diff --git a/util.c b/util.c index 8acce23..81449b7 100644 --- a/util.c +++ b/util.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -26,6 +27,7 @@ #include #include "util.h" +#include "iov.h" #include "passt.h" #include "packet.h" #include "log.h" @@ -574,3 +576,36 @@ int do_clone(int (*fn)(void *), char *stack_area, size_t stack_size, int flags, return clone(fn, stack_area + stack_size / 2, flags, arg); #endif } + +/* write_remainder() - write the tail of an IO vector to an fd + * @fd: File descriptor + * @iov: IO vector + * @iovcnt: Number of entries in @iov + * @skip: Number of bytes of the vector to skip writing + * + * Return: 0 on success, -1 on error (with errno set) + * + * #syscalls write writev + */ +int write_remainder(int fd, const struct iovec *iov, int iovcnt, size_t skip) +{ + int i; + + while ((i = iov_skip_bytes(iov, iovcnt, skip, &skip)) < iovcnt) { + ssize_t rc; + + if (skip) { + rc = write(fd, (char *)iov[i].iov_base + skip, + iov[i].iov_len - skip); + } else { + rc = writev(fd, &iov[i], iovcnt - i); + } + + if (rc < 0) + return -1; + + skip += rc; + } + + return 0; +} diff --git a/util.h b/util.h index e0df26c..de6816a 100644 --- a/util.h +++ b/util.h @@ -229,6 +229,7 @@ void write_pidfile(int fd, pid_t pid); int __daemon(int pidfile_fd, int devnull_fd); int fls(unsigned long x); int write_file(const char *path, const char *buf); +int write_remainder(int fd, const struct iovec *iov, int iovcnt, size_t skip); /** * mod_sub() - Modular arithmetic subtraction