLY);
+ if (file_fd==-1) {
+ if (errno!=ENOENT)
+ fatal("Cannot open %s: %m",fn.c_str());
+ continue;
+ }
+ int err(fstat(file_fd,&statbuf));
+ assert(!err);
+ if (offset<(uint64_t)statbuf.st_size)
+ break;
+ if (offset>(uint64_t)statbuf.st_size)
+ warning("File %s has transferred %zu < %zu which is its size",fn.c_str(),(size_t)offset,(size_t)statbuf.st_size);
+ if (lastix==matched.size()-1&&execname)
+ break;
+ err=close(file_fd);
+ assert(!err);
+ offset=0;
+ }
+ if (file_fd==-1) {
+ string empty("");
+ write_safe(client_fd,empty);
+ fatal("No more files to transfer");
+ }
+ const string &fn(*fnp);
+ const char *fn_canon(nullptr);
+ if (!prefix.empty()||execname) {
+ fn_canon=realpath(fn.c_str(),nullptr);
+ if (!fn_canon)
+ fatal("realpath %s: %m",fn.c_str());
+ }
+ if (fn!=last)
+ offset=0;
+ if (!prefix.empty()&&strncmp(prefix.c_str(),fn_canon,prefix.length())!=0)
+ fatal("prefix=\"%s\" realpath=\"%s\"",prefix.c_str(),fn_canon);
+ warning("%s @%zu",fn.c_str(),(size_t)offset);
+ write_safe(client_fd,fn);
+ write_safe(client_fd,statbuf.st_mtim);
+ off_t got(lseek(file_fd,offset,SEEK_SET));
+ assert((uint64_t)got==offset);
+ struct pollfd fds;
+ fds.fd=client_fd;
+ fds.events=POLLIN|POLLPRI|POLLRDHUP;
+ for (;;) {
+ transfer(file_fd,fn.c_str(),client_fd,"client fd");
+ if (!fn_canon||!fd_is_open(execname,fn_canon))
+ break;
+ int err(poll(&fds,1,1000/*ms*/));
+ if (err==-1)
+ fatal("poll client fd: %m");
+ if (err==1)
+ fatal("poll client fd: revents=0x%x",fds.revents);
+ assert(err==0);
+ }
+}
git://git.jankratochvil.net / nethome.git / blobdiff